CD56-POSITIVE (NASAL-TYPE-T NK-CELL) LYMPHOMA ARISING ON THE SKIN - REPORT OF 2 CASES AND REVIEW OF THE LITERATURE

Several authors have reported cases of patients with malignant lymphom a with unique characteristics, designated nasal-type T/NK cell lymphom a, which expresses the natural killer (NK) cell marker and shows frequ ent extra-nodal involvement and poor prognosis. We report 2 cases of t his type of lymphoma which were CD56-positive and showed a histopathol ogically angiocentric pattern with cutaneous and subcutaneous tumorous lesions, Patient 1 had extensive invasion of skin, underlying skeleta l muscle, spleen and bone marrow and died of sepsis 34 months after on set, Patient 2 had multiple subcutaneous nodules and invasion to mamma ry gland, lung, lymph node and spleen at the time of her first visit, She died of a rapid invasion of lymphoma cells to the liver 5 months a fter onset, Both patients showed similar immunophenotypes of tumor cel ls (CD2+, CD3-, CD4-, CD8-, CD20-, CD56+) and germ line configuration of the heavy chain of immunoglobulin (JH),T-cell receptor C beta-1 sub unit DNA and T-cell receptor J gamma subunit DNA, Epstein-Barr virus e arly regions RNA was demonstrated in the nuclei of tumor cells of both pa patients with in situ hybridization. The histopathological examina tion of the skill lesions of both patients revealed the features of an giocentric lymphoma. The detection of CD56 in the tumor cells of cutan eous lymphomas should be routinely performed for the early diagnosis o f this type of lymphoma with extremely poor prognosis. (C) Munksgaard 1997.