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.