Clinicopathological Features of Hematological Malignancies Presenting As Breast Lesions on Mammography: The Mount Sinai Medical Center Experience

Background:Breast involvement by hematological malignancies is extremely rare and encompasses approximately 1% of all breast tumors. In this retrospective data review, we aimed to evaluate the clinical, pathological and radiographic characteristics of hematological malignancies involving the breast.Methods:Our database was searched for "leukemia", "lymphoma" and "myeloma" in reports of breast biopsies, obtained between August 2009 and August 2019. A total of 13 cases met inclusion criteria.Results:A total of 13 breast biopsies with the diagnosis of leukemia or lymphoma were identified. All samples were obtained through ultrasound guided core needle biopsy. All 13 patients were females, 61.54% Caucasian, 15.38% Black, 15.38% Hispanic and 7.7% Asian, with median age of 71 years. In 8/13 patients (61.54%), a palpable breast lesion prompted the imaging study, while the remaining 5/13 patients (38.46%) were detected on routine screening mammography. Average lesion size was 2.7cm (±2.47cm, SD). On mammogram, 61.5% of cases were described as BIRADS 4, 30.8% as BIRADS 0 and 7.7% as BIRADS 5. Pathological evaluation revealed all cases (100%) were lymphomas. The commonest lymphoma subtype was marginal zone B-cell Lymphoma (MZL) (38.48%), followed by diffuse large B cell lymphoma (DLBCL) (15.38%) and small lymphocytic lymphoma (SLL) (15.38%). Burkitt's lymphoma (7.69%), follicular lymphoma (7.69%), hairy cell leukemia (7.69%) and lymphoplasmacytic lymphoma (7.69) were also identified. Primary breast lymphoma (PBL) was identified in 4/13 patients (30.77%), while in 9/13 (69.23%) the breast lesion were secondary breast lymphomas (SBL). Treatment options for patients with PBL consisted of local radiation in two patients, R-CHOP chemotherapy in one patient and immunotherapy with rituximab plus radiation in one patient. Patients with SBL received systemic chemotherapy. None of the patients were treated surgically.Conclusion:Hematological malignancies involving the breast can present as a palpable or subclinical lesions with a high BIRADS on mammography. MZL was the predominant subtype, followed by DLBCL and SLL. PBL can be a localized disease suitable for conservative management.