An armpit lump refers to enlargement of one or more lymph nodes under the arm.
Alternative Names
Lump in the armpit; Localized lymphadenopathy - armpit; Axillary lymphadenopathy; Axillary lymph enlargement; Lymph nodes enlargement - axillary; Axillary abscess
Considerations
Lumps in the armpit have various causes. Cysts and infections on the surface of the skin of the armpit may be caused by shaving or use of antiperspirants (as opposed to deodorants). This occurs most frequently in adolescents just beginning to shave. Abscesses under the skin may also produce large, painful lumps in the armpit.
Lumps may occur when lymph nodes are swollen due to bacterial or viral infections, vaccinations, and cancer.
Lymph nodes are filters that can catch infectious organisms or cancerous tumor cells. When they do, lymph nodes increase in size and are easily felt. A breast self-examination should always include the armpit because breast cancer can enlarge the armpit lymph nodes even when the breast itself seems perfectly normal.
A lump in the armpit caused by a generalized viral infection will eventually disappear without treatment. A lump in the armpit caused by an allergic reaction will go away after the "trigger" is removed. No treatment is necessary for a lump in the armpit caused by normal breast tissue. Usually, no treatment is necessary for a cyst.
A lump in the armpit caused by a lipoma is harmless, unless it grows so large that it causes discomfort.
The outlook for cancerous lumps depends on the specific type of cancer. See the following for more information:
Oguz A, Karadeniz C, Temel EA Citak EC, Okur FV. Evaluation of peripheral lymphadenopathy in children. Pediatr Hematol Oncol. 2006;23(7):549-561.
Zakaria S, Johnson R, Pockaj BA, Degnim AC. Breast cancer presenting as unilateral arm edema. J Gen Intern Med. 2007; 22(5):675-676.
Henry PH, Longo DL. Enlargement of lymph nodes and spleen. In: Kasper DL, Braunwald E, Anthony S. Fauci AS, eds. Harrison’s Internal Medicine. 16th ed. New York, NY: McGraw-Hill; 2005.
Review Date:
7/17/2007
Reviewed By:
Robert Hurd, MD, Professor of Endocrinology, Department of Biology, Xavier University, Cincinnati, OH, and physician in the Primary Care Clinic, Cincinnati Veterans Administration Medical Center, Cincinnati, Ohio. Review provided by VeriMed Healthcare Network.