Primary cutaneous large B-cell lymphoma - The relation between morphology,clinical presentation, immunohistochemical markers, and survival

The histogenesis, morphology, immunophenotype, and clinical behavior of cut aneous large B-cell lymphomas (CLBCL) are largely a matter of controversy. We performed an investigation to determine whether CLBCL have features that differentiate them from other large B-cell lymphomas and whether CLBCL is itself a heterogeneous group. To this end, we reviewed the main characteris tics of a series of 32 cases of LBCL found in the skin. We reviewed the cli nical findings and paraffin sections of the tumors from these 32 patients. The immunohistochemical study performed included p53, MIB1, Bcl2, Bcl6, and CD10 markers. We carried out statistical analysis of these data (univariat e and multivariate), seeking an association between the features of the tum ors and clinical outcome, as defined by failure-free survival time. Only on e patient died as a consequence of the lymphoma. Nevertheless, the accumula ted probability of survival without failure at 48 months was 0.46. The numb er, type, and localization of the lesions were not associated with variatio ns in either survival or failure-free survival. The expression of p53 was n egative in this group of CLBCL, whereas Bcl-2 expression or localization in the lower leg did not relate to any other significant feature. Histologic examination of the cases disclosed three different groups: Grade III follic ular lymphomas (FLs), monomorphous large B-cell lymphomas (LBCL type L), an d LBCL with an admired component of small B-lymphocytes (LBCL type II). Gra de III FL (11 cases) tended to be found in the head and neck and showed CD1 0 expression in a majority of cases. A higher probability of lymph node rel apses was associated with cases located in the head and neck and with CD10 tumors. Cutaneous large B-cell lymphomas are indolent tumors, but follow a n insidious course. Our data support the interpretation that CLBCL is a het erogeneous condition; comprises some LBCL derived from CD10+ germinal cente r cells which manifests more frequently as tumors in the head and neck regi on, with an increased probability of relapse in lymph nodes [1] and has som e distinctive morphologic features. The existence of a component of small B -cells within the other CLBCL could lend support to the theory that some of these tumors, more than arise de novo, may have originated in preexistent small B-cell lymphomas, but no firm evidence of this is provided in this st udy.