To evaluate the value of ¹⁸F-FDG PET/CT in the diagnosis and treatment of primary breast lymphoma (PBL).

Clinical data and ¹⁸F-FDG PET/CT imaging data of 6 patients (all females, age 46-79 years) with pathologically diagnosed primary breast diffuse large B cell lymphoma (PB-DLBCL) in Xishan People′s Hospital of Wuxi City and Affiliated Hospital of Jiangnan University from July 2015 to October 2021 were analyzed retrospectively. A total of 10 ¹⁸F-FDG PET/CT scans were done for primary staging (6 scans of 6 patients), evaluation of treatment response (3 scans of 2 patients), and recurrence detection (1 scan of 1 patient). ¹⁸F-FDG PET/CT image analysis was performed qualitatively (visually) and semi-quantitatively (SUV_max). Treatment response was evaluated by Deauville scores.

All 6 patients were diagnosed pathologically as PB-DLBCL (3 patients by core needle biopsy, 3 patients by biopsy after lumpectomy). All 6 patients were staged using baseline ¹⁸F-FDG PET/CT before chemotherapy. For 3 patients diagnosed by core needle biopsy, baseline ¹⁸F-FDG PET/CT showed unilateral breast lesion with high FDG uptake (SUV_max: 23.0, 52.9, and 33.6). For 3 postoperative patients, baseline ¹⁸F-FDG PET/CT showed flocculent soft tissue density in the operative area with low FDG uptake (SUV_max: 3.4, 2.2 and 2.0). Patient No.2 showed a large left breast mass with left axillary lymph node involvement by baseline PET/CT, and multiple nodular uptakes in bilateral breast (Deauville score of 4) after 4 courses of chemotherapy and negative result (Deauville score of 1) after 3 courses of new chemotherapy regimens by PET/CT. Patient No.4 showed right breast lesion and right axillary lymph nodes by routine preoperative imaging examination, but left breast lesion by postoperative PET/CT. According to the results of ¹⁸F-FDG PET/CT, patient No.4 was with complete response (Deauville score of 1) after treatment, but recurrence (Deauville score of 5) occurred after 7 months follow-up.

¹⁸F-FDG PET/CT can play an important role in every step of management (diagnosis and staging, treatment response evaluation and detection of recurrence) in patients with PB-DLBCL.

Lymphoma, large B-cell, diffuse; Breast neoplasms; Positron-emission tomography; Tomography, X-ray computed; Fluorodeoxyglucose F18