What are Skin Adnexal Tumors?
Skin adnexal tumors (SATs) are new growths involving the skin appendages, namely :
the hair follicles (trichilemmal tumors or cysts)
- the sweat glands (apocrine and eccrine tumors)
- the oil glands (sebaceous tumors)
As skin appendages, hair, sweat and oil glands are scattered all over the body, although more are found in the scalp, axilla (armpits), the extremities, the genitals, the anus, the chest, and around the nipples. Therefore, tumors may be found more in these areas. Other parts of the body that may be affected are the eyelids, the outer ears and the breast.
Most SATs are slow growing, benign or not life threatening and are confined to a small area (localized). However, in rare cases they may begin to proliferate or grow abnormally fast and changes in cell structures are seen as cancerous or malignant. They may be locally invasive but can also spread to the lymph nodes and distant organs like the lungs, bone and liver. These tumors may also be primary new growths or they may be a result of another cancer in the body that has metastasized or spread distantly.
Proliferating adnexal tumors are very rare, composing only 0.005% of all skin tumors. They are usually found in middle aged and older women, but some are also found in men and children. They may be asymptomatic and initially appear as a small painless bump with no other significant skin changes.