Apocrine

In apocrine secretion, secretory cells accumulate material at their apical ends, often forming blebs or "snouts", and this material then buds off from the cells, forming extracellular vesicles.

Apocrine-like cells form in a lining of developing microcysts, due to the pressure buildup within the lumen.

[6] Metaplastic apocrine cells belong to the category of oncocytes, which are a group characterized by abundant acidophilic, granular cytoplasm (from the Greek root onco-, which means mass, bulk).

ACDIS tumors have microscopic histopathology features that are similar to pure apocrine carcinoma of the breast tumors but differ from them in that they are completely localized, i.e. have not invaded nearby tissues or metastasized to distant tissues.

[8] Cytologically, the cells of apocrine carcinoma are relatively large, granular, and it has a prominent eosinophilic cytoplasm.