Subcutaneous Panniculitis-Like T-Cell Lymphoma of the Breast
A 43-year-old woman came to our hospital due to a palpable mass on the left breast that had been present for more than 3 months. On physical examination, a subcutaneous, poorly defined nodule was palpated in the upper inner portion of the left breast. No axillary lymphadenopathy was palpable.\nBilateral mammography performed with a Senographe 2000 D system (GE Healthcare, Milwaukee, WI, USA) showed a 5-cm, increased opacity with indistinct margin in the upper portion of the left breast (). No calcifications or architectural distortion were seen. On sonographic examination (LOGIQ 9 with a 12-MHz transducer; GE Healthcare, Milwaukee, WI, USA) performed immediately after the mammography, a diffuse hyperechogenicity with a poorly defined margin was detected in a subcutaneous fat layer of the left upper inner breast (). The multiple, linear hypoechoic areas were located within the diffuse hyperechogenicity. The sonographic findings suggested the possibility of edema or inflammation. However, a palpable mass had been present for more than 3 months and other symptoms suggesting the inflammation were not present, an ultrasound guided core biopsy was performed. On microscopic examination, the lesion disclosed no specific findings, except fibroadipose tissues with inflammation. She also noticed nodules in both upper arms and she had symptoms of arthritis, photosensitivity, and severe fatigue. She was clinically diagnosed as having lupus panniculitis and had a treatment with steroids. However, the symptoms were persistent and the number of the nodules was increased.\nAn excisional biopsy of the nodule in the left breast was performed. On microscopic examination, a dense lymphoid infiltrate located in the subcutaneous tissue. The overlying dermis and epidermis were not involved (). On high-power field, the lymphoid cells were atypical with irregular nuclei. There were numerous fat cells rimmed by atypical lymphoid cells. There were scattered and dispersed histiocytes, some with phagocytic cell debris (). Immunophenotypically, atypical lymphocytes were positive for CD3, CD8, cytotoxic proteins granzyme B, and T-cell intracellular antigen-1, and negative for CD4, CD20, and CD56 (). The rimming of individual adipocytes by the CD8+ and CD56-neoplastic T-cell and strict subcutaneous localization were consistent with a diagnosis of SPTCL. Treatment with systemic chemotherapy (A-CHOP, alemtuzumab, cyclophosphamide, doxorubicin, vincristine, and prednisone) and local radiotherapy were performed. After a total of 6 cycles of chemotherapy and local radiotherapy, the skin nodules decreased in size over the several weeks. She remained clinically well with no lesions detected for a 5 years follow-up period.