Fine-needle aspiration of intramammary lymph nodes: a clinical, radiographic, and cytologic review.

Abstract

Recognizing and sampling intramammary lymph nodes (IMLNs) is important in the clinical management of patients with breast carcinomas. We undertook a retrospective study to evaluate the clinical utility of fine-needle aspiration (FNA) in assessing IMLNs. Our pathology database was searched for all IMLN FNA cytology cases from January 2005 to December 2021. The cytologic findings, radiographic features, and clinical data were reviewed. A total of 149 cases were identified. Eighteen of 149 (12%) patients had synchronous breast tumors, including 13 invasive ductal carcinomas (IDCs), 1 ductal carcinoma in situ (DCIS), and 4 fibroadenomas. Among patients with synchronous IDCs, FNA of IMLNs was positive for metastatic carcinoma in 4 of 13 (30.7%) cases. The 4 patients with positive IMLNs all received mastectomies. Fifteen of 149 (10.7%) patients had a prior history of breast tumors, including 9 IDCs, 4 DCISs, 1 lobular carcinoma in situ (LCIS), and 1 fibroadenoma. Two of 149 (1.3%) patients had a prior history of lymphoma. In the patients with prior history of IDC, DCIS, LCIS, lymphomas and fibroadenomas, IMLN FNAs were all negative for malignancy. Two of 149 cases (1.3%) showed granulomatous lymphadenitis. The remaining 112 cases had negative IMLN FNAs and no significant clinical or pathological findings. Our study showed that IMLNs are commonly associated with synchronous/metachronous breast tumors (33 of 149, 22.1%). The incidence of positive IMLN FNA in patients with synchronous invasive breast carcinoma was 30.7% (4 of 13). FNA of IMLNs in conjunction with clinical presentation and radiologic findings allows triage of patients for appropriate clinical management and avoids additional unnecessary surgical procedures.