Excessive therapeutic response in a case of blastic plasmacytoid dendritic cell neoplasm (original) (raw)

2012, Clinical advances in hematology & oncology : H&O

A 65-year-old African American man had been followed in the hematology-oncology clinic since 2003 for monoclonal gammopathy of unknown significance (MGUS) and anemia. Bone marrow biopsy at the time of initial presentation was unremarkable. In August 2008, he began to develop violaceous cutaneous lesions, generalized lymphadenopathy, and pancytopenia. Punch biopsy of the left arm revealed superficial and deep perivascular and interstitial infiltrates of small-to intermediate-sized cells. A bone marrow biopsy in October 2008 showed infiltration of mononuclear cells of similar morphology and immunohistochemical phenotype (positive for CD4 and CD56). Additionally, flow cytometry of a cervical lymph node biopsy from the same month demonstrated a large population of cells expressing CD4, CD56, and CD123. Based on these findings, the diagnosis of blastic plasmacytoid dendritic cell neoplasm, formerly known as CD4-positive/CD56-positive hematodermic neoplasm or blastic natural killer cell lymphoma, was made. From November 2008 to June 2009, the patient received 8 cycles of cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) chemotherapy, with a good response. His cutaneous lesions and palpable lymph nodes rapidly decreased in size after the third cycle. Positron emission tomography (PET)/computed tomography (CT) scans indicated complete response after the eighth cycle. However, in August 2009, while evaluation for stem cell transplantation was being arranged, he again developed similar extensive cutaneous lesions over his