“Not another one!” Making sense of CT and MR imaging features of focal splenic masses

Sara Smolinski1 MD, Michael Morrow1 DO, Qiqing Ge1 MD, Shirley McCarthy2 MD, Alena Kreychman1 MD, and Dmitry Rakita1 MD 1Baystate Medical Center, 2Yale New Haven Hospital

References 1. Abbot RM, et al. Primary Vascular Neoplasms of the Spleen: Radiologic-Pathologic Correlation. Radiographics 2004; 24:1137-1163.

2. Ahmed S, et al. Splenic Incidentalomas. Radiol Clin N Am. 2011;49: 323-47.

3. Ekeh AP, et al. The prevalence of incidental findings on abdominal computed tomography scans of trauma patients. J Emerg Med 2010;38(4):484–9.

4. Lam KY et al. Metastatic tumors of the spleen. A 25-year clinicopathologic study. Arch Pathol Lab Med. 2000; 124:526-530.

5. Levy AD, et al. Littoral cell angioma of the spleen: CT features with clinicopathologic comparison. Radiology 2004; 230:485–490.

6. Luna A, Ribes R, et al. MRI of Focal Splenic Lesions Without and With Dynamic Gadolinium Enhancement. AJR 2006; 186:1533-1547.

7. Paluska TR, et al. Incidental CT findings in trauma patients: incidence and implications for care of the injured. J Trauma 2007;62:157–61.

8. Warshauer DM, et al . Imaging Manifestations of Abdominal Sarcoidosis. AJR 2004; 182:15-28.

The majority of splenic lesions are incidentally detected on routine abdominal CT, typically

performed for other indications. In an emergency room population being scanned for abdominal

pain or trauma, incidental splenic lesions were seen in approximately 1% of patients and the vast

majority of these were considered clinically benign.3,4 It is important to combine clinical factors

with imaging findings for the most accurate evaluation. Relevant findings include abdominal pain,

signs or symptoms of infection, immune status, history of malignancy, associated imaging

findings or history of abdominal trauma. In this poster, we review the most common splenic

lesions encountered and propose an algorithm for their diagnosis and management.

Incidental Splenic Lesions Splenic Cyst “True” congenital or parasitic cysts (20%) possess an epithelial lining. Pseudocysts (80%),

are posttraumatic without an epithelial lining. Typically asymptomatic, cysts may enlarge or

hemorrhage, causing pain or may be the sequela of prior trauma.1,2

images demonstrate a uniformly T2 hyperintense, non enhancing mass. The lesion was resected

for symptomatic relief. Histology demonstrated a congenital cyst with stratified squamous epithelial

wall.

Hemangioma Composed of a proliferation of vascular channels, ranging from capillary to cavernous. Most

commonly singular but may be multiple. Typically asymptomatic. Multiple hemangiomas are

associated with Klippel-Trenaunay-Weber syndrome or Kasabach-Merritt syndrome.1,2

Figure 2. 44 year old male with history of melanoma found to have an enhancing splenic

mass on a contrast enhanced staging CT (a). (b) SSFSE image demonstrates a T2

hyperintense mass. (c-e) T1 fat suppressed GRE images obtained pre, immediately and 1 minute

post contrast administration demonstrate a T1 hypointense mass with initial peripheral and

subsequent homogeneous enhancement, consistent with a splenic hemangioma. Follow up

imaging demonstrated one year stability.

Hamartoma Composed of a disorganized vascular channels and fibrotic red or white pulp elements. Most

are asymptomatic, although may present with pain, palpable mass or rupture if large.

Associated with tuberous sclerosis and Wiskott-Aldrich-like syndrome.1,2

upper abdominal pain. (a) SSFSE image demonstrates a homogeneous, mildly T2 hyperintense

splenic mass which creates a contour abnormality. (b) On the T1 GRE opposed phase image the

mass is isointense to the spleen (c-d) Multiphase subtraction post contrast GRE images

demonstrates progressive homogeneous enhancement. Interval growth of the mass led to

resection and a histological diagnosis of hamartoma.

Littoral Cell Angioma Rare vascular splenic neoplasm arising from littoral cells, which line the splenic red pulp

sinuses and are believed to play a role in the immune response. May be asymptomatic or

can present with abdominal pain, splenomegaly, anemia, thrombocytopenia and

constitutional symptoms. Typically benign but rare reports of malignant behavior, including

metastasis. May be solitary or numerous.1,2,6

mass isointense to normal splenic parenchyma. (b) Fat suppressed non contrast GRE image

demonstrates the mass to be hypointense to isointense to the spleen. (c) Multiphase post contrast

subtraction GRE images demonstrate initial hypointensity with progression to isointensity on the

equilibrium phase (d). Growth led to resection and a histological diagnosis of littoral cell angioma.

Infection

Lymphangioma

Sarcoidosis

Most commonly seen with concurrent hepatic abscesses and sepsis. Fungal microabscesses most common, in an

immunocompromised patient. Tuberculosis typically presents as coalescing micronodules or wedge shaped

peripheral septic emboli.1,2

a b c

Figure 7. 48 year old female with abdominal pain and fever. (a-b) Multiple

ill-defined T1 hypointense and T2 hyperintense intrasplenic and subcapsular

fluid collections consistent with abscesses. (c) CT imaging reveals multiple

subcapsular fluid collections with smaller intraparenchymal fluid collections. (d)

SSFSE image demonstrates a concurrent fluid collection in the liver. Fluid

aspirate grew Streptococcus intermedius.

Figure 8.

40 year old

immuno-

compromised

female with

fever and

abdominal pain.

Congenital abnormality of lymphatic tissue. May be capillary, cavernous or cystic. May be

solitary, scattered or diffuse. Typically asymptomatic, however may present with abdominal

pain, hemorrhage or thrombocytopenia.1,2

Lymphoma Most commonly presents as part of systemic disease, less commonly as primary splenic lymphoma. May present

as multiple nodules, heterogeneous infiltration or diffuse splenomegaly. Often with accompanying retroperitoneal

lymphadenopathy.2

Figure 11. 34 year old male

with pancytopenia. Contrast

enhanced CT demonstrates

diffuse enlargement and

heterogeneous attenuation of

the spleen. The patient

underwent splenectomy for

pain and thrombocytopenia.

Histology demonstrated

marginal zone lymphoma.

Figure 12. 56 year old

female with with

abdominal pain. Contrast

enhanced CT demonstrates

splenomegaly with

innumberable

hypoattenuating nodules

and retroperitoneal

lymphadenopathy. Lymph

node biopsy demonstrated

Hodgkin lymphoma.

Typically presents with multiple non-caseating granulomas on histology. Only 10% of patients present with solely

extra- pulmonary findings. May be associated with liver involvement and thoracic and abdominal lymphadenopathy.

Most patients with splenic involvement are asymptomatic, although hypercalcemia may be present. 2,5,8

a b c

Intense and heterogeneous enhancement

Heterogeneous Heterogeneous Angiosarcoma

Hypointense on immediate postcontrast images, occasionally rim-enhancing intense and heterogeneous enhancement

Hyperintense Hypo - Isointense

Metastases

Hypointense immediately after contrast administration, then isointense on delayed

Hypointense Isointense Lymphoma

Peripheral enhancement when encapsulated; septations may enhance

Hyperintense Hypo - Isointense

Infection

Minimal peripheral enhancement on delayed Hypointense Hypointense Sarcoidosis

Homogeneous progressive enhancement Variable Hypointense Littoral Cell Angioma

No internal enhancement; peripheral enhancement in cystic forms; progressive septal in cavernous and capillary forms

Hyperintense Hypointense Lymphangioma

Heterogeneously diffusely enhancing on early imaging, isointense or hyperintense on delayed

Hyperintense Isointense Hamartoma

Homogeneous brisk or progressive mottled enhancement

Hyperintense Hypointense Hemangioma

No enhancement Hyperintense Hypointense Cyst

Enhancement Pattern T2 T1 Pathology

Common MRI Characteristics Metastases

Only 3% of metastases are to the spleen. Occurs late in the disease, with concurrent involvement of other organs.

Most common sources are breast, lung, and melanoma.4

Figure 13. 60 year old

female with history of

breast cancer. Contrast

enhanced CT

demonstrates diffuse

hypoattenuating nodules

throughout the spleen.

Figure 14. 64 year old male with

history of lung cancer. Contrast

enhanced CT demonstrates

innumerable heterogeneous

hypoattenuating nodules throughout

the spleen and liver with an area of

necrosis in the largest splenic

metastasis.

a b c d

a b c d

a b c d

a b c d

b c d e a

circumscribed largely hypoattenuating mass in the anterior spleen. (b) SSFSE image

demonstrates a hyperintense mass with hypointense septae. (c) Noncontrast fat-suppressed GRE

image demonstrates a hypointense mass. (d) Septal enhancement is demonstrated on an image

obtained 5 minutes post contrast administration. Histology was consistent with lymphangioma.

(a) Innumerable hypoattenuating nodules throughout the spleen on a contrast enhanced CT. (b-c) SSFSE and fat

suppressed noncontrast GRE images demonstrate innumerable hypointense nodules. The nodules demonstrate mild

peripheral enhancement without internal enhancement, as seen on a post contrast axial GRE image (d) consistent with

sarcoid granuloma.

Splenic Mass(es) on CT

Symptoms +/-

Other organ involvement +/-

Abnormal lab values

Asymptomatic Pain attributable

to the spleen

Simple Cyst(s)

Differential, with typical clinical

findings:

- Sarcoidosis (Hypercalcemia)

- Lymphoma (Bulky lymphadenopathy)

- Infection (Sepsis)

- Metastases or metastatic primary

splenic angiosarcoma (Other organs)

Rarely symptomatic benign

neoplasms:

- Hamartoma

- Hemangioma

- Lymphangioma

- Littoral cell angioma

(All listed here may present with

thrombocytopenia or anemia, littoral

cell angioma may present with fever

and constitutional symptoms)

MRI

Indeterminate Solid Mass

Differential:

- Hamartoma

- Lymphangioma

- Littoral cell angioma

- Odds of asymptomatic

angiosarcoma

exceedingly small

Surgical consult,

MRI if further

characterization

warranted

Classic hemangioma

or hemorrhagic cyst

Imaging follow up in 6-12 months

to assess for growth

Differential:

- Lymphangioma

- Littoral cell angioma

- Large benign mass or cyst with

recent hemorrhage causing capsular

stretching

Differential:

- Pseudocyst

- Congenital cyst

- Echinococcus (very

rare, laboratory evidence)

No follow up imaging

No follow up imaging

Further imaging may

not be necessary

Figure 1. 14 year old female with

upper abdominal pain and a large

splenic cyst. (a) Contrast enhanced CT

demonstrates a fluid attenuation mass.

MRI performed 1 year later when patient

developed pain. (b-c) T2 fat-saturated

FSE and post contrast fat-saturated GRE

Figure 6. 55 year old

female with elevated

liver enzymes and a

history of sarcoidosis,

diagnosed by lymph

node biopsy

Angiosarcoma Consists of disorganized vascular channels. Rare and aggressive, presenting with diffuse metastasis to liver, lung,

bone, and lymphatic system. May present with abdominal pain, fever, fatigue, weight loss, anemia,

thrombocytopenia, or coagulopathy. High risk of spontaneous rupture.1,2,6

nodule in the spleen. Heterogeneity is consistent with internal

hemorrhage. (b) Fat suppressed non contrast GRE image

demonstrates a mixed signal intensity nodule in the spleen,

related to presence of internal hemorrhage. Two other similar

appearing nodules were noted in the spleen (not shown).

Figure 16. 43 year old

male with abdominal

pain and hypotension,

related to spontaneous

rupture of a metastatic

splenic angiosarcoma. a b Contrast enhanced CT image demonstrates

heterogeneous masses in the liver and spleen with

hemoperitoneum (Images courtesy of Barak

Friedman MD, NSLIJ, NY)

Figure 15. 81 year

old female with

epigastric pain. (a)

Fat suppressed T2

FSE demonstrates

a mixed signal

intensity exophytic

Figure 3. 46

year old

female with

ulcerative

colitis and

Figure 4. 48 year old

female with an

incidental splenic

mass on CT. (a)

Contrast enhanced

CT demonstrates a

Figure 5. 37 year old

female with history

of ulcerative colitis

and sclerosing

cholangitis. (a) SSFE

demonstrates a

Contrast enhanced CT

demonstrates numerous

hypoattenuating foci in the liver and

spleen, a typical imaging

presentation of fungal

microabscesses. Blood cultures

were positive for Candida albicans.

d