Clinicopathological analyses of 5 Japanese patients with CD56(+) primary cutaneous lymphomas

We analyzed the clinicopathological features of 5 Japanese patients with CD 56(+) primary cutaneous lymphomas (3 men and 2 women aged 25 to 73 years). Except for 1 patient in whom bone marrow involvement was simultaneously obs erved, all patients presented with cutaneous lesions. Based on their Epstei n-Barr virus (EBV) status, we categorized these patients into 2 groups, nam ely EBV-encoded small RNA-1 (EBER-1) (3 patients) and EBER-1(-) (2 patients ). Generalized lymph adenopathy and bone marrow involvement were observed o nly in EBER-1 patients. Morphologically, angiocentric proliferation was mor e prominent in EBER-1(+) patients and was accompanied by panniculitis-like changes. The lymphomas in EBER-1(-) patients featured monomorphic prolifera tion of lymphoblastic cells with no cytoplasmic granules. Phenotypically, C D3(-), cytoplasmic CD3 epsilon (+), and CD56(+) were common findings in bot h types. The EBER-1 type showed an additional distinguishing feature, CD7(), CD4(+), CD8(-), HLA-DR+, and terminal deoxynucleotidyl transferase-posit ive (TdT(+)) phenotype. The lymphoma was primarily resistant in the EBER-1( +) type, and the patients died within 6 months of admission. In contrast, t he lymphoma in the EBER-1(-) patients was originally chemosensitive. Collec tively, we consider there to be at least 2 types of CD56(+) primary cutaneo us lymphomas, corresponding to nasal-type natural killer (NK)/T-cell lympho mas (EBER-1(+)) and blastic NK-cell lymphomas (EBER-1(-)). Int J Hematol. 2 000;72.477-483. (C)2000 The Japanese Society of Hematology.