Unilateral axillary lymphadenopathy (differential)

Unilateral axillary lymphadenopathy while being more concerning than bilateral axillary lymphadenopathy can still arise from a variety of benign, as well as malignant, causes.

Benign
Malignant
  • metastasis from breast malignancy
  • metastasis from non-breast malignancies
    • melanoma: a relatively common non-breast primary malignancy to present with axillary lymphadenopathy
    • primary malignancy in ipsilateral arm
  • lymphoma: can occasionally be unilateral

See also