November 30, 2023
Apocrine cells are large pink cells with a round nucleus and a prominent central nucleolus. These cells look pink when examined under the microscope because the cytoplasm (body) of the cell is full of proteins that stick to eosin (a pink dye) in the hematoxylin and eosin (H&E) stain. Apocrine cells normally produce a protein called androgen receptor (AR) which allows the cells to respond to a group of hormones called androgens. Pathologists perform a test called immunohistochemistry to look for androgen receptors inside cells.
Most normal apocrine cells are found in the skin where they connect to form specialized sweat glands. Apocrine cells can also be found in a part of the nipple called the areola. Cells that are not normally apocrine can also become apocrine over time. Pathologists describe this as apocrine metaplasia and the most common location for apocrine metaplasia is the breast.
Several different types of non-cancerous skin tumours can be made up partially or entirely of apocrine cells. Some non-cancerous breast tumours can also be made up partially or entirely of apocrine cells. Cancers made up of apocrine cells include apocrine carcinoma of the skin, invasive ductal carcinoma of the breast with apocrine features, and salivary duct carcinoma of the salivary glands. Like normal apocrine cells, tumours made up of apocrine cells produce androgen receptors (AR).