148 Skull tumour & GB 21.4 skull tumors

Greenberg,Handbook of neurosurgery 21.4 Skull Tumors

Youmans,Neurological surgery Chapter 148 Skull Tumors

Osborn,Expert ddx in brain&spine

Skull tumors

Outline

OsteomaHemangiomaDermoid and

epidermoid tumors

Chondroma (osteochondroma)MeningiomaAneurysmal bone

cyst

Malignant tumorsBone metastases to the skullChondrosarcomaOsteogenic sarcomaFibrosarcoma

Benign tumorsNon-neoplastic skull lesion

Paget's disease of the skull

Langerhans Cell Histiocytosis

(Histiocytosis X)Fibrous dysplasiaHyperostosis

frontalis internaSinus pericranii

Benign tumorsOsteomaHemangiomaDermoid and epidermoid tumorsChondroma(osteochondroma)MeningiomaAneurysmal bone cyst


OsteomaThe most common primary bone tumor of

the calvariaBenign,slow-growing lesionsOccur commonly in the cranial vault,

mastoid and paranasalair sinuses, and the mandible

• Common in females, highest incidence is in 6th decade

• Pathology : Consists of osteoid tissue within osteoblastic tissue, surrounded by reactive bone Greenberg,Handbook of neurosurgery 21.4 Skull Tumors

OsteomaSkull x-ray

Round, sclerotic, well demarcated, homogeneous dense projection.

Usually arise from outer table of skull (inner table less common).

May be compact or spongy(spongy osteoma may be radiolucent)

Unlike meningiomas, diploe are preserved and vascular channels are not increased.

Treatment Asymptomatic lesions may simply be followed.Surgery may be considered for cosmetic reasons,

or if pressure on adjacent tissues produces discomfort.



7% of skull tumorsTwo types: cavernous (most common) and

capillary(rare)

X-rayCharacteristically shows a circular lucency

with honeycomb or trabecular pattern (50% of cases) or radial trabeculations producing a sunburst pattern (11% of cases)

Sclerotic margins are evident in only ... 33%.CT: hypodense lesion with sclerotic spaced

trabeculations. NonenhancingBone scan: typically hot.

Hemangioma


HemangiomaTreatment

Accessible lesions may be cured by en bloc excision or curettage.

The gross appearances of a hard, blue-domed mass beneath the pericranium.

Radiation may be considered for inaccessible tumors



RareUsually midlineArise within the diploe and expand both

inner and outer tablesThese benign lesions may involve

underlying dural venous structures or brain

Dermoid and epidermoid tumor


Dermoid and epidermoid tumorX-ray

Osteolytic lesions have well-defined, sclerotic margins

CT : hypodense (keratin contains fats), non-enhancing

MRI : like CSF, they are low intensity on T1 WI and high signal on T2WI, but unlike CSF they are high signal on DWI MRI

TreatmentSurgicalSearch must be made for a tract leading to

the intracranial cavity which must be followed if foundGreenberg,Handbook of neurosurgery 21.4 Skull Tumors


Chondroma(Osteochondroma)Arise form ectopic hyaline cartilaginous rest

trapped within suture lineCommon : skull base,anterior to pon ,sphenoid

bone, boardering of foramen lacerum

CT Well-demarcated, off midline, lobulated, contrast-

enhancing, dense mass contiginous with the underlying bone and marked by popcorn calcification

MRIThin cartilaginous cap overlying the dense osseous

core


Chondroma(Osteochondroma)Treatment

Complete resection,including cartilaginous capsule


MeningiomaIntraosseous(intradiploic) meningioma are

uncommonPrimary intraosseous meningiomas do not

involve the inner or outer tables of the skull or the dura

“ectopic meningiomas” or “primary extradural meningiomas”

Arise from rests of arachnoid cap cells trapped within sutures at birth and during molding of the head


MeningiomaPlain radiograph and CT

Hyperostosis(some are lytic or both lytic and sclerotic)Expansion of the diploë, with the inner and outer

tables of the skull separated and thinned over the biconvex mass

MRITW1 : hypointense, TW2 : hyperintenseHomogeneous contrast enhancement on both CT and

MRI

Treatment En bloc resection with margin



Aneurysmal bone cystRareSecondary to trauma to be caused by a

circulatory disturbance resulting in venous hypertension and venous pooling within the bone

A typical finding : local swelling and tenderness of a few month duration

Gross : vascular channel that give them spongy-like appearance

Histologic : communicating pools of venous blood without endothelium in a thin matrix of fibro-osseous strands along with frequent multinucleate giant cells.Youmans,Neurological surgery Chapter 148 Skull Tumors

Aneurysmal bone cystImaging

LyticLoculated lesion with fluid-fluid levels

caused by layering of blood products within internal cavities

The lesion typically begins in the diploë, and expansion or “blowout” of the inner and outer cortices

TreatmentGross total resection


Malignant tumorsBone metastases to the skull

1. prostate2. breast3. lung4. kidney5. thyroid6. lymphoma7. multiple myeloma/plasmacytoma

ChondrosarcomaOsteogenic sarcomaFibrosarcoma


Bone metastasis to skullMost common : breast, lung, and prostateUncommon : renal and thyroid carcinoma Cranila vault more than skull base

RadiographicLytic lesion except prostate cause sclerotic

lesionMRI : T1W : hypointense with variable T2W

characteristic and variable contrast enhancement

Radionuclide bone scanning : sensitive method for detecting skull metastasis


Bone metastasis to skullCSF

Helpful in suspected metastasis to the skull base

If CSF is normal, metastasis is more likely than infection to be the cause of multiple cranial neuropathies

A CSF study may also reveal the presence of meningeal carcinomatosis


Bone metastasis to skullTreatment

Patients with skull metastases are frequently at an advanced stage of their primary disease and often asymptomatic : Surgery may not be required for diagnostic or even therapeutic purposes

Symptomatic or palpable skull mass may be the first sign of the underlying cancer : surgical resection may be helpful or FNA in multiple or too indolent to need resection




ChondrosarcomaRare,malignant neoplasm of cartilageFound away from midline with cranial

neuropathies(particularly abducen neuropathy)

Skull : painless expanding massSubtype

Myxoid(conventional low grade) most common

DedifferentiatedMesenchymal

Pathologyhypercellular with hyperchromatic and

pleomorphic nucleiYoumans,Neurological surgery Chapter 148 Skull Tumors

ChondrosarcomaCT

Calcifications and ossifications within the tumor mass

MRILobulated lesions that appear isointense to

hypointense on T1-weighted images and hyperintense on T2-weighted images

Show heterogeneous contrast enhancement

TreatmentSurgical resection with adjuvant therapy



Osteogenic sarcomaMost common malignanat tumor in bone

but it is relatively rare in skullCranial vault than skull baseSecondary to radiationPatients with tumors attaining large size or

involving the skull base may complain of local tenderness, headaches, proptosis, ophthalmoplegia, facial weakness, decreasedhearing ability, or tinnitus

The alkaline phosphatase level may be a useful diagnostic test


Osteogenic sarcomaPathology

Sarcomatous spindle cell stroma with an associated osseous component

CTBony destruction, cortical expansion, and

a “sunburst” periosteal reactionDemonstrate areas of irregular calcification,

as well as low-attenuation areas representing necrosis

MRIheterogeneous signal on both T1- and T2-

weightedTreatment

Gross total resectionYoumans,Neurological surgery Chapter 148 Skull Tumors

FibrosarcomaRareMay arise from degeneration of a

preexisting lesion such as a fibroma from Paget’s disease or it may occur after radiation treatment

Typically indolent, asymptomatic massesType : low grade (most differentiated),

moderately differentiated, and poorly differentiated

Pathology interlaced bundles of spindle cells and

collagen fibers in a “herringbone” patternYoumans,Neurological surgery Chapter 148 Skull Tumors

FibrosarcomaRadiographic

Lytic lesion with cortical destruction or expansion, or both, and soft tissue extension

Radiolucent

TreatmentEn bloc resection


Non-neoplastic skull lesionPaget's disease of the skullLangerhans Cell Histiocytosis(Histiocytosis

X)Fibrous dysplasiaHyperostosis frontalis internaSinus pericranii


Paget’s disease of the skull(Osteitis Deformans)Disorder characterized by the uncoupling of

bone formation and resorption, with resultant bone thickening and weakening

ClinicalHeadache, cranial neuropathy, EDH fron trauma

CTAreas of sclerosis mix with the preexisting lytic

areas, and a mottled “cotton wool” appearance develops

MRImixed intensity


Paget’s disease of the skull(Osteitis Deformans)The most common types of sarcomatous

degeneration are to osteosarcoma (50% to 60% of instances) and fibrosarcoma (20% to 25% of instances)

TreatmentMedical : bisphosphonates or calcitonin is the

first line


Paget’s disease Fibrous dysplasia

Symmetrical Unilateral

Thickening of inner cortex

Cortical destruction

Cotton wool Groud grass apperance

Older thane fibrous dysplasia

Involve orbit,paranasal sinus, sphenoid bone

Paget’s disease of the skull(Osteitis Deformans)


Paget’s disease of the skull(Osteitis Deformans)


Fibrous dysplasiaBenign condition in which normal bone is

replaced by fibrous connective tissueMost common : rib or craniofacial bone esp

maxillaPattern

Monostotic: most common Polyostotic: 25% with this form have> 50% of

the skeleton involved with associated fractures and skeletal deformities

as part of McCune-Albright syndromeAutonomous endocrine hormone excess, such as in

precocious pubertyPolyostotic fibrous dysplasiaUnilateral café au lait spots


https://en.wikipedia.org/wiki/Endocrine

https://en.wikipedia.org/wiki/Precocious_puberty

https://en.wikipedia.org/wiki/Polyostotic_fibrous_dysplasia

https://en.wikipedia.org/wiki/Polyostotic_fibrous_dysplasia

https://en.wikipedia.org/wiki/Caf%C3%A9_au_lait_spot



Fibrous dysplasiaClinical

incidental findinglocal pain and swelling or deformity may predispose to pathologic fractures when they

occur in long bones cranial nerve involvementseizures serum alkaline phosphatase is elevated in about

33%, calcium levels are normal darkened hair pigmentation overlying skull lesions spontaneous scalp hemorrhages rarely associated with Cushing's syndrome


Fibrous dysplasiaGroud glass appearance on x-ray due to

the thin spicules of woven bone

TreatmentNo cure for fibrous dysplasiaLocal procedures (mostly orthopedic) are

used for deformities or bone pain that is refractory to other treatment

Neurosurgical involvement may be required for skull lesions producing refractory pain or neurologic symptoms

Calcitonin may be used for widespread lesions with bone pain and/or high serum alkaline phosphatase levels


Fibrous dysplasia


Fibrous dysplasia


Langerhans cell Histiocytosis(Histiocytosis X)Group of related disorders of abnormal

uncontrolled histiocyte proliferation: Eosinophilic granulomaHand-Schüller-Christian diseaseAbt-Letterer-Siwe diseaseHashimoto-Pritzker disease

Predominantly occurs in children and adolescents, with the mean age at incidence being 12 years

ClinicalSolitary mass with localized pain


Langerhans cell Histiocytosis(Histiocytosis X)Pathology

Clonal proliferation of S-100–positive histiocytic cells in clusters mixed with inflammatory cells, which are predominantly eosinophils.

CD1a antigen EM : racquet-shaped Birbeck’s granules

X-rayClassic punched-out lytic border without a

sclerotic boarderBevel appearance : bony destruction outer

table than inner tableExtraosseous contrast-enhancing soft tissue

mass


Langerhans cell Histiocytosis(Histiocytosis X)Treatment

surgery radiation therapy chemotherapyimmunotherapy


Langerhans cell Histiocytosis(Histiocytosis X)


Hyperostosis Frontalis InternaBenign irregular nodular thickening of the

inner table of the frontal bone that is almost always bilateral

More common in womenClinical

Incidental finding, headache, cranial defectX-ray

Thickening of the frontal bone with characteristic sparing of the midline

TreatmentRemoval of thickening bone


Hyperostosis Frontalis InternaMetabolic craniopathy

Morgagni's syndrome (AKA Morgagni-Stewart-Morel syndrome)headache, obesity, virilism and neuropsychiatric

disorders (including mental retardation) Endocrinologic abnormalities

Acromegalyhyperprolactinemia

Metabolichyperphosphatemia obesity diffuse idiopathic skeletal hyperostosis (DISH

Diffuse idiopathic skeletal hyperostosis (DISH) Greenberg,Handbook of neurosurgery 21.4 Skull Tumors

Hyperostosis Frontalis Interna

Sinus pericraniiAbnormal collection of veins adherent to

the outer table of the skull in communication with the intracranial venous sinuses via dilated diploic and emissary veins of the skull

Cause : congenital, spontaneous, traumaLocated in midlineThe lesion is nonpulsatile, expands with a

Valsalva maneuver or while the patient is supine, and decreases with head elevation or direct compression

Histology : a tangle of nonmuscular venous vessel Youmans,Neurological surgery Chapter 148 Skull Tumors

Sinus pericraniiX-ray

Radiolucent due to skull defectCT

Extraosseous soft tissue mass, as well as an emissary channel through the skull, with smooth erosion of the bone’s outer table

CT with contrast show venous fillingMRI

Hypointense on T1 and hyperintense on T2Treatment

Progressive or symptomatic lesionSurgical resection

Sinus pericranii

Health & Medicine

148 Skull tumour & GB 21.4 skull tumors