Isolated spinal neurosarcoidosis: An enigmatic intramedullary spinal cord pathology-case report and review of the literature
A 44-year-old African American man presented at an outside hospital with history of neck pain and left arm pain in a nondermatomal distribution associated with left hand numbness/tingling and left-sided weakness for a couple of months. Examination revealed presence of subtle left sided hemiparesis (4+/5 on Medical Research Council (MRC) grade) and considering a diagnosis of cervical spondylosis, a plain MRI of cervical spine was ordered which revealed presence of moderate cervical stenosis associated with T2 signal changes with no significant focal compression and he was treated conservatively. He however had progression of symptoms over the next few weeks due to which he was referred to our institution. Examination revealed presence of worsening weakness involving the left side (3/5) with brisk reflexes in bilateral upper and lower extremities. Sensory exam showed no gross dermatomal sensory deficits with presence of Hoffman's reflex. These neurologic findings prompted us to repeat an MRI with contrast enhancement due to presence of signal changes on the MRI without significant compression and disconcordance between clinical examination and imaging findings. MRI revealed presence of an approximately 1.5 cm patchy enhancement involving the left half of the cervical spinal cord at C4 level with presence of T2 signal changes spanning three to four segments in the cervical spine along with presence of moderate to severe spinal canal stenosis [Figures and ]. In light of the clinical symptoms and neuroimaging abnormalities, the diagnosis of spondylotic compressive myelopathy was questioned and a differential diagnosis of a neoplasm (astrocytoma/ependymoma), inflammatory, ischemic, and demyelinating lesions was entertained. Initial laboratory workup including lumbar puncture revealed that the patient had a mildly elevated protein level (43.5 mg/dl), a normal immunoglobulin (Ig)G/albumin CSF ratio (0.2), negative oligoclonal bands, and no malignant cells on CSF cytology studies. His CSF also demonstrated 110 red blood cells and 15 white blood cells per ml with 90% lymphocytes. Quantiferon gold tuberculosis (TB) test, aerobic, anaerobic, fungal, and TB cultures were all negative making infection an unlikely diagnosis. Erythrocyte sedimentation rate and C-reactive protein were slightly elevated with values being 19 (N: 0-17 mm/h) and 17 (N: 0.0-8 mg/dl). He was started on pulse dose of steroids with a likely diagnosis of myelitis and his clinical examination improved with improvement in motor strength to 4+/5 and he could ambulate better. However, while the steroids were being tapered, he had recurrence of symptoms with worsening weakness (3/5). The steroids were restarted, but because it was not possible to make a definitive diagnosis based on laboratory studies, in the face of neurological worsening on tapering steroids, despite the risks of an intramedullary biopsy, this was thought to be the best option for diagnosis. A C3 through C6 laminoplasty and excisional biopsy of the C4 intramedullary lesion was performed to address the cervical stenosis and biopsy the intramedullary lesion []. Intraoperatively, the cord appeared normal except that it was quite swollen laterally on the left-hand side at C4 level and a dorsal root entry zone myelotomy was performed and abnormal tissue was immediately encountered which was quite distinct from the normal spinal cord tissue. This was sent for frozen section, which revealed gliosis versus neoplasm. Given the fact that this could be neoplastic tissue, further dissection was then carried out and a dissectible plane was found separate from normal spinal cord and a gross total resection could be achieved. The patient initially had worsening of his strength on left side and became essentially hemiplegic, but started improving gradually. Final pathology demonstrated non-necrotizing granulomatous disease consistent with sarcoidosis []. After the diagnosis was confirmed, an MRI of the brain [] and CT of the chest abdomen and pelvis were done to rule out any other site of involvement which demonstrated slightly, but nonsignificant mediastinal and retroperitoneal lymph nodes. Serum and CSF angiotensin converting enzyme (ACE) levels performed were within normal limits. He was subsequently treated with pulse dose of intravenous (IV) methylprednisolone, methotrexate, and induction infliximab (chimeric monoclonal antibody against tumor necrosis factor (TNF)-α) therapy and was discharged home with significant improvement in his motor strength. He remained in clinical follow-up with rheumatologist and neurologist and was treated on an outpatient basis with prednisolone 60 mg/day for 6 months along with methotrexate and infliximab. At his last follow-up at 9 months, he was on tapering dose of prednisone with continued weekly oral methotrexate and eight weekly maintenance infliximab therapy. He maintained neurological improvement in his motor strength except residual left ankle dorsiflexion weakness required an ankle foot orthosis and could ambulate independently with occasional use of walker for stability.