OBJECTIVETo profile the clinicopathologic features of a series of grey zone lymphoma (GZL) cases with hybrid features of diffuse large B-cell lymphoma (DLBCL) and classical Hodgkin lymphoma (CHL), with a purpose to gain an in-depth understanding of the borderline B-cell neoplasm.

METHODSThe clinical, morphologic and immunophenotyical characteristics of 16 cases were retrospectively analyzed.

RESULTSThe patients were mostly male adults, with a male to female ratio of 1.7: 1.0 and a mean age of 40.2 years. Eight patients presented with peripheral nodal lesions and five cases with mediastinal involvement. Histologically and immunophenotypically, the 16 cases were classified into three sub-categories. In 4 cases, the morphologic features resembled CHL more closely, but the neoplastic cells showed uniform and intense positive staining of CD20 (pattern 1). Although the initial impression of the other 8 cases was that of DLBCL, the expression levels of CD20 and PAX5 were variable, and CD30 or CD15 was positive (pattern 2). A characteristic feature of pattern 3, observed in the remaining 4 cases, demonstrated a broad spectrum of morphology with hybrid features of both CHL and DLBCL. The neoplastic cells in pattern 3 were positive for CD20, CD30 and CD15. EBV-LMP1 was detected in 6 of the 11 tested cases. Clinically, most patients with GZL seemed insensitive to immuno-chemotherapy of the R-CHOP regimen.

CONCLUSIONSThe diagnostic criteria for GZL with features intermediate between DLBCL and CHL is proposed by the three histologic patterns commonly seen in these lesions. Cases presented with peripheral lesions might differ from those with mediastinal presentation pathologically. At current time, there is no effective treatment for these borderline B-cell lymphomas and the prognosis is poor.