[Extranodal diffuse large B-cell lymphoma--an organotypic disease?]

A rare entity of primary extranodal diffuse large B cell lymphoma of the lower limb calf in an HIV-infected young adult on highly active antiretroviral therapy

Primary cutaneous and skeletal muscle lymphomas are particularly rare phenomena in HIV sero-positive patients. The authors report a case of primary extranodal malignant diffuse large B cell lymphoma of the left gastrocnemius in a 21-year-old young adult who presented to the Infectious Diseases Institute, Kampala, Uganda having been on antiretroviral therapy for 2 years. The patient is still undergoing chemotherapy.

Tanzanian malignant lymphomas: WHO classification, presentation, ploidy, proliferation and HIV/EBV association

BACKGROUND

In Tanzania, the International Working Formulation [WF] rather than the WHO Classification is still being used in diagnosing malignant lymphomas (ML) and the biological characterization including the HIV/EBV association is sketchy, thus restraining comparison, prognostication and application of established therapeutic protocols.

METHODS

Archival, diagnostic ML biopsies (N = 336), available sera (N = 35) screened by ELISA for HIV antibodies and corresponding clinical/histological reports at Muhimbili National Hospital (MNH) in Tanzania between 1996 and 2006 were retrieved and evaluated. A fraction (N = 174) were analyzed by histopathology and immunohistochemistry (IHC). Selected biopsies were characterized by flow-cytometry (FC) for DNA ploidy (N = 60) and some by in-situ hybridization (ISH) for EBV-encoded RNA (EBER, N = 37).

RESULTS

A third (38.8%, 109/281) of the ML patients with available clinical information had extranodal disease presentation. A total of 158 out of 174 biopsies selected for immunophenotyping were confirmed to be ML which were mostly (84. 8%, 134/158) non-Hodgkin lymphoma (NHL). Most (83.6%, 112/134) of NHL were B-cell lymphomas (BCL) (CD20+), of which 50.9%, (57/112) were diffuse large B-cell (DLBCL). Out of the 158 confirmed MLs, 22 (13.9%) were T-cell [CD3+] lymphomas (TCL) and 24 (15.2%) were Hodgkin lymphomas (HL) [CD30+]. Furthermore, out of the 60 FC analyzed ML cases, 27 (M:F ratio 2:1) were DLBCL, a slight majority (55.6%, 15/27) with activated B-cell like (ABC) and 45% (12/27) with germinal center B-cell like (GCB) immunophenotype. Overall, 40% (24/60) ML were aneuploid mostly (63.0%, 17/27) the DLBCL and TCL (54.5%, 6/11). DNA index (DI) of FC-analyzed ML ranged from 1.103-2.407 (median = 1.51) and most (75.0%) aneuploid cases showed high (>40%) cell proliferation by Ki-67 reactivity. The majority (51.4%, 19/37) of EBER ISH analyzed lymphoma biopsies were positive. Of the serologically tested MLs, 40.0% (14/35) were HIV positive, mostly with high (> or =40.0%) Ki-67 reactivity.

CONCLUSIONS

According to the 2001 WHO Classification, most subtypes are represented in Tanzanian ML. Extranodal presentation was common among MNH lymphoma patients who also showed high aneuploidy, tumor proliferation (KI-67) and EBER positivity. DLBCL was frequent and phenotype heterogeneity appeared similar to observations in Western countries suggesting applicability of established intervention approaches. HIV was apparently associated with high ML cell proliferation but extended studies are needed to clarify this.

Rare primary extranodal lymphomas: diffuse large B-cell lymphomas of the genital tract

Primary non-Hodgkin's lymphoma (NHL) of the genital tract is a rare entity. Etiology and pathogenesis of these NHLs are unknown, although there might be a possible association between chronic inflammation and lymphomas. The most common histological subtype is the diffuse large B-cell lymphoma. We report two cases of uterine lymphoma and one case of prostate lymphoma in this paper. The symptoms and the differential diagnosis are also discussed. Because of the low incidence, there is no widely accepted consensus on its treatment. We demonstrate that the rituximab and CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone; R-CHOP) chemoimmunotherapy is a good and tolerable treatment option in all cases. The two young patients are disease-free nowadays; the older patient with poor prognostic histological-type lymphoma relapsed in a short time and died after second relapse. A multicenter analysis is necessary to evaluate the long-term results of chemoimmunotherapy in these rare extranodal lymphoma entities.