Primary breast diffuse large B cell lymphoma

Abstract

Primary breast lymphoma (PBL) is an uncommon type of breast malignancy. Its clinical presentation and radiographic findings are non-specific and overlap with breast carcinoma. The treatment of PBL differs significantly from breast carcinomas. Here we present a middle-aged woman who presented with an enlarging palpable right breast mass. Mammogram showed breast imaging-reporting and data system 4 findings. Breast mass biopsy pathology confirmed diffuse large B cell lymphoma. Although uncommon, clinicians should be cognisant of the possibility of PBL when patients present with a breast mass. Accurate diagnosis is essential to avoid unnecessary mastectomies.

Keywords: Breast cancer; Breast surgery; Malignant and Benign haematology; Medical management.

Figure 1

Images of right breast mass. (A) Mammogram. An oval indistinct equal density mass with no associated calcifications measuring grossly 5.2×3.4 cm was visualised within the right breast at the 12 o’clock position 6 cm from the nipple. (B) Targeted ultrasound. An oval, parallel, heterogeneous predominantly hypoechoic mass with indistinct margins measuring 3.9×2.1×4.1 cm was visualised within the right breast at the 12 o’clock position approximately 5 cm, associated with faint posterior acoustic enhancement.

Figure 2

Breast high-grade diffuse large B cell lymphoma. (A) H&E stain, with markedly atypical large neoplastic cells; (B) MYC immunohistochemistry (IHC) stain, the viable neoplastic cells overexpress MYC; (C) CD20 IHC stain, the neoplastic cells are strongly positive for CD20; (D) Ki-67 IHC stain, the neoplastic cells have a high proliferation index.

Figure 3

(A and B) Pretreatment positron emission tomography/CT (PET/CT) demonstrates fluorodeoxyglucose (FDG) a 4.8×3.4 cm hypermetabolic mass in the right breast (solid arrow in A), FDG-avid right axillary lymph node (dashed arrow in A) and internal mammary lymph node (dashed arrow in B), and a second FDG-avid nodule measuring up to 1.1 cm between the pectoralis major and minor (solid arrow in B). (C, D and E) PET/CT after three cycles of R-CHOP therapy (R: rituximab, C: cyclophosphamide, H: doxorubicin hydrochloride, O: vincristine sulfate, P: prednisone) shows significant decrease in size and hypermetabolism of a right breast mass (solid arrows in C and E), and resolution of right axillary, subpectoral and internal mammary adenopathy. (F). PET/CT after six cycles of R-CHOP therapy shows the right breast mass continues to contract (solid arrow in F), measuring 1.2×0.7 cm, with mild accumulation of the radiotracer similar to the last examination.