Imaging Presacral Masses

IMAGING OF PRESACRAL IMAGING OF PRESACRAL MASSESMASSES

speaker: kiran speaker: kiran

MODERATOR:MODERATOR:PROF.O.P. SHARMAPROF.O.P. SHARMA

INTRODUCTIONINTRODUCTION Mass present between perirectal fasciaMass present between perirectal fascia

and the sacrococcygeal part of spine. Imaging plays an important role in the Imaging plays an important role in the

detection and differentiation of these detection and differentiation of these masses.masses.

Information obtained is critical for Information obtained is critical for management ,especially surgical management ,especially surgical planning.planning.

Usual symptoms are ,change in bowel Usual symptoms are ,change in bowel habits,low back and sacral pain, habits,low back and sacral pain, abdominal pain,palpable mass, urinary abdominal pain,palpable mass, urinary symptoms, anal discharge and bleeding. symptoms, anal discharge and bleeding.

TYPES OF MASSTYPES OF MASS

Congenital and developmental masses.Congenital and developmental masses. Neurogenic MassesNeurogenic Masses Inflammatory MassesInflammatory Masses Mesenchymal MassesMesenchymal Masses Lymphomatous MassesLymphomatous Masses Extension of sacral bone tumors Other presacral masses

CLASSIFICATION 2CLASSIFICATION 2

A.A. SOLIDSOLID

.sacrococcygeal teratoma.sacrococcygeal teratoma

.neuroblastoma.neuroblastoma

.rhabdomyosarcoma.rhabdomyosarcoma

.fibroma.fibroma

.lipoma.lipoma

.lymphoma.lymphoma

.sacral bone tumours etc.sacral bone tumours etc

CYSTICCYSTIC

AbscessAbscess Rectal duplicationRectal duplication HematomaHematoma LymhoceleLymhocele Neurentric cystNeurentric cyst Sacral osteomyelitisSacral osteomyelitis Ulcerative colitisUlcerative colitis Anterior meningoceleAnterior meningocele

CONGENITAL AND CONGENITAL AND DEVELOPMENTAL MASSESDEVELOPMENTAL MASSES

Germ cell tumors - sacrococcygeal Germ cell tumors - sacrococcygeal teratoma,germinomatous and teratoma,germinomatous and nongerminomatous germ cell tumors.nongerminomatous germ cell tumors.

Anterior sacral meningoceleAnterior sacral meningocele Developmental cysts - epidermoid cyst, Developmental cysts - epidermoid cyst,

dermoid cyst, enteric cysts [rectal duplication dermoid cyst, enteric cysts [rectal duplication cyst, tailgut cyst])cyst, tailgut cyst])

Cystic lymphangiomaCystic lymphangioma LipomaLipoma

SACROCOCCYGEAL TERATOMASACROCOCCYGEAL TERATOMA

Teratoma located at the base of the coccyx.Teratoma located at the base of the coccyx. Most common tumor of the newborn period, Most common tumor of the newborn period,

with a prevalence of 0.25-0.28:10,000 live with a prevalence of 0.25-0.28:10,000 live births; M:F 1:4 ratio.births; M:F 1:4 ratio.

Derived from the pleuripotent cells of Derived from the pleuripotent cells of Hensen"s nodes that migrate caudally and Hensen"s nodes that migrate caudally and come to lie within the coccyx.come to lie within the coccyx.

Tumors before 2mnths of age & cystic Tumors before 2mnths of age & cystic lesions are usually benign.lesions are usually benign.

ALTMAN CLASSIFICATION SYSTEM FOR SACROCOCCYGEAL TERATOMAS

Type I - Predominantly Type I - Predominantly external masses with a external masses with a small presacral component.small presacral component.

Type II - External masses Type II - External masses with a significant with a significant intrapelvic component.intrapelvic component.

Type III- External masses Type III- External masses with a pelvic and abdominal with a pelvic and abdominal component.component.

Type IV - Internal masses Type IV - Internal masses with an intrapelvic and with an intrapelvic and abdominal location.abdominal location.

IMAGING FINDINGSIMAGING FINDINGS

Cystic components typically appear as anechoic Cystic components typically appear as anechoic areas on USG.areas on USG.

MRI is the modality of choice because of the MRI is the modality of choice because of the superior depiction of soft tissues and preferred for superior depiction of soft tissues and preferred for both initial diagnosis and recurrence survillence.both initial diagnosis and recurrence survillence.

Benign are predominantly cystic have attenuation Benign are predominantly cystic have attenuation similar to that of fluid on CT.similar to that of fluid on CT.

On MRI cystic areas appear as fluid on T1 and T2 On MRI cystic areas appear as fluid on T1 and T2 images ,areas of fatty tissue show high signal images ,areas of fatty tissue show high signal intensity, calification and bone dipicted as signal intensity, calification and bone dipicted as signal void. void.

MATURE SACROCOCCYGEAL TERATOMAMATURE SACROCOCCYGEAL TERATOMA

Frontal pelvic Frontal pelvic radiograph reveals radiograph reveals ischiopubic separation ischiopubic separation due to a presacral due to a presacral mass. mass.

MATURE SACROCOCCYGEAL TERATOMAMATURE SACROCOCCYGEAL TERATOMA

Axial unenhanced CT Axial unenhanced CT scan through the upper scan through the upper portion of the lesion portion of the lesion shows attenuation similar shows attenuation similar to that of water, a finding to that of water, a finding indicative of a indicative of a predominant cystic predominant cystic component.component.

BENIGN SACROCOCCYGEAL TERATOMA

Axial unenhanced CT Axial unenhanced CT scan at the level of the scan at the level of the coccyx shows a coccyx shows a presacral mass with presacral mass with multilocular cystic (C) multilocular cystic (C) and solid (S) and solid (S) components. The components. The rectosigmoid (R) rectosigmoid (R) segment of the colon segment of the colon is displaced anteriorly.is displaced anteriorly.

RECURRENT SACROCOCCYGEAL TERATOMA

Axial T1-weighted Axial T1-weighted spin-echo MR image spin-echo MR image (a)axial T2-weighted (a)axial T2-weighted fat-saturated turbo fat-saturated turbo spin-echo imagespin-echo image

RECURRENT SACROCOCCYGEAL TERATOMA

Two well-defined Two well-defined round cystic masses round cystic masses with predominantly with predominantly intermediate signal intermediate signal intensity in a and high intensity in a and high signal intensity in b. signal intensity in b. High-signal-intensity High-signal-intensity areas in a represent areas in a represent fat. The rectum (R) was fat. The rectum (R) was displaced displaced anterolaterally. The anterolaterally. The coccyx previously was coccyx previously was removed.removed.

MALIGNANT SACROCOCCYGEAL TERATOMA

Intermediate to low Intermediate to low signal intensity on signal intensity on the T2-weighted fat-the T2-weighted fat-saturated image saturated image


Visible are involvement Visible are involvement of the distal sacrum of the distal sacrum and coccyx and coccyx (arrowheads in b), (arrowheads in b), anterior displacement anterior displacement of the vagina and of the vagina and uterus (arrows in b), uterus (arrows in b), and superior and and superior and anterior displacement anterior displacement of the bladder (B).of the bladder (B).


(a, b) Axial (a, b) Axial unenhanced T1-unenhanced T1-weighted MR image weighted MR image

(a)Axial T2-weighted (a)Axial T2-weighted fat-saturated turbo fat-saturated turbo spin-echo imagespin-echo image


At the level of the At the level of the pelvis demonstrate a pelvis demonstrate a well-defined lobular well-defined lobular cystic mass with cystic mass with multiple septa that has multiple septa that has displaced the rectum displaced the rectum (R), uterus (U), and (R), uterus (U), and bladder (B) anteriorly. bladder (B) anteriorly. The images also show The images also show a subcutaneous left a subcutaneous left inguinal soft-tissue inguinal soft-tissue mass (arrow).mass (arrow).


Axial T1-weighted fat-Axial T1-weighted fat-saturated image saturated image obtained with obtained with intravenous contrast intravenous contrast material shows material shows contrast enhancement contrast enhancement of the septa and rim of of the septa and rim of the cystic mass and the cystic mass and the left inguinal soft-the left inguinal soft-tissue mass (arrow). tissue mass (arrow). The latter was The latter was diagnosed as diagnosed as metastatic adenopathy.metastatic adenopathy.

First trimester detection of a sacral massFirst trimester detection of a sacral mass

Longitudinal view of lumbosacral spine reveals an Longitudinal view of lumbosacral spine reveals an intact neural tube, differentiating the teratoma from intact neural tube, differentiating the teratoma from

a complicated meningomyclocele. a complicated meningomyclocele.

Fig 1- Caudal view at delivery. Fig 1- Caudal view at delivery. Fig 2 - The complexity of the teratoma is appreciated Fig 2 - The complexity of the teratoma is appreciated prior to surgical resection. The primary mass originated prior to surgical resection. The primary mass originated from the ischium while the pedunculated aspect from the ischium while the pedunculated aspect originated from the coccyx. originated from the coccyx.

CURRARINO TRIADCURRARINO TRIAD

Also known as ASP triad.Also known as ASP triad. Anorectal malformations, Anorectal malformations,

Sacrococcygeal osseus defect & Sacrococcygeal osseus defect & Presacral masses.Presacral masses.

Autosomal dominant in 50% of casesAutosomal dominant in 50% of cases Meningocele and teratoma are most Meningocele and teratoma are most

commonly associated.commonly associated.

CURRARINO TRIAD

Pelvic radiograph shows a scimitar

sacrum with osseous defect on the right side (arrows).

CURRARINO TRIAD

Axial unenhanced CT scan demonstrates a welldefined mass (arrow) with attenuation slightly lower than that of fluid, a feature that represents fatty tissue in a dermoid, and leftward displacement of the rectum. B bladder.

CURRARINO TRIAD

Image from a barium enema study performed after atresia repair also shows the dermoid at the low presacral level and anterior displacement of the rectum (arrow).

ANTERIOR SACRAL ANTERIOR SACRAL MENINGOCELE.MENINGOCELE.

Herniation of csf filled dura through Herniation of csf filled dura through sacral foramen or a defect in sacrum.sacral foramen or a defect in sacrum.

Incidence 1 in 40000.Incidence 1 in 40000. 80% in first decade.80% in first decade. Nerve roots ,neural elements within Nerve roots ,neural elements within

sac & various osseous defects should sac & various osseous defects should be assessed.be assessed.

MRI modality of choice.MRI modality of choice.

DERMOID CYSTDERMOID CYST

Contains mucoid,fatty ( 67-75%) Contains mucoid,fatty ( 67-75%) &calcific components(31%).&calcific components(31%).

Only a minority are presacral in Only a minority are presacral in location.location.

Demonstration of fatty tissue and Demonstration of fatty tissue and calcific tissue pathognomonic.calcific tissue pathognomonic.

RECTAL DUPLICATION CYSTRECTAL DUPLICATION CYST

Three histologic criterias.Three histologic criterias.

1. Presence of two layers of smooth 1. Presence of two layers of smooth

muscle.muscle.

2. Continuity with the rectum.2. Continuity with the rectum.

3. Mucosal lining similar to rectal 3. Mucosal lining similar to rectal mucosa.mucosa.

RECTAL DUPLICATION

Oblique radiograph of the pelvis, obtained during a barium enema examination, demonstrates a well-defined retrorectal tubular communication (arrowheads) with the rectum.

TAILGUT CYSTTAILGUT CYST

Persistent remnants of embyologic Persistent remnants of embyologic gut.gut.

They are uni or multilocular.They are uni or multilocular. Contain mucin secreting cells.Contain mucin secreting cells. Content is predominantly mucoid.Content is predominantly mucoid. No smooth muscle layerNo smooth muscle layer

IMAGING FINDINGS-IMAGING FINDINGS-Enteric cysts.Enteric cysts.

Conventional radiograph shows widening of Conventional radiograph shows widening of retrorectal space.retrorectal space.

Barium study show communication between Barium study show communication between cyst and intestinal lumen.cyst and intestinal lumen.

USG shows uni or multilocular cystic lesions USG shows uni or multilocular cystic lesions with varying echogenecities of mucoid and with varying echogenecities of mucoid and inflmmatory debris.inflmmatory debris.

CT shows welldefined uni or multilocular thin CT shows welldefined uni or multilocular thin walled cysts with low attenuation , without walled cysts with low attenuation , without contrast enhancement.contrast enhancement.

Imaging findings.Imaging findings.

MRI demonstrates well marginated ,thin walled MRI demonstrates well marginated ,thin walled lesions with low signal intensity on T1 and high lesions with low signal intensity on T1 and high signal intensity on T2 weighted images.signal intensity on T2 weighted images.

Mucoid content of tailgut cysts cause them to Mucoid content of tailgut cysts cause them to have high signal intensity on T1 weighted have high signal intensity on T1 weighted images.images.

Malignant degeneration if present will have Malignant degeneration if present will have asymmetric ,irregular wall thickening with asymmetric ,irregular wall thickening with heterogenous contrast enhancement.heterogenous contrast enhancement.

TAILGUT CYST

Axial CT scan obtained with oral and intravenous contrast material at the level of the symphysis pubis demonstrates a lobular well-defined fluid-attenuation mass that compresses the barium-filled rectum (R) anterolaterally.

TAILGUT CYST

Axial T2-weighted fat-saturated MR imageshows high signal intensity in the mass. The intermediate attenuation seen in the mass in a reflects its mucoid content. R rectum.

NEUROGENIC MASSES

Neuroblastoma.Neuroblastoma. Ganglioneuroblastoma.Ganglioneuroblastoma. Ganglioneuroma.Ganglioneuroma. Neurofibroma.Neurofibroma. Schwannoma.Schwannoma.

NEUROBLASTOMANEUROBLASTOMA

Accounts for 10% of peadiatric cancersAccounts for 10% of peadiatric cancers Median age of diagnosis 22 months.Median age of diagnosis 22 months. 95% are diagnosed within first decade.95% are diagnosed within first decade. 70% abdominal,20% mediastinal &70% abdominal,20% mediastinal & 2-3% are pelvic.2-3% are pelvic. Because of midline location ,considered Because of midline location ,considered

stage III.stage III. 70% show calcification.70% show calcification.

IMAGING FINDINGS.IMAGING FINDINGS.

Detection and staging of neuroblastoma is Detection and staging of neuroblastoma is accomplished by CT,MRI and nuclear imaging.accomplished by CT,MRI and nuclear imaging.

Bone scintigraphy with technitium 99 and Bone scintigraphy with technitium 99 and skeletal radiography are used to determine skeletal radiography are used to determine areas of involvement.areas of involvement.

Radiographic findings are nonspecific and Radiographic findings are nonspecific and include calcifications in 30%.include calcifications in 30%.

USG shows an heterogenous mass if areas of USG shows an heterogenous mass if areas of hemorrhage and necrosis are present.hemorrhage and necrosis are present.

Doppler US helps to determine relation of Doppler US helps to determine relation of tumour with the vessels.tumour with the vessels.

Imaging findings.Imaging findings.

CT demonstrates location , boundries and extension of CT demonstrates location , boundries and extension of tumours.tumours.

Calcifications are seen in more than 80% at CT.Calcifications are seen in more than 80% at CT. Small tumours are homogenous in appearance , larger Small tumours are homogenous in appearance , larger

show heterogenous attenuation because of show heterogenous attenuation because of hemorrhage and necrosis.hemorrhage and necrosis.

On MRI , lesions show low signal intensity and On MRI , lesions show low signal intensity and heterogenous contrast enhancement on T1 and high heterogenous contrast enhancement on T1 and high signal intensity in T2 weighted images.signal intensity in T2 weighted images.

Hemorrhagic areas are of high signal intensity on T1 Hemorrhagic areas are of high signal intensity on T1 and cystic & necrotic areas show high intensity on T2 and cystic & necrotic areas show high intensity on T2 weighted images.weighted images.

NEUROBLASTOMA

Axial US image of the upper pelvis demonstrates a large, well-defined, solid mass that contains a small cystic area (curved arrow); multiple smaller areas of high echogenicity representing calcifications; the right iliac bone (straight arrow); and the sacral vertebrae (arrowhead).

NEUROBLASTOMA

Axial CT scan of the pelvis, obtained with intravenous contrast material, demonstrates a well-defined and heterogeneously enhanced presacral mass that contains scattered foci of calcifications. The mass has encroached on the neural foramen (arrow) in the left side and has displaced the rectosigmoid (R) colon segment anterolaterally.

PRESACRAL NEUROBLASTOMA

Axial unenhanced CT scan of the pelvis reveals a low-attenuation presacral mass that has displaced the rectosigmoid (R) colon segment leftward and that contains subtle punctate calcifications (arrows).

PRESACRAL NEUROBLASTOMA

Axial CT scan obtained with intravenous contrast material shows heterogeneous enhancement in the mass but no pelvic vessel involvement.

NEUROBLASTOMA

Axial pelvic CT scan obtained with intravenous contrast material shows a large mass that contains areas of low attenuation consistent with necrosis. The mass extends to the right S1 vertebral foramen (arrow) and has displaced the rectum to the right side and the bladder (arrowhead) anteriorly.

NEUROBLASTOMA

Sagittal T1-weighted MR image of the pelvis demonstrates a large presacral mass that extends to the neural foramen (arrow). The mass has predominant intermediate signal intensity and multiple rimlike areas of high signal intensity (arrowheads) that are presumably due to hemorrhage.

NEUROBLASTOMA

Sagittal T2-weighted fat-saturated MR image shows heterogeneous, predominantly high signal intensity in the mass (arrowheads).

GANGLIONEUROMAGANGLIONEUROMA

Rare benign tumour.Rare benign tumour. Evolve from regressed neuroblastoma or Evolve from regressed neuroblastoma or

ganglioneuroblastomaganglioneuroblastoma Seen typically in second decade.Seen typically in second decade. Most common locations in order of Most common locations in order of

frequency are, posteriormediastinum, frequency are, posteriormediastinum, retroperitoneum,adrenals & neck.retroperitoneum,adrenals & neck.

More homogenous & two thirds show More homogenous & two thirds show calcification in imaging.calcification in imaging.

GANGLIONEUROMA

Sagittal T2-weighted MR image shows a high-signalintensity presacral ganglioneuroma that distorts the distal sacrum (arrow) and has displaced the bladder(B) anteriorly.

NEUROFIBROMANEUROFIBROMA

Occur singly or in multiples in NF-1.Occur singly or in multiples in NF-1. NF_1 autosomal dominant.NF_1 autosomal dominant. Occurs 1 in 2000-4000.Occurs 1 in 2000-4000. Abdominal involvement most likely to occur in Abdominal involvement most likely to occur in

retroperitoneal,mesentric & paraspinal regions.retroperitoneal,mesentric & paraspinal regions. resembles lymphadenopathy on CT with attenuation less resembles lymphadenopathy on CT with attenuation less

than that of soft tissues.than that of soft tissues. On T1 weighted image, homogenously isointense or mildly On T1 weighted image, homogenously isointense or mildly

hyperintense in comparision to muscle.hyperintense in comparision to muscle. On T2 weighted image,”target” like appearance with a rim of On T2 weighted image,”target” like appearance with a rim of

myxomatus material and a central zone of low signal intensity myxomatus material and a central zone of low signal intensity indicating a fibrous core.indicating a fibrous core.

NEUROFIBROMATOSIS

Axial pelvic CT scan obtained with intravenous contrast material shows well-circumscribed bilateral masses with soft-tissue attenuation, anterior to the sacrum, that have compressed the rectosigmoid colon segment and displaced the bladder. Neurofibromas also are visible in the inguinal regions.

NEUROFIBROMATOSIS

Axial T2-weighted fat-saturated MR image of the middle pelvis in an 18-year-old male patient shows multiple bilateral target signs indicative of intrapelvic neurofibromas, which extend into the inguinal regions. A subcutaneous lesion also is visible in the left buttock.

NFNF

NEUROFIBROMATOSIS

Axial T2- weighted MR image in an 11-year-old girl with spasticity of the lower extremities shows multiple lesions with the characteristic target sign: a large central region of hypointense signal representing a fibrous core, surrounded by a rim of hyperintense signal indicative of myxoid material. Abnormal soft tissue has filled and expanded the spinal canal. The mass effect of the pelvic lesions has caused lateral displacement of the rectosigmoid (R) colon segment and anterosuperior displacement of the bladder (B).

SHWANNOMASHWANNOMA

1-5% originate in sacrum.1-5% originate in sacrum. Presents as large mass.Presents as large mass. On MRI ,heterogenous low signal On MRI ,heterogenous low signal

intensity on T1 & high signal intensity intensity on T1 & high signal intensity on T2 weighted images.on T2 weighted images.

Small cystic areas and a thin Small cystic areas and a thin pseudocapsule is noted.pseudocapsule is noted.

INFLAMMATORY MASSESINFLAMMATORY MASSES

Inflammatory bowel disease Inflammatory bowel disease (ulcerative colitis,Crohn disease).(ulcerative colitis,Crohn disease).

Perirectal abscess.Perirectal abscess. Granuloma.Granuloma.

PELVIC ABSCESSESPELVIC ABSCESSES

Secondary to, complicated Secondary to, complicated appendicitis,inflamatory bowel appendicitis,inflamatory bowel disorders & postoperative disorders & postoperative complications.complications.

May be related to extension from May be related to extension from upper primary site.upper primary site.

IMAGING CHARACTERISTICSIMAGING CHARACTERISTICS

Conventional radiograph show Conventional radiograph show intralesional air and air fluid levels.intralesional air and air fluid levels.

US shows a complex fluid US shows a complex fluid content,homogenosly echogenic & content,homogenosly echogenic & may have multiple septa.may have multiple septa.

PELVIC ABSCESS

Axial pelvic CT scan obtained with oral and intravenous contrast material demonstrates multiple fluid collections with peripheral enhancement that represent a postoperative abscess. The rectosigmoid colon segment (arrow) has been displaced laterally. U uterus.

MESENCHYMAL MASSESMESENCHYMAL MASSES

Rhabdomyo sarcoma Rhabdomyo sarcoma Undifferentiated sarcomaUndifferentiated sarcoma Vascular mass Fibroma

RHABDOMYOSARCOMA.RHABDOMYOSARCOMA.

Aggressive tumour accounts for 4-8% Aggressive tumour accounts for 4-8% of pediatric cancers.of pediatric cancers.

A presacral mass in a child older than A presacral mass in a child older than 8 yrs is highly suggestive of 8 yrs is highly suggestive of rhabdomyosarcomarhabdomyosarcoma

Bimodal 2-6yrs &14-18yrs.Bimodal 2-6yrs &14-18yrs.


Findings are general & nonspecificFindings are general & nonspecific Rational approach including Rational approach including

age ,clinical data & lab findings age ,clinical data & lab findings needed.needed.

CT shows heterogenous mass that CT shows heterogenous mass that rarely shows calcification and shows rarely shows calcification and shows variable enhancement.variable enhancement.

On contrast MRI heterogenous On contrast MRI heterogenous enhancement is noted.enhancement is noted.

RHABDOMYOSARCOMA

Axial pelvic CT scan Axial pelvic CT scan obtained with intravenous obtained with intravenous contrast material in a 15-contrast material in a 15-year-old boy initially treated year-old boy initially treated for proctitis depicts a for proctitis depicts a presacral mass that has presacral mass that has displaced the bladder (B) displaced the bladder (B) anteriorly and the anteriorly and the rectosigmoid colon segment rectosigmoid colon segment (arrow) to the left. The mass, (arrow) to the left. The mass, which is predominantly which is predominantly necrotic, shows peripheral necrotic, shows peripheral enhancement and some enhancement and some linear central enhancementlinear central enhancement

RHABDOMYOSARCOMA

Axial pelvic CT scan Axial pelvic CT scan obtained with oral and obtained with oral and intravenous contrast intravenous contrast material in an 8-month-old material in an 8-month-old boy demonstrates an boy demonstrates an infiltrative soft-tissue mass infiltrative soft-tissue mass that extends anteriorly, that extends anteriorly, causing deviation of the causing deviation of the urinary bladder (B), and urinary bladder (B), and posteriorly into both sciatic posteriorly into both sciatic notch regions. The mass notch regions. The mass contains punctate contains punctate calcifications. The spinal calcifications. The spinal canal is abnormally wide and canal is abnormally wide and shows increased soft-tissue shows increased soft-tissue attenuation (arrow). A attenuation (arrow). A bladder catheter (F) also is bladder catheter (F) also is visible.visible.

UNDIFFERENTIATED SARCOMA

Sagittal T1- weighted MR image shows a low-signal-intensity presacral soft-tissue mass that has displaced the rectum (R) anteriorly and has infiltrated the upper sacral vertebrae, which have an irregular appearance. Intermediatesignal- intensity soft tissue also is visible in the sacral spinal canal (arrows).

UNDIFFERENTIATED SARCOMA

Sagittal T2-weighted MR image more clearly depicts involvement of the sacrococcygeal vertebrae (arrow) as well as the spinal canal soft-tissuemass (arrowheads).

VASCULAR MASSESVASCULAR MASSES

This include venous, capillary,lymphatic This include venous, capillary,lymphatic or arterio-venous malformations.or arterio-venous malformations.

Hemangioma is the neoplastic variety.Hemangioma is the neoplastic variety. Pelvic hemangiomas present as large Pelvic hemangiomas present as large

lesions extending to mesentry,pelvic lesions extending to mesentry,pelvic sidewalls & rectum.sidewalls & rectum.

Pelvic vascular masses associated with Pelvic vascular masses associated with klippel trenaunay syndrome.klippel trenaunay syndrome.


CECT and MRI provide best depiction CECT and MRI provide best depiction of constituent and extent.of constituent and extent.

MRI shows a mixed intensity mass.MRI shows a mixed intensity mass.

VASCULAR MALFORMATION

Axial T2-weighted MR image demonstrates a mixedsignal- intensity mass (arrows) that involves the posterior sacrum as well as the presacral space.

LYMPHOMATOUS MASSESLYMPHOMATOUS MASSES

These includeThese include - true lymphomas –NHL (6% )- true lymphomas –NHL (6% ) -Hodgkins(5%)-Hodgkins(5%) -post trasplantation lymphoproliferative disorder.-post trasplantation lymphoproliferative disorder. Among NHL burkitt,burkitt like and B-cell Among NHL burkitt,burkitt like and B-cell

lymphomas are more common and present as lymphomas are more common and present as primary abdominal mass.primary abdominal mass.

Lymphnode involvement may be discrete or Lymphnode involvement may be discrete or conglomerate.conglomerate.

Isolated presacral mass very rare and usually Isolated presacral mass very rare and usually involves iliac nodes.involves iliac nodes.


First assessed with USG and then with CT First assessed with USG and then with CT for primary site and staging.for primary site and staging.

USG demonstrates a solid hypoechoeic USG demonstrates a solid hypoechoeic mass.mass.

On MR mass appears heterogenous with On MR mass appears heterogenous with low signal intensity on T1 and high signal low signal intensity on T1 and high signal intensity on T2 weighted images.intensity on T2 weighted images.

Post transplantation lymphomas are Post transplantation lymphomas are indistinguishable from other lymphomas.indistinguishable from other lymphomas.

BURKITT LYMPHOMA

Axial pelvic CT scan obtained with oral and intravenous contrast material shows a large heterogeneous mass with soft-tissue attenuation that extends to the presacral space and superior pelvis and encases the rectosigmoid colon segment (arrows).

BURKITT LYMPHOMA

(a, b)and sagittal (c) T2-weighted turbo spin-echo MR images obtained with (a) and without (b, c) fat saturation reveal a large heterogeneous pelvic mass with high signal intensity that has surrounded the rectum (arrow in a and c) and displaced the small-bowel loops superiorly. In b, note the left inguinal lymphadenopathy (arrowhead) and left acetabular involvement.

BURKITT LYMPHOMA

LYMPHOPROLIFERATIVE DISEASE

Axial CT scan obtained with oral and intravenous contrast material shows a minimally heterogeneous presacral mass.

EXTENSION OF SACRAL BONE TUMORS

Giant cell tumor Aneurysmal bone cyst Chordoma Osteoblastoma Ewing sarcoma family Osteogenic sarcoma

GIANT CELL TUMOURGIANT CELL TUMOUR

3-7% of all giant cell tumour arise from 3-7% of all giant cell tumour arise from vertebrae.vertebrae.

And most of it is from sacrum.And most of it is from sacrum. Its second most common tumour of sacrum Its second most common tumour of sacrum

after chordoma.after chordoma. Occur in second and through fourth decade Occur in second and through fourth decade

of life.of life. These are mostly lytic and destructive and These are mostly lytic and destructive and

contain no calcifications.contain no calcifications.


These tumours appear heterogenous on These tumours appear heterogenous on both CT and MRI.both CT and MRI.

Low attenuation areas on CT scan Low attenuation areas on CT scan represent necrosis.represent necrosis.

Hemorrhage is present when there is high Hemorrhage is present when there is high signal intensity on both T1 and T2 weighted signal intensity on both T1 and T2 weighted images.images.

Both CT and MRI show contrast Both CT and MRI show contrast enhancement.enhancement.

GIANT CELL TUMOR

Axial pelvic CT scan obtained with intravenous contrast material shows a large and expansile osteolytic mass (arrow) in the upper sacrum, with involvement of the sacral neural foramina and spinal canal and extension into the presacral space.

GIANT CELL TUMOR

Axial T1-weighted MR image shows an area of low signal intensity in the mass, a finding that indicates penetration into the bone marrow. The spinal canal is markedly narrowed, and the left sacroiliac joint is irregular.

ANEURYSMAL BONE CYSTANEURYSMAL BONE CYST

Blood filled expansile masses.Blood filled expansile masses. Most are manifested in first two decades of Most are manifested in first two decades of

life ,more commonly in second decade.life ,more commonly in second decade. 20% of these tumours arise from vertebral 20% of these tumours arise from vertebral

column ,among these 20% arise from posteror column ,among these 20% arise from posteror elements of sacrum.elements of sacrum.

Classically they appear as multiple blood filled Classically they appear as multiple blood filled spaces seperated by septa.spaces seperated by septa.

In contrast to giant cell tumours ,these tumours In contrast to giant cell tumours ,these tumours are delimited by a thin rim of bone.are delimited by a thin rim of bone.


Both CT and MRI are usefull for Both CT and MRI are usefull for depicting the lesion.depicting the lesion.

CT and MRI display fluid –fluid levels CT and MRI display fluid –fluid levels representing hemorrhages which is representing hemorrhages which is charecteristics.charecteristics.

ANEURYSMAL BONE CYST

Anteroposterior pelvic radiograph demonstrates distortion of the sacrum (arrows).

ANEURYSMAL BONE CYST

Axial CT scan obtained with intravenous contrast material at the level of the inferior sacrum shows an expansile osteolytic mass (arrows) with cortical destruction, involvement of the sacral spinal canal, and disruption of the left sacroiliac joint.

OSTEOBLASTOMA AND OSTEOBLASTOMA AND OSTEOD OSTEOMA OSTEOD OSTEOMA

These very rarely occur in sacrum and These very rarely occur in sacrum and usually involve posterior elements.usually involve posterior elements.

Because of similar histopathological Because of similar histopathological features ,they are considered variants.features ,they are considered variants.

Rarely osteoblastoma show cortical Rarely osteoblastoma show cortical destruction and extension to adjacent destruction and extension to adjacent tissues.tissues.

However presacral extension is very However presacral extension is very unusual.unusual.

OSTEOBLASTOMA

Sagittal T2-weighted MR image of the pelvis shows the origin of the heterogeneous presacral mass in the distal sacrum.

CHORDOMACHORDOMA

These are the most common primary sacral These are the most common primary sacral neoplasms.neoplasms.

They accont for 2-4% of primary bone They accont for 2-4% of primary bone tumours.tumours.

50% arise in sacrococcygeal region.50% arise in sacrococcygeal region. Upto 60% of chodomas in sc region appear Upto 60% of chodomas in sc region appear

as midline lytic lesions often with as midline lytic lesions often with calcifications.calcifications.

This type usually includes a presacral This type usually includes a presacral component and involves iliac bones.component and involves iliac bones.


On T1 weighted MRI they show low to On T1 weighted MRI they show low to intermediate signal intensity.intermediate signal intensity.

On T2 weighted images they show On T2 weighted images they show significantly increased signal intensity significantly increased signal intensity and variable contrast enhancement.and variable contrast enhancement.

CHORDOMA

Axial CT scan obtained with intravenous contrast material at the level of the middle sacrum shows an expansile soft-tissue mass with calcifications (arrows), cortical destruction, extension into the presacral space, and involvement of the epidural space of the sacral spinal canal.

OSTEOGENIC SARCOMA.OSTEOGENIC SARCOMA.

They are the most frequent primary They are the most frequent primary malignant bone tumour.malignant bone tumour.

Spinal involvement in less than 3%.Spinal involvement in less than 3%. Two thirds are in lumbosacral region.Two thirds are in lumbosacral region. They may occur after radiation They may occur after radiation

therapy.therapy.


They appear as lytic ,osteoblastic or They appear as lytic ,osteoblastic or mixed types on radiographs and CT mixed types on radiographs and CT scans.scans.

CT depicts extension into CT depicts extension into paravertebral region and spinal canal.paravertebral region and spinal canal.

On MRI low intensity on T1 and high On MRI low intensity on T1 and high intensity in T2 weighted images.intensity in T2 weighted images.

OSTEOGENIC SARCOMA

Axial unenhanced CT scan shows a predominantly sclerotic sacrum with indistinct anterior margins.

OSTEOGENIC SARCOMA

Axial T1-weighted MR image at the level of the middle sacrum shows replacement of the bone marrow of the right sacral ala and body by a low-signal-intensity mass. The tumor extends anteriorly to efface the fat plane adjacent to the right psoas muscle and presacral space (arrows). The right sacroiliac joint is indistinct, but there is no evident involvement of the right iliac bone or spinal canal.

EWINGS SARCOMA.EWINGS SARCOMA.

Ewings sarcoma ,extraosseous Ewings sarcoma ,extraosseous ewings sacoma and PNET belong ewings sacoma and PNET belong same family of round cell tumours.same family of round cell tumours.

Present in first three decades of life.Present in first three decades of life. 3-10% originate in spine,metastatic 3-10% originate in spine,metastatic

involvement is more common.involvement is more common. Lumbosacral region is the most Lumbosacral region is the most

common site of origin.common site of origin.

EWINGS SARCOMAEWINGS SARCOMA

These typically fill marrow cavity,destroy These typically fill marrow cavity,destroy cortex and produce a soft tissue mass that cortex and produce a soft tissue mass that is usually larger than bony component.is usually larger than bony component.


Radiography and CT show lytic,sclerotic Radiography and CT show lytic,sclerotic and mixed features.and mixed features.

MRI clearly depicts both intra and MRI clearly depicts both intra and extraosseous components of the tumour extraosseous components of the tumour including paraspinal ,extra dural and including paraspinal ,extra dural and presacral involvement.presacral involvement.

Exraosseuos part is usually the Exraosseuos part is usually the predominant component of the tumour and predominant component of the tumour and may include thin fibrous septa.may include thin fibrous septa.

EWING SARCOMA

Axial pelvic CT scan obtained with intravenous contrast material in a 15- year-old girl with back and bilateral hip pain shows destruction of the lower sacrum by a mass with a significant soft-tissue component. The mass has extended into the presacral space dorsal to the sacrum, displaced the uterus (U) and bladder (B) anteriorly, and obliterated the neural foramina.

EWING SARCOMA

Axial pelvic CT scan obtained with intravenous contrast material in a 14-year-old girl with hip pain shows an enhanced soft-tissue mass that has displaced the rectum (white arrow) and invaded a sacral foramen (black arrow).

EWING SARCOMA

Sagittal T2-weighted MR image demonstrates a heterogeneous presacral mass with extension posterior to the sacrum (arrow).

OTHER MASSES

Hematoma Extension or metastasis to the

presacral space from another site

PRESACRAL MASS

Sagittal contrast-enhanced T1-weighted fat-saturated MR image

PRESACRAL MASS

A homogeneous presacral mass (arrows) with persistent high signal intensity despite fat saturation in b, a finding indicative of a hematoma.

CONCLUSIONS

The presacral space is a complex anatomic region that may be affected by a wide variety of masses

CT and MR imaging play a central role in the evaluation of primary lesions that occur in this region.

Knowledge of the normal anatomy and familiarity with the imaging features and clinical manifestations of these lesions are important for determining the type of mass or narrowing the differential diagnosis, as well as for defining the extent of the mass, and especially important for surgical consideration.

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Imaging Presacral Masses