Apocrine Cells: Definition

Apocrine cells are a type of glandular cell found in specific areas of the body, particularly in the skin. Under the microscope, apocrine cells are large and round with a visible central nucleolus (a small structure inside the nucleus). Their cytoplasm, the material surrounding the nucleus, often looks bright pink on a hematoxylin and eosin (H&E) stained slide. This pink color comes from proteins inside the cell that strongly attach to eosin, the pink dye used in the H&E stain.

What do apocrine cells do?

Apocrine cells produce a protein called the androgen receptor (AR). This receptor enables cells to respond to hormones known as androgens, which are part of the group of male hormones but are also present in both men and women. These hormones regulate the growth and function of apocrine cells.

Pathologists can test for androgen receptors using a technique called immunohistochemistry. This test uses special antibodies that attach to androgen receptors, making them visible under the microscope.

Where are apocrine cells normally found?

Most apocrine cells are found in the skin, where they form specialized sweat glands. They are also normally present in the areola, the pigmented area around the nipple.

In some situations, cells that are generally not apocrine can change into apocrine cells. This process is called apocrine metaplasia, and it most often happens in the breast. Apocrine metaplasia is a benign (non-cancerous) change and is commonly seen as part of fibrocystic change.

What types of tumors are made up of apocrine cells?

Both benign (non-cancerous) and malignant (cancerous) tumors can be made up of apocrine cells:

• Benign tumors: Several types of skin tumors and some breast tumors may contain apocrine cells. These tumors are not cancerous, and the cells do not spread to other parts of the body.

• Malignant tumors: Cancers that can be made up of apocrine cells include apocrine carcinoma of the skin, invasive apocrine carcinoma of the breast, and salivary duct carcinoma of the salivary glands.

Like normal apocrine cells, tumors composed of apocrine cells typically produce androgen receptors. Pathologists often test for AR in these tumors because it helps confirm the diagnosis and may provide information about treatment options.

Questions to ask your doctor

• Why were apocrine cells mentioned in my pathology report?

• Were they seen in a benign change, such as apocrine metaplasia, or in a tumor?

• Was androgen receptor (AR) testing performed, and what did the results show?

• Do the findings have any impact on my treatment or follow-up care?