Lifespan's A - Z Health Information Library

An armpit lump refers to enlargement of one or more lymph nodes in the armpit.

Lump in the armpit; Localized lymphadenopathy - armpit; Axillary lymphadenopathy; Axillary lymphs enlarged; Lymph nodes enlarged-axillary; Axillary abscess

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 be produced by lymph nodes enlarged due to bacterial infections, viral infections, vaccinations, and malignancy. 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.

Lymph nodes are filters that can catch malignant tumor cells or infectious organisms. When they do, lymph nodes increase in size and are easily felt.

• Bacterial
  • Localized infection, possibly somewhere in the arm or breast draining into the glands of the armpit, or infection within the armpit itself
  • Cat scratch disease
  • Ascending lymphangitis
  • Lymphadenitis
• Viral
  • Infectious mononucleosis
  • Chickenpox
  • Shingles (herpes zoster)
  • HIV disease (AIDS)
• Malignant
  • Hodgkin's lymphoma
  • Non-Hodgkin's lymphoma
  • Leukemia
• Fungal
  • Sporotrichosis
• Antigenic
  • Smallpox vaccination
  • Typhoid vaccine
  • Measles, mumps, rubella vaccine (rare)
  • Allergic reaction possibly caused by sulfa drugs, iodine, or penicillin
• Other
  • Lipomas (harmless fatty growths)
  • Benign (harmless) cyst
  • Normal breast tissue (breast tissue extends into the armpit area)

Check with your health care provider to determine the nature of the lump.

For a lump in the armpit caused by an infected, painful gland, follow the instructions about the proper treatment for the underlying infection.

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.

For a lump in the armpit caused by a malignancy, follow the appropriate cancer treatment recommended by a doctor.

Call if you have any unexplained armpit lumps. Do not try to diagnose lumps without professional help.

Your doctor will perform a physical examination and ask medical history questions about the armpit lump, such as:

• When did you first notice the lump?
• Is it getting better, worse, or staying the same?
• Are you breast-feeding?
• Have you noticed any factors that make it worse?
• What other symptoms are also present?
• Is the lump painful?

The physical examination may include palpation -- gently pressing the nodes with the fingertips.

Testing depends on what is found during the physical examination. Diagnostic tests that may be performed include:

• Liver function tests
• Kidney function tests
• Lymph node biopsy
• Platelet count
• Routine blood work, such as a complete blood count (CBC)
• X-ray of the chest
• Liver-spleen scan
• Mammogram