Longitudinally extensive myelitis as first presentation of renal cell carcinoma.

Abstract not available.

Longitudinally extensive myelitis (LETM) is spinal cord inflammation involving three or more vertebral segments. The most common cause of LETM is neuromyelitis optica spectrum disorders (NMOSD) and other inflammatory demyelinative disease. Neuromelitis optica (NMO) is a demyelinating syndrome of the nervous system by attacks of optic neuritis and myelitis. Intramedullary tumors such as astrocytoma, ependymoma, and intravascular lymphoma are other causes of LETM, and intramedullary metastasis is very rare. However, development of progressive myelopathy in the absence of antecedent neurological symptoms and without signs indicating dissemination beyond the spinal cord is a diagnostic challenge, and rule out of other causes of myelitis should be done. 1 There have been many reports of patients with demyelinating disorders mimicking spinal cord tumors, 2-5 and on the contrary, we report a rare case of renal cell carcinoma (RCC) presenting by LETM without manifestation of primary tumor.
A 70-year-old farmer without any other medical history was referred in October 2014 with right hand paresthesia and neck pain that radiated to shoulders.
The first cervical magnetic resonance imaging (MRI) showed cervical spondylosis without abnormality in spinal cord parenchyma. The patient was treated for cervical spondylosis.
Two months later he noticed atrophy of first interosseous muscle and brain MRI was performed, which revealed a few small vessel ischemia and electromyography study showed motor neuron disease.
In May 2015, he was referred to our hospital with paraparesis (left more than right). At physical examination, mental examination was normal and paraparesis with a motor grade 3/5 in left and 4/5 in right side was detected without sphincteric problem.
The patient underwent whole spine MRI, which revealed an extensive intramedullary hyperintensity in T2-weighted MRI involving predominantly central spinal cord and extended until medulla location (Figure 1, A).
Routine investigations including hematology, , echocardiography, and chest X-ray showed no abnormality. The patient complained of dyspnea. LETM due to inflammatory demyelinated and primary spinal cord tumor were main differential diagnosis. High-dose methyl prednisolone was started and weakness and dyspnea was recovered dramatically after 5 days of treatment. Serum sample was referred for vasculitis tests and NMO antibody. Brain and cervical MRI with gadolinium and computed tomography (CT) scan of thorax and abdomen with contrast was done. After discontinue of corticosteroid, motor function in both lower extremities deteriorated without sphincter problem.
The second MRI of the cervical spine revealed an ill-defined T1 sequence isointense and T2 hyperintense intramedullary lesion extending from medulla to T2 levels with cord enlargement. There were two lesion enhancements (Figure 1, B-C). Abdominal CT scan showed large renal cell mass (Figure 1, D), and serum NMO-IgG was negative. However, the neurological features were highly suggestive of intramedullary lesion secondary to RCC. Radiotherapy was recommended by oncologist. After two weeks, before beginning treatment, the patient admitted for sign of sever hematuria and acute renal failure and unfortunately died of complications.
LETM is one of the common presentations of NMOSD. MRI of the spine is very helpful in diagnosing NMOSD. In acute phase, it typically shows LETM and gadolinium enhancement; in chronic stage, the enhancement and expansion resolve while the T2 signal persists, but the LETM regresses to less than three segments and breaks up in to shorter fragments. 1 Many neoplastic lesions are misdiagnosis as intramedullary spinal cord myelitis such as NMOSD. More specifically, the fallowing misdiagnoses are made: infectious disorders, demyelination [multiple sclerosis (MS) and NMOSD], granulomatous disease, vascular lesions, and syringomyelia.