Synchronous early-stage breast cancer and axillary follicular lymphoma diagnosed by core needle biopsy: A case report.

Synchronous double cancers are an infrequent finding. The focus of this study was a case of diagnosed synchronous double breast cancer (BC) and axillary (Ax) follicular lymphoma (FL). The patient was a 73-year-old woman who had been visiting her local doctor for follow-up of a fibroadenoma of the left breast, and was referred to our hospital after being diagnosed with invasive ductal carcinoma (IDC) of the left breast. Ultrasonography (US) revealed enlarged Ax lymph nodes (LNs) and US-guided core needle biopsy (CNB) was performed. CNB revealed no metastasis of IDC; however, a diagnosis of FL was made. Therefore, the patient was diagnosed with synchronous double BC and Ax FL and underwent partial surgical resection of the BC and close monitoring of the FL. To the best of our knowledge, this is the first case of malignant lymphoma diagnosed by CNB of Ax LNs during preoperative BC screening. CNB allows for a shorter waiting time for the examination, and it is considered to be minimally invasive, cost-effective and non-inferior to surgical resection in terms of specimen volume. Therefore, active preoperative evaluation of Ax LNs using US-guided CNB may contribute to BC staging, and may also help diagnose synchronous cancers.