Objective:

To present an interesting case and potential pitfalls in diagnosing neurosarcoidosis.

Background:

Isolated neurosarcoidosis is challenging to diagnose, with less than 1% of sarcoidosis cases presenting without evidence of systemic disease. Histologic examination is required to meet criteria for diagnosis of “definite” neurosarcoidosis, but biopsies are often not feasible in high-risk functional areas of the nervous system.

Design/Methods:

N/A

Results:

A 48-year-old male with a history of anxiety presented with a two-month history of proximal bilateral lower extremity weakness and truncal paresthesias. MR imaging of the brain was nondiagnostic. Spine imaging showed longitudinally extensive transverse myelitis extending from C3 to T2 and an adjacent contrast-enhancing intradural mass. Infectious workup was unremarkable. Though deferred initially due to spinal cord edema, after a course of steroids a lumbar puncture was obtained. CSF abnormalities were nonspecific with pleocytosis and elevated protein levels. Antibody assays for NMO and MOGAD were negative. Pan-CT imaging and lab work found no evidence of a primary malignancy. A PET CT was obtained and demonstrated FDG uptake in the spinal cord, as well as mediastinal/hilar lymph node involvement consistent with sarcoidosis. The patient has subsequently been doing well on steroids and infliximab.

Conclusions:

Meeting clinical criteria to diagnosis neurosarcoidosis is often challenging. We present a patient with steroid-responsive transverse myelitis diagnosed with suspected isolated spinal neurosarcoidosis. Workup for alternate diagnoses, including autoimmune, infectious, and neoplastic causes was unremarkable. His clinical picture was suggestive of sarcoidosis, however given the location of disease, biopsy was not feasible. Ultimately, CT PET imaging was consistent with sarcoidosis and showed evidence of occult pulmonary involvement. The case highlights the utility of CT PET imaging as a diagnostic tool in settings where biopsy is not feasible and/or conventional CT imaging is non-diagnostic. Physicians should be aware of benefits of PET imaging in diagnosing atypical neurosarcoidosis.