Epithelioid malignant peripheral nerve sheath tumor of the bladder and concomitant urothelial carcinoma: A case report

Figure 1 Epithelioid malignant peripheral nerve sheath tumor of the bladder. A: Non-invasive low grade papillary urothelial carcinoma seen on initial biopsy; B: Non-invasive low grade papillary urothelial carcinoma and atypical mesenchymal cell infiltration in the lamina propria determined on second biopsy (the area within the circle); C: SOX-10 immunopositivity in atypical mesenchymal cells (the area annotated with ellipse) located in the lamina propria in one of the tissue fragments representing the non-invasive papillary urothelial carcinoma; D: Focal myxoid stroma at the periphery of the tumor with a lobular growth pattern (an arc is used to distinguish normal urothelium from tumoral tissue); E: Epithelioid tumor cells with round vesicular nuclei, prominent nucleoli and abundant eosinophilic cytoplasm; necrosis in the upper left corner; F: Spindle tumor cells with fascicular growth (hematoxylin and eosin, SOX10, × 40, × 100 and × 200).

Figure 2 Immunohistochemical findings of epithelioid malignant peripheral nerve sheath tumor. A: Immunohistochemistry for SOX10 showing strong nuclear positivity of epithelioid tumor cells; B: Diffuse and strong immunopositivity for S100; C: CK7 immunohistochemistry shows patchy cytoplasmic positivity (staining cells are annotated with an ellipse); D: Occasional cells are positive for EMA (x 200). Arrows used to denote dispersed tumoral cells positively stained.

Figure 3 Radiological findings of epithelioid malignant peripheral nerve sheath tumor. A-B: Ultrasonography and computed tomography images of patient; B-C: The positron emission tomography computed tomography slices of the patient show a large radiodense mass filling the diverticulum and extending through the posterior wall of the bladder with significant fluorodeoxyglucose (FDG) uptake; D: Foci of metastasis on right lung detected on FDG-positron emission tomography scan (arrows on A-D used to annotate the descriptions).