Tubulocystic carcinoma component. A) Higher magnification of the image shown on figure 2B (H&E, 4×). B) The cystically-dilated tubules were lined by flat to polygonal cells (some with a hobnail profile) with enlarged nucleus, prominent nucleolus, and occasional abundant eosinophilic cytoplasm. The fibrous septae contained scattered fibroblast-like spindle cells interspersed within a collagenous stroma (H&E, 20×). C) Tubular cells were positive for AMACR (left, top) and CD10 (left, bottom), and CK19 (right) confirming their proximal and distal convoluted tubule cell origin, respectively (all images, 20×). Estrogen receptor was negative in both epithelial and stromal elements (not shown).