Fig. 2

Microscopic findings show an intracystic papillary projection composed of some ill-defined tumor nests in the fibrotic wall, representing the in situ lesion of the tumor (black arrows, a, H&E, 10×). Note the invasive components (black arrowheads, a, H&E) adjacent to the in situ lesion (A 10×; inset, 100×). The tumor cells have abundant eosinophilic cytoplasm and vesicular nuclei with focal “apocrine-like” decapitation secretion (b, H&E, 400×), suggesting apocrine gland carcinoma