Lipomas are common subcutaneous fatty tumors. They are often hard to see but easy to palpate. Most are asymptomatic and, on physical examination, appear as rubbery, mobile lesions, most commonly on the trunk, neck and upper extremities. Sebaceous cysts are less commonly found in the axillae, appearing most often on the scalp, face and trunk. Often, a central punctum is visible.
Rapid growth is usually due to infection and presents as an inflamed, tender mass.
Axillary adenopathy most commonly accompanies an infectious process. Neither patient presented with a history consistent with infection. The large size of these masses would also be unusual for adenopathy. Embryologically, mammary development occurs during the fourth and fifth weeks of gestation in primitive galactic bands that extend from the axilla to the groin. As gestation progresses, the galactic band enlarges to form the mammary ridge, and the remainder of the primitive galactic band regresses.