The common causes of axillary lymph node enlargement are: axillary lymphadenitis, metastatic breast cancer, and lymphoma.
Patients with lymphoma commonly develop lymphoma in the neck, clavicle, groin, etc. Lymphoma in the armpit is also common and requires surgical excision to determine the nature of the pathology. The lymph node enlargement should be seen in the hospital as soon as it is detected.