Diagnosis and management of breast lymphoma: a single-institution retrospective analysis

Background: Breast lymphoma (BL) is a rare entity. Although mimicking clinical presentation and radiological features of epithelial breast malignancies, prognosis and treatment management are different. Here we report our single institution experience in such population. Methods: The database of our pathology institute was retrospectively searched for breast neoplasms coded as lymphoma from January 2000 to January 2017. The assessed data were: gender, age at diagnosis, laterality, stage (primary or secondary), histopathological diagnosis and grading (high vs. low) treatment, recurrence and survival status. Progression-free survival (PFS), overall survival (OS) and 5-year recurrence rate were estimated. An exploratory analysis comparing survival (PFS, OS and 5-year recurrence rate) between high- and low-grade histotypes and primary and secondary stages was performed. Results: Fifteen patients were included in the analysis. All patients were affected by B-cell type lymphomas; the most frequent subtype was diffuse large B-cell lymphoma (DLBCL). Patients affected by high-grade lymphomas were treated with polychemotherapy followed in about half of cases by consolidative ipsilateral breast radiotherapy. Patients affected by low-grade lymphomas were treated with local treatment only (surgical resection +/- radiotherapy). No patient received radical surgery or axillary dissection. At a median follow up of 9 years, four patients had relapsed (all affected by high-grade lymphomas) with central nervous system (CNS) involved in half cases. Both median PFS and OS were not reached, but a slight trend toward a better survival was noticed in favor of primary breast lymphoma (PBL), while a clearer survival benefit was observed in the low-grade cohort. The estimated 5-year survival rate was 77% within the whole population, 78% vs. 66% for primary vs. secondary and 100% vs. 66% for low-grade vs. high-grade BL. Conclusions: Our data concerning clinical and pathological features are consistent with those previously reported. Management of disease was based on histology. Although being a rare disease it is mandatory to take it into account for differential diagnosis since treatment and prognosis differs widely from primary breast malignancies.