Fig. 2

Xp11 translocation-associated cancers involving MED15-TFE3 gene fusion. a, b Case 20 showed an extensively cystic architecture, featuring thin fibrous septa of cells with abundant clear to granular cytoplasm and closely mimicking multilocular cystic renal neoplasm of low malignant potential. The tumor cells showed diffuse cytoplasmic labeling for cathepsin K (c) and Melan-A (d). Case 21 (e) and case 16 (f) were also extensively cystic, reminiscent of multilocular cystic renal neoplasm of low malignant potential. g, h Case 22 demonstrated distinct cystic areas, mixed with solid and papillary areas. i Case 19 metastasized to the lung showing a solid nested pattern. j, k Case 1 demonstrated a nested architecture separated by a delicate vascular network featuring purely epithelioid cells with focal necrosis. Immunohistochemistry for PAX8 (l) was negative