Abstract

A 74-year-old woman, with history of stage 2 ER-negative, HER2-positive invasive ductal breast carcinoma s/p total mastectomy with negative sentinel lymph node biopsy and neoadjuvant chemotherapy, presented with a four-month history of an erythematous patch on her right upper arm. KOH showed hyphae and she was given ketoconazole cream. As the lesion was enlarging, a biopsy was then done revealing an atypical proliferation of T-lymphocytes that were CD3+, CD4+, CD5-, CD56-, and CD30-. T-cell gene rearrangement studies did not reveal clonality. The patient returned for an additional biopsy to complete FISH studies. Pathology showed a diffuse, dense superficial and deep dermal infiltrate of relatively monomorphous medium and large cells with prominent nucleoli and irregular nuclear contours, without epidermotropism. Cells were weakly CD56+, CD3+, TIA+, weakly CD4+, weakly granzyme+, CD5-, CD7-, CD8- CD10-, CD20-, CD30-, CD34-, CD123-, Bcl6-, and TdT-. The lesion grew into a bulbous several-centimeter tumor with two local satellite papulonodules and she developed right axillary lymphadenopathy. Core needle biopsy was consistent with cutaneous extranasal extranodal NK/T cell lymphoma. The rapidly enlarging tumor (size 12 x 10 x 8-cm) was excised and found to be EBV positive. EBV PCR blood was also positive. Bone marrow biopsy was unremarkable. The patient was treated with multiple regimens: CHOEP (cyclophosphamide, doxorubicin, vincristine, etoposide, prednisone), DeVIC (dexamethasone, etoposide, ifosfamide, and carboplatin), rituximab, and pembrolizumab. However, despite treatment, she developed worsening lymphadenopathy, hepatosplenomegaly, and multiple nodules on her extremities, face and neck. The patient developed sepsis, began decompensating, and the patient’ s family opted for comfort care. We present a case highlighting the immunohistochemical work up, along with clinical and pathologic features, important for early diagnosis of a disease with a poor prognosis.

Financial Disclosure:
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