Causes of misdiagnosis of primary breast lymphoma as breast cancer and differential diagnosis

ZHANG Zhenyu; LIU Zhengrui; LI Chao; WANG Fukai; TIAN Zhaokun; LIU Xiaoyu; YU Zhiyong

doi:10.3969/j.issn.1002-3429.2026.06.004

Abstract：Objective To investigate the causes of misdiagnosis of primary breast lymphoma(PBL)as breast cancer and essential points for differential diagnosis.Methods A retrospective analysis was conducted on the clinical data of 4 patients with PBL misdiagnosed as breast cancer who were admitted to the hospital from April 2022 to October 2024.Results All of the 4 patients with PBL visited the hospital due to breast masses and were initially diagnosed as breast cancer through physical examination and relevant examinations,including 2 cases of left-sided breast cancer,1 case of left-sided breast cancer with left axillary lymph node metastasis,and 1 case of right-sided breast cancer.All 4 patients underwent surgical treatment and were diagnosed with PBL by postoperative pathology and immunohistochemistry.Among them,there were 3 cases of stage II B-cell non-Hodgkin lymphoma and 1 case of stage III.The time of misdiagnosis ranged from 5 to 40 d,with an average of(16.36±2.89)d.Patients were given adjuvant radiotherapy and chemotherapy after surgery.The patients were followed up for 3-22(11.69±2.30)months.Of them,3 patients survived,while 1 patient died after recurrence at 1 year postoperatively.Conclusion PBL lacks specific clinical manifestations,and related medical examination results are complex,making it prone to misdiagnosis as breast cancer.It is recommended to enhance clinical recognition of PBL.Comprehensive analysis combining medical history,physical examination,and relevant laboratory and imaging findings should be conducted during diagnosis,along with careful differential diagnosis.Timely breast mass biopsy with pathological and immunohistochemical examinations should be conducted for suspicious cases to reduce the misdiagnosis rate.