section name header

Information

Skull and Spine Disorders

Frequency: 90% of all spinal cord + vertebral neoplasms

Intramedullary Metastasis!!navigator!!

Prevalence: 0.9–2.1% of CNS metastases (autoptic)

Origin: lung (40–85%), breast (11%), melanoma (5%), renal cell (4%), colorectal (3%), lymphoma (3%), cerebellar medulloblastoma; 5% of unknown origin

Spread:

  1. common: hematogenous (via arterial supply) / direct extension from leptomeninges
  2. rare: dissemination along central canal / extension along Batson venous plexus from retroperitoneal primary tumor / extension along perineural lymphatic ducts
  • symptomatic for <1 month (in 75%):
    • motor weakness, bowel / bladder dysfunction (60%)
    • pain (70%), paresthesia (50%)

Location: cervical (45%), thoracic (35%), lumbar cord (8%)

Myelography (up to 40% undetected)

MR:

  • mild cord expansion over several segments (average length of 2–3 vertebral segments)
  • central area of low SI (mimicking syrinx) on T1WI
  • high SI on T2WI ← edema / tumor infiltration
  • intense homogeneous enhancement
  • disproportionately large amount of surrounding edema

Prognosis: 66% die within 6 months

Rx: radiation therapy, corticosteroids

Extradural / Epidural Metastasis!!navigator!!

Origin: breast (22%), lung (15%), lymphoma (10%), prostate (10%), kidney (7%), gastrointestinal (5%), melanoma (4%)

DDx: schwannoma, neurofibroma, cysts

Intradural Metastasis!!navigator!!

= MENINGEAL CARCINOMATOSIS OF SPINE

  • round multifocal masses varying substantially in size from a few mm to >10 mm
  • enlarged cord (from diffuse tumor coating of spinal cord) simulating an intramedullary lesion
  • thickening of meninges (especially in lymphoma, breast cancer, prostate cancer)
  • thickened + nodular matted nerve roots
  • nodular + irregularly narrowed thecal sac
  • Gd-DTPA enhancement (difficult to detect due to adjacent fat + enhancing epidural venous plexus)

Dx: CSF analysis (more sensitive than imaging)

DDx: moderate to severe meningitis, benign postoperative arachnoiditis, neurofibromatosis

Metastases from Outside CNS

  1. with subarachnoid hemorrhage:
    • bronchogenic carcinoma, malignant melanoma, choriocarcinoma, hypernephroma
  2. others: breast (most common), lymphoma
    • predominantly dorsal location

Drop Metastases

= CSF SEEDING OF INTRACRANIAL NEOPLASMS

Age: occurs more frequently in pediatric age group than in adults

Location: lumbosacral + dorsal thoracic spine ← CSF flow / gravitation)

Site: on spinal arachnoid / pia mater

CNS tumors causing drop metastases:

  1. Primitive neuroectodermal tumor
  2. Medulloblastoma: up to 33%
  3. Anaplastic glioma
  4. Ependymoma: after local recurrence, more common in infra- than supratentorial ependymomas
  5. Germinoma
  6. Pineoblastoma, pineocytoma

Less common: choroid plexus carcinoma, teratoma, angioblastic meningioma

mnemonic: MEGO TP

  • Medulloblastoma
  • Ependymoma
  • Glioblastoma multiforme
  • Oligodendroglioma
  • Teratoma
  • Pineoblastoma, PNET

Outline