The spectrum of pathological diagnoses in non-sentinel axillary lymph node biopsy: A single institution's experience.

Although axillary lymphadenopathy is a common clinical encounter, systemic evaluation of non-sentinel lymph node biopsy is sparse. We reviewed our institution's 15-year experience to delineate the spectrum of diagnoses in non-sentinel axillary lymph nodes. 1165 non-sentinel axillary lymph node biopsies were retrieved and the diagnosis and relevant clinical information was reviewed. This spectrum of diagnoses was further stratified by gender, age, and oncologic history. The spectrum of diagnoses included: breast carcinoma (27.6%), lymphoma (29.2%), melanoma (3.5%), other carcinoma (2.9%), sarcoma (0.4%), and benign changes (36.3%). The most common diagnoses in men were lymphoma (61.8%) and benign changes (23.6%); while in women they were benign change (41.2%), breast carcinoma (37.8%) and lymphoma (16.7%). Besides benign changes, lymphoma and breast carcinoma were most common in women younger and older than 30 years, respectively. In patients with a history of malignancy, the most common diagnoses were metastasis from the known tumor and benign change; while in patients with a negative oncologic history and female patients without a history of breast cancer, the diagnosis was generally either lymphoma or benign change. Anaplastic large cell lymphoma was rare but may be mistaken as metastatic carcinoma thus a high index of suspicion is warranted. Thus through retrospective review of a large cohort of non-sentinel axillary lymph node biopsies, we described the spectrum of pathological entities based on the gender, age, and clinical history, which could provide valuable information for further work-up of axillary lymph node biopsy.