Combined intramedullary and intradural extramedullary spinal metastases in malignant melanoma.

Description A patient in their 30s presented with a 3-day history of lower back pain, lower limb weakness and new onset of urinary incontinence. The patient had a history of metastatic melanoma, including to brain, for which they had previously been treated with adjuvant chemotherapy and radiotherapy. Clinical exam revealed a palpable bladder at the umbilicus and reduced power in the lower limbs bilaterally. An MRI whole spine with gadolinium contrast agent revealed multiple enhancing lesions at the T5/6, T9 and T12–L3 levels, pronounced spinal cord oedema and a markedly distended bladder (figures 1 and 2). The location of these lesions within the spinal canal was mixed, including intramedullary metastases (ie, within the substance of the spinal cord) and intradural extramedullary metastases (ie, in the subarachnoid space but extrinsic to the cord). Lesions obliterated the cauda equina resulting in a cauda equina syndrome. The three possible locations for spinal metastases are intradural intramedullary, commonly shortened to intramedullary, intradural extramedullary and extradural (figure 3). To our knowledge, this is the first reported case of mixed intramedullary and intradural extramedullary spinal cord metastases from malignant melanoma. Spinal extradural metastases affect up to 10% of all patients with cancer.1 Intradural metastases are rare but as systemic therapy improves their incidence has been reported to be on the increase.2 Lung, brain and breast cancer metastases are among the most common.2 Images in...