Multiple Spinal Intramedullary Primitive Neuroectodermal Tumors Mimicking Acute Myelitis

BACKGROUND: Primitive neuroectodermal tumors (PNETs) are rare malignant neoplasms in the spinal cord that comprise undifferentiated or poorly differentiated neural crest cells. PNETs imaging findings lack specificity, making diagnosis difficult. CASE DESCRIPTION: A 16-year-old male patient presented with progressive weakness and numbness of the lower extremities for 1 month, which occurred after a cold. Significantly elevated protein levels were detected in his cerebrospinal fluid. Magnetic resonance imaging revealed multiple patchy or spindle-shaped hyperintensities on T2-weighted imaging, which is similar to acute myelitis imaging findings. However, the effect of hormone treatment was minimal. Enhanced magnetic resonance imaging with gadolinium-diethylenetriamine pentaacetic acid showed significant enhancement of intramedullary lesions and the meninges, which was diagnosed as tuberculosis and tuberculous meningitis. After therapy with quadruple antituberculosis treatment for 1 week, however, the T-spot was negative. Therefore, the antituberculosis regimen was ceased. Atypical cells were observed in cerebrospinal fluid from a third lumbar puncture. Next, most of the thoracic intramedullary lesions were resected. By histopathology, these lesions manifested as PNETs. CONCLUSIONS: This paper reports a very rare case of PNETs with multiple lesions in the spinal cord that mimicked acute myelitis and emphasizes that multiple PNETs lesions detected by magnetic resonance imaging could have an initial acute myelitis-like presentation, which should be considered a differential diagnosis.