ALBERT

Description: The clonality of nodular lymphocyte-predominant Hodgkin's disease (NLPHD) and the relationship to composite or sequential large-cell lymphomas (LCLs) is poorly understood. Clonal Ig heavy-chain gene rearrangements (lgHGR) have infrequently been observed in NLPHD by Southern hybridization. The goals of this study were (1) to determine if IgHGR could be identified by polymerase chain reaction (PCR) techniques in the LCL associated with NLPHD; (2) to determine if the lgHGR identified in the LCL could also be found in the associated NLPHD; and (3) to determine if Epstein-Barr virus (EBV) played a role a role in histologic progression to LCL. Using consensus primers to conserved regions in the lgH variable (V) and joining (J) region genes, we analyzed formalin-fixed paraffin-embedded sections from the biopsies of 25 patients referred to the National Cancer Institute (NCI) registry for NLPHD and LCL using both single-step and seminested V-J PCR. The histologically aggressive component was further subclassified as frank LCL or as L&H-cell-rich, but not fulfilling criteria for LCL. Matched samples representing both NLPHD and aggressive components were available in 13 cases. In 12 cases, only one component was available (aggressive, n = 8; NLPHD, n = 4). In addition, we also amplified, with 32P labeling, 12 cases of NLPHD without associated LCL. Two clonal IgHGR were identified in 29 cases (7%) of typical NLPHD, both of which were associated with LCL containing a similar sized band by PCR. The clonal identity of the bands in the NLPHD and associated LCL was confirmed by sequencing the products in these two cases. Eight of 10 cases (80%) of LCL associated with NLPHD contained a clonal band by this technique. By contrast, none of the cases classified as L&H-cell- rich contained an IgHGR. The single-step and seminested PCR methods produced identical results. All clonal LCLs were studied for EBV sequences by in situ hybridization using the EBER1 probe, and were negative. We conclude that the LCLs associated with NLPHD are clonal B- cell malignancies. However, by these methods, the same clone can be identified in only a minority of cases of NLPHD and LCL. EBV does not appear to play a role in histologic progression. Moreover, our results suggest that many cases suspected of being LCL may actually represent NLPHD with increased numbers of L&H cells. In histologically equivocal cases, the diagnosis of LCL should be reserved for those cases in which a clonal B-cell neoplasm can be demonstrated.

Description: We identified eight cases of T-cell lymphoma with evidence of a gamma delta phenotype over a 13-year period. Seven of these cases conformed to a distinct clinicopathologic entity of hepatosplenic gamma delta T- cell lymphoma. Nearly all of these patients were young adult males (five of seven), with a median age at presentation of 20 years. They presented with marked hepatosplenomegaly, without lymphadenopathy or significant peripheral blood lymphocytosis. Thrombocytopenia was seen in all patients, and five of seven were mildly anemic. The clinical course was aggressive, and despite multiagent chemotherapy, the median survival duration was less than 1 year. The morphologic findings were uniform; a monomorphic population of medium-sized lymphoid cells with moderately clumped chromatin and a rim of pale cytoplasm infiltrated the sinusoids of the spleen, liver, and bone marrow. The cells had a characteristic immunophenotype: CD2+, CD3+, CD4-, CD5-, CD7+, CD16+, CD57-, CD25-, T-cell receptor (TCR)delta +, beta F1-. CD8 was positive in four of seven cases tested, and CD56 was positive in five of six. All cases expressed the cytotoxic granule-associated protein, TIA1, but perforin was detected in only one case. All cases with assessable DNA had a TCR gamma gene rearrangement, and lacked Epstein-Barr virus sequences. Isochromosome 7q was identified in two cases with cytogenetic information. The one case of cutaneous gamma delta T-cell lymphoma differed in its clinical manifestations, histologic appearance, and immunophenotype. We conclude that hepatosplenic gamma delta T-cell lymphoma is a distinct clinicopathologic entity derived from cytotoxic gamma delta T cells, and should be distinguished from other lymphomas of T-cell and natural-killer cell (NK)-like T-cell derivation.

Description: The occurrence of a large-cell lymphoma (LCL) concurrent with or subsequent to lymphocytic predominance Hodgkin's disease (LPHD) is well documented. Given the well-characterized B-cell nature of the Reed- Sternberg cell variants in LPHD, there may be a clonal relationship between the LPHD and the associated B-cell LCL. In this study, we adapted a highly sensitive, clonospecific assay to test whether the clone comprising the LCL exists in the corresponding LPHD tumor. Nine cases meeting the histologic criteria of nodular LPHD and B-cell LCL were identified, reviewed, and studied. Initially, clonality of both lesions was assessed using consensus primers to conserved regions in the IgH variable (frame-work III) and joining region genes in a polymerase chain reaction (PCR) assay. The PCR assay detected a clonal B-cell population in five of the LCLs, whereas analysis of eight cases of LPHD did not detect a dominant clone. Clonal products from the LCL were then sequenced, and clonospecific oligonucleotides were designed from the unique nucleotide sequence encoding the complementarity- determining region-III. These were then used as primers and/or probes in sensitive PCR-based assays on the corresponding LPHD tumors. In two cases, the clonospecific assay showed that the LPHD and LCL shared a common clone that was further confirmed by sequence analysis. This finding provides genotypic evidence that, at least in some cases, the LCL represents a clonal progression of LPHD.

Description: We identified eight cases of T-cell lymphoma with evidence of a gamma delta phenotype over a 13-year period. Seven of these cases conformed to a distinct clinicopathologic entity of hepatosplenic gamma delta T- cell lymphoma. Nearly all of these patients were young adult males (five of seven), with a median age at presentation of 20 years. They presented with marked hepatosplenomegaly, without lymphadenopathy or significant peripheral blood lymphocytosis. Thrombocytopenia was seen in all patients, and five of seven were mildly anemic. The clinical course was aggressive, and despite multiagent chemotherapy, the median survival duration was less than 1 year. The morphologic findings were uniform; a monomorphic population of medium-sized lymphoid cells with moderately clumped chromatin and a rim of pale cytoplasm infiltrated the sinusoids of the spleen, liver, and bone marrow. The cells had a characteristic immunophenotype: CD2+, CD3+, CD4-, CD5-, CD7+, CD16+, CD57-, CD25-, T-cell receptor (TCR)delta +, beta F1-. CD8 was positive in four of seven cases tested, and CD56 was positive in five of six. All cases expressed the cytotoxic granule-associated protein, TIA1, but perforin was detected in only one case. All cases with assessable DNA had a TCR gamma gene rearrangement, and lacked Epstein-Barr virus sequences. Isochromosome 7q was identified in two cases with cytogenetic information. The one case of cutaneous gamma delta T-cell lymphoma differed in its clinical manifestations, histologic appearance, and immunophenotype. We conclude that hepatosplenic gamma delta T-cell lymphoma is a distinct clinicopathologic entity derived from cytotoxic gamma delta T cells, and should be distinguished from other lymphomas of T-cell and natural-killer cell (NK)-like T-cell derivation.

Description: Mutations of the p53 tumor suppressor gene have been described in several subtypes of non-Hodgkin's lymphoma, but the incidence of p53 mutations in mantle cell lymphoma (MCL) is unknown. We hypothesized that cases of MCL with a variant or high-grade cytology would have a higher likelihood of p53 mutations than typical MCL. We were also interested in the prognostic significance of p53 mutations in MCL. Therefore, a series of 53 well-characterized cases of MCL with DNA from 62 tissue samples were analyzed by the polymerase chain reaction with denaturing gradient gel electrophoresis for exons 5–8 of p53. Immunoperoxidase studies with the antibody DO-7 to p53 protein were also performed on frozen sections. We found mutations of the p53 gene in 8 of the 53 cases (15%) of MCL. Missense mutations predominated, and 50% of the mutations occurred at known p53 hotspot codons. Of 21 cases with variant cytology (ie, anaplastic or blastic), 6 (28.6%) had p53 mutations as compared with only 2 of 32 cases (6.3%) with typical MCL cytology (P = .05), and p53 mutations preceded the development of variant cytology in 2 patients. Overexpression of p53 protein was observed in 6 of the 8 cases (75%) with p53 mutations and in none of the 45 wild-type cases. The median survival of the cases with mutant p53 was only 1.3 years (all died), whereas the median survival of cases with germline p53 was 5.1 years (P = .023). These results suggest that mutations of p53 may be one mechanism involved in the development of variant forms of MCL and indicate that p53 mutations in MCL predict a poor prognosis.

Description: Primary CD30(Ki-1)-positive anaplastic large-cell lymphoma (ALCL) is considered by some to be a distinct clinicopathologic entity associated with the t(2;5) (p23;q35). However, the specificity of t(2;5) for ALCL has not been carefully studied. Therefore, we performed a detailed analysis of all cases of ALCL with abnormal cytogenetics results in the Nebraska Lymphoma Study Group registry, as well as all other cases of non-Hodgkin's lymphoma with t(2;5) in the registry. We found the t(2;5) in only five of 10 cases of ALCL, four of whom were young patients. However, we also found the t(2;5) in 11 other cases of nonanaplastic lymphoma, including eight children with typical peripheral T-cell lymphomas of various types. The t(2;5) was also found in three older adults with B-cell lymphomas of various types. Thus, the t(2;5) was not specific for CD30+ ALCL. However, t(2;5) may define a clinicopathologic entity in children and young adults characterized by variable morphologies with a T-cell or indeterminate phenotype, CD30-positivity, nodal disease with frequent extranodal involvement, advanced stage, and an excellent response to therapy, including bone marrow transplantation for relapsed disease. The clinical relevance of the t(2;5) in older patients requires further study.