An uncommon intramedullary tumor: primary spinal cord melanoma

Abstract

A 47-year-old woman was admitted with complaints of progressive weakness in the lower extremities and pain in the back and left leg. Thoracic magnetic resonance imaging (MRI) revealed a spinal intramedullary tumor between the T9 and L1 levels, which were iso- to hypointense on T2 and slightly hyperintense on T1-weighted images. The tumor was resected as total, and the diagnosis was malignant melanoma confirmed with histopathology. Neurological findings improved at the postoperative period and no residual or recurrence was noted on postoperative MRI at the 9-month follow-up. Primary melanoma of the spinal cord, particularly intramedullar localization, is seldomly reported in the literature. We report a primary malignant melanoma of the spinal cord and emphasize the diagnostic and prognostic challenges.

Keywords: Intramedullary; Malignant melanoma; Spinal cord neoplasms.

Fig. 1

Sagittal magnetic resonance imaging of the thoracic spine demonstrating an intramedullary spinal cord tumor between T9 and L1 levels. (A) The lesion is slightly hyperintense on T1-weighted images (B) iso- to hypointense on T2 weighted images with caudal and rostral cysts with multiple internal septa at the levels of T2 to T9 and L1 to L2. (C) Gadolinium enhanced T1-weighted images show mild homogeneous enhancement of the lesion.

Fig. 2

Operation microscope view of the surgical area. Dark gray pigmented intramedullary lesion is exposed after dural incision.

Fig. 3

Histopathological studies. (A) Photomicrograph shows highly cellular lesion composed of clusters of atypical cells with prominent nucleoli and marked eosinophilic cytoplasm (H&E, ×400). (B) Green arrows indicate dark brown pigmentation indicating the presence of melanin. (C) Positive immunoreactivity for HBM-45 (×200) and (D) S-100 protein (×200).