Complete Spontaneous Regression Of Primary Diffuse Large B-cell Lymphoma Of The Breast

Abstract

A healthy 69-year-old woman presented with a 4-week history of an elastic hard lump in the upper aspect of her left breast.Physical examination demonstrated a 4-cm, elastic, hard mass located in the midportion above the nipple of her left breast.Axillary lymphadenopathy was not found.There was no significant past medical history, and she was not taking any medication.Family history was negative for malignant disease.Mammography of the left breast showed a dense mass with an ill-defined border.Ultrasonography revealed a hypoechoic lesion, measuring 47 ϫ 46 ϫ 20 mm with an irregular margin.These diagnostic imaging findings suggested a malignant tumor.Further examination was by magnetic resonance imaging (MRI), and core needle biopsy (CNB) was performed to determine the histopathologic diagnosis.MRI (gadolinium-enhanced fatsuppressed T1-weighted imaging) showed high-contrast rim enhancement of the lesion and rapid washout on the time-intensity curve (Fig 1A).Histopathologic evaluation of the CNB specimen showed cellular proliferation of atypical cells (Fig 2A) and diffuse growth of large lymphoid cells with frequent mitotic figures.The cells had scanty cytoplasm surrounding round and oval nuclei with a fine chromatin pattern (Fig 2B).Immunohistochemical examination was performed and was negative for estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2 (HER2).For immunophenotyping of T-and B-cell lineage, monoclonal antibodies were used (DAKO, Copenhagen, Denmark), including antibodies specific for CD3 (F7.2.38), CD5 (CD5/54/F6), CD10 (56C6), CD20 (L26), MUM-1 (MUM1p), bcl-2 (124), CD30 (BerH2), and CD56 (MOC-1).The lymphoma cells were positive for CD20 (Fig 2C), MUM-1, and bcl-2 and negative for CD3, CD5, and CD10.In situ hybridization for Epstein-Barr virus EBER protein was negative, and the MIB-1 (DAKO) labeling index was evaluated at 80% to 90% (Fig 2D).On the basis of the pathologic features, the tumor was classified as a diffuse large B-cell lymphoma (DLBCL).Bone marrow aspiration was performed and revealed a slightly hypocellular bone marrow with no evidence of lymphomatous infiltration.Positron emission tomography-computed tomography (PET-CT) revealed a large homogeneous mass measuring approximately 50 mm located in the left breast.No systemic lymphadenopathy was detected.The PET-CT findings indicated a stage IE tumor according to the Ann Arbor staging system.After CNB, the patient noticed that the tumor regressed rapidly and was nonpalpable within 11 days, without any specific treatment for DLBCL.We performed excisional biopsy for further pathologic assessment.This yielded a specimen measuring 70 ϫ 56 ϫ 12 mm, and we took thin sections of the whole specimen and examined them.