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Isochromosome 7Q: the Primary Cytogenetic Abnormality In Leukemia (1997) 11, 1367–1393 1997 Stockton Press All rights reserved 0887-6924/97 $12.00 CORRESPONDENCE CASE REPORT Isochromosome 7q: the primary cytogenetic abnormality in hepatosplenic gd T cell lymphoma ELC Alonsozana1, J Stamberg2, D Kumar1, ES Jaffe3, LJ Medeiros4, C Frantz5, CA Schiffer6,7, BA O’Connell6,7, S Kerman8, SA Stass1,7 and LV Abruzzo1,7 1Department of Pathology, Laboratories of Pathology, 2Division of Human Genetics, 5Department of Pediatrics, 6Department of Medicine, and 7Marlene and Stewart Greenebaum Cancer Center, University of Maryland, Baltimore, MD; 3Hematopathology Section, Laboratory of Pathology, National Cancer Institute, National Institutes of Health, Bethesda, MD; 4Division of Pathology, City of Hope National Medical Center, Duarte, CA; and 8American Medical Laboratories, Chantilly, VA, USA Malignant lymphomas often have complex, nonrandom Because of its unique clinical and histopathologic features, chromosomal abnormalities. Hepatosplenic gd T cell lym- gd gd hepatosplenic TCL has been proposed as a distinct clinico- phoma ( TCL) is an unusual post-thymic T cell lymphoma that 4 primarily involves liver and spleen, often in young adult males. pathologic entity. Recently isochromosome 7q [i(7q)] was gd 6,7 Few cases have had cytogenetic analysis. We report a consist- reported in seven cases of hepatosplenic TCL. We have ent isochromosome 7q [i(7q)] abnormality in three cases of previously reported three additional cases of hepatosplenic hepatosplenic gdTCL, one with i(7q) as the sole abnormality gdTCL with cytogenetic analysis in abstract form.8 All three at presentation. Three patients, 15-, 37- and 65-year-old males, cases exhibited a common structural cytogenetic abnormality, presented with hepatosplenomegaly and fevers. Histopatho- i(7q). In one case, i(7q) was the sole abnormality identified on logic, immunophenotypic, and molecular genetic studies sup- ported the diagnosis. Spleen, liver, and bone marrow contained the initial diagnostic study. The second case had three sinusoidal infiltrates of atypical lymphoid cells of T cell immun- additional abnormalities, and the third case had a complex ophenotype. PCR performed on two cases demonstrated clonal karyotype with multiple numerical and structural abnormali- T cell receptor g gene rearrangements. Cytogenetic analysis of ties in addition to the i(7q). These cases represent the ninth to bone marrow showed i(7q) as the sole abnormality at presen- 11th cases of i(7q) reported in hepatosplenic gdTCL, and only tation in one case. The second case showed i(7q) in addition the second case with i(7q) as the sole abnormality. These to two normal chromosomes 7, and other structural and gd numerical abnormalities. The third case showed i(7q) and a results support the proposal that hepatosplenic TCL is a dis- deletion in the long arm of chromosome 11. These findings tinct clinicopathologic entity. Furthermore, they implicate support the proposal that i(7q) represents the primary nonran- i(7q) as the defining cytogenetic abnormality. dom cytogenetic abnormality in hepatosplenic gdTCL, and plays a role in its pathogenesis. Keywords: T cell lymphoma; hepatosplenic lymphoma; isochromo- Materials and methods some; chromosome 7 All cases were collected from the files of the University of Maryland Medical Center and the Hematopathology Section Introduction in the Laboratory of Pathology of the National Cancer Insti- tute. Two cases (cases 1 and 2) were seen in consultation by ab The T cell receptor (TcR) normally consists of either an or one of us (ESJ); the clinical and pathologic features of these gd heterodimer associated with a CD3 complex of proteins cases have been reported recently.5 Two patients (1 and 3) ab on the cell surface. Most mature T cells express the hetero- were referred to the University of Maryland from outside hos- gd dimer. A minority of mature T cells express the hetero- pitals for evaluation and treatment. Hematoxylin and eosin dimer. These cells are found primarily in the splenic red pulp (H&E)-stained histologic sections were prepared at the submit- 1 and intestinal epithelium. Like most normal T cells, most lym- ting institutions. Additional sections were prepared from the ab 2 phomas of T cell lineage express the heterodimer. Hepa- submitted paraffin blocks of formalin-fixed tissue. In all cases, gd gd tosplenic T cell lymphoma ( TCL) is an unusual peripheral spleen and bone marrow specimens were studied. Additional gd 3–5 T cell lymphoma that expresses the TcR. Cytologically, tissue from liver was available in case 1, and transbronchial the neoplastic cells are uniform, medium-sized lymphoid cells biopsy tissue was examined in case 3. with dispersed chromatin, small nucleoli, and a moderate amount of pale cytoplasm. The cells preferentially involve the sinusoids of spleen, liver, and bone marrow. As a result, Immunophenotypic analysis patients often present with hepatosplenomegaly, although per- ipheral blood involvement is unusual early in the course of Immunophenotypic studies were performed on fixed, paraffin- the disease. This lymphoma has a marked predilection for embedded sections and fresh tissue. Fixed, paraffin-embedded young men. The prognosis is poor, and most patients die sections were analyzed by the avidin-biotin-peroxidase (ABC) within 2 years of diagnosis despite aggressive chemotherapy. technique, as described previously9 using a panel of anti- bodies to CD3, CD20 (L26), CD43 (Leu22), CD45RO (UCHL- Correspondence: LV Abruzzo, Department of Pathology, University 1, A6) and CD74 (LN-2). Immunophenotypic studies were of Maryland, 22 S Greene St, Baltimore, MD 21201, USA performed on fresh tissue using one of two methods. For cases Received 7 February 1997; accepted 17 April 1997 1 and 3, cell suspensions were analyzed by flow cytometry Correspondence 1368 as described previously.5 In cases 1 and 2, frozen sections were analyzed by the ABC technique.9,10 The panel of anti- bodies included antibodies to CD1a, CD2, CD3, CD4, CD5, CD7, CD8, CD10, CD11c, CD14, CD16, CD19, CD20, CD21, CD22, CD25, CD56, CD57, TcRb and TcRd. For case 2, flow cytometry was performed at an outside laboratory and results reported. Cytogenetic analysis Cytogenetic studies in cases 1 and 3 were performed at the University of Maryland on direct preparations of bone marrow and peripheral blood using standard techniques.11 The divid- ing cells were analyzed by Giemsa–trypsin banding. A series of six bone marrow specimens was examined over a 19 month period in case 1. A single bone marrow and a peripheral blood specimen were examined in case 3. A minimum of 25 (range 25–50) cells were analyzed for each sample, with the exception of the peripheral blood in case 3, in which only 12 cells were available for analysis. In case 2, cytogenetic studies were performed at an outside laboratory, and were available for review. For this case, bone marrow was examined with 20 cells analyzed, using similar techniques. Molecular diagnostic studies In all cases, analysis for rearrangement of the TcRg chain gene was performed by polymerase chain reaction (PCR) on DNA extracted from formalin-fixed, paraffin-embedded tissue as described previously.12,13 Southern blot analysis was also per- formed in case 3 on DNA isolated from bone marrow. b Hybridizations with probes to the TcR chain gene (Jb/III), the immunoglobulin heavy chain gene (JH), and the immunoglob- ulin kappa light chain gene (JK) were performed using a com- mercially available kit according to the manufacturer’s instructions (B/T Blue Gene Rearrangement Test System; Oncor, Gaithersburg, MD, USA). Results Clinical features Figure 1 Representative photomicrographs illustrate the histologic and immunophenotypic features. (a) Bone marrow and (b) spleen from patient 3 contain infiltrates of medium-sized lymphoid cells with The clinical features are summarized in Table 1. All patients irregular nuclear contours and a moderate amount of cytoplasm, were males, aged 15, 65 and 37 years at the time of diagnosis. with a predilection for sinusoidal involvement (H&E). Patient 1 presented with asymptomatic hepatosplenomegaly, (c) Immunoperoxidase stain for CD3 performed on spleen shows a T followed by fevers, nausea and vomiting, and a petechial rash cell immunophenotype (hematoxylin counterstain). on his head and neck. His past medical history was unremark- able. Patient 2 presented with splenomegaly and thrombocy- Histologic and immunophenotypic findings topenia, and underwent splenectomy 5 months later for pre- sumed idiopathic thrombocytopenic purpura (ITP). After an The histologic and immunophenotypic features in all cases interval of 26 months he was re-evaluated for recurring fevers were similar. Spleen, bone marrow aspirate smears and core and thrombocytopenia. Patient 3 presented with fever and biopsies were available for review in all cases. All patients chills, and was found to have hepatosplenomegaly and lym- underwent splenectomy. The spleens were enlarged (patient phadenopathy. His past medical history was unremarkable. 1, 2264 g; patient 2, 705 g; patient 3, 2050 g) with homo- All patients received aggressive multiagent chemotherapy. geneous, dark red parenchyma. Representative sections of Although patient 1 achieved an initial clinical remission, the bone marrow and spleen from case 3 are presented in disease recurred and he died 25 months after diagnosis. Figure 1. The neoplastic cells were medium-sized lymphoid Patient 2 died 2 months after the diagnosis of gdTCL, and 33 cells with round to irregular nuclear contours, dispersed months after his initial presentation. The lymphoma in patient chromatin, occasional small nucleoli, and a moderate amount 3 was refractory to therapy, and he died 7 months after of pale cytoplasm. The splenic red pulp was expanded and diagnosis. sinusoids were dilated by atypical lymphoid cells in all three Correspondence 1369 Table 1 Summary of clinical features Case Age/Sex Anemia Dec. Plts H/S LN Skin BM Outcome 1 15/M +++/+− − + DOD, 25 months 2 65/M +++/+− − + DOD, 33 months 3 37/M +++/+− − + DOD, 7 months Dec. Plts, decreased platelets; H/S, hepatosplenomegaly; LN, lymph node involvement; BM, bone marrow involvement; DOD, died of disease.
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