Malignant melanotic nerve sheath tumors in the spinal canal of psammomatous and non-psammomatous type: Two case reports

Figure 1 A 58-year-old female with psammomatous melanotic schwannoma. A: Axial T1-weighted image of 11-12^th thoracic spine level shows low signal mass lesion (arrows) located in the intradural space; B: Axial T2-weighted image shows the mass lesion (arrows) with heterogeneously high signal intensity and the spinal cord (thick arrow) is displaced and compressed by the mass lesion; C: The mass lesion (arrows) represents heterogeneously strong enhancement containing necrotic portion on sagittal fat-suppressed, contrast-enhanced T1-weighted image; D: Amorphous linear calcification (black arrow) is noted in the peripheral margin of the mass on the computed tomography scan; E: Section shows spindle-shaped Schwann cells with brownish pigments, psammoma bodies (hematoxylin and eosin, × 100); F: Positive immunoactivity for S-100 protein that are characteristic features of psammomatous melanotic schwannoma (× 100).