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Neuroradiology Case of the Week
Case 320
Ashwani K. Sharma, MD and P-L Westesson, MD, PhD, DDS
Clinical
Presentation: A 45-year-old male, known case of metastatic melanoma, presented with fecal retention.
Imaging Findings: The present MRI shows signs of intrathecal drop metastasis seen as a thin longitudinal enhancement along the surface of the spinal cord in the cervical, thoracic and conus regions. There is also marked thickening of cauda equina nerve roots with nodular and diffuse enhancing components. These findings are suggestive of metastatic lesions.
MRI of the brain revealed hemorrhagic mass lesion, appearing hyperintense on T1 weighted images and having fluid fluid level.
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| Figure 1A-C: Axial T2, T1 and post-contrast T1 weighted images of brain reveal large mass lesion in the brain parenchyma appearing hyperintense on T1 and heterogeneously hypointense T2 weighted images and revealing contrast enhancement especially in its anterior aspect. Fluid fluid level is noted in the mass lesion suggesting bleed in it. |
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| Figure 2 A-D: Sagittal T2, axial T2, post-contrast T1 (lumbar and cervico-thoracic region) reveals nodular thickening of cauda equina and filum terminale with enhancement. Linear wavy enhancement is also noted both anterior and posterior to the spinal cord. Osseous components are unremarkable |
Diagnosis: Intradural metastases to spine and brain from metastatic melanoma
Discussion: The definitions used for spinal cord compression (SCC) have varied in different studies [1, 2]. Bayley, et al. [3] used a definition of "‘impingement of the subarachnoid space by metastatic tumor involving the vertebrae or bone fragments, or frank compression of cord or cauda equina". MRI of the spine is also essential for planning surgery or radiotherapy for SCC because of the better delineation of the extent of disease [4]. Spinal metastasis occurs in 10–60% of all carcinomas. The metastasis of systemic cancers usually occurs in the terminal phase of illness.
Five routes have been hypothesized for metastatic intradural spinal tumor from outside the central nervous system [5].
- Hematogenous via the arterial system
- Through the rich venous plexus
- Through perineural lymphatics
- Seeding from involved osseous structures to the cerebrospinal fluid through the dura mater
- Through an arterial embolism.
Radiologically basically four patterns of spread are noted, either solitary focal mass, or diffuse, thin, sheet-like coating of cord/roots, or rope like thickening of cauda or multifocal discrete nodules.
References:
- Talcott JA, Stomper PC, Drislane FW, Wen PY, Block CC, Humphrey CC, Lu C, Jolesz F. Assessing suspected spinal cord compression: a multidisciplinary outcomes analysis of 342 episodes. Support Care Cancer. 1999 Jan;7(1):31-8. [Medline]
- Lu C, Gonzalez RG, Jolesz FA, Wen PY, Talcott JA. Suspected spinal cord compression in cancer patients: a multidisciplinary risk assessment. J Support Oncol. 2005 Jul-Aug;3(4):305-12. [Medline]
- Bayley A, Milosevic M, Blend R, Logue J, Gospodarowicz M, Boxen I, Warde P, McLean M, Catton C, Catton P. A prospective study of factors predicting clinically occult spinal cord compression in patients with metastatic prostate carcinoma. Cancer. 2001 Jul 15;92(2):303-10. [Medline]
- Husband DJ, Grant KA, Romaniuk CS. MRI in the diagnosis and treatment of suspected malignant spinal cord compression. Br J Radiol. 2001 Jan;74(877):15-23. [Medline]
- Kubota M, Saeki N, Yamaura A, Iuchi T, Ohga M, Osato K. A rare case of metastatic renal cell carcinoma resembling a nerve sheath tumor of the cauda equina. J Clin Neurosci. 2004 Jun;11(5):530-2. [Medline]
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