Bibliothek

Notizen: Aims:  Most primary gastrointestinal lymphomas are of B-cell origin and T-cell origin is very rare. Recent studies have suggested that human T-cell lymphotrophic virus type 1 (HTLV-1) may be involved in the development of primary gastric T-cell lymphoma. We analysed 31 patients with primary gastric T-cell lymphoma in south-west Japan, an area endemic for HTLV-1, and determined their phenotypes, genotypes, and HTLV-1 status.Methods and results:  Here we present 31 cases of primary gastric T-cell lymphoma in a HTLV-1-endemic area in Japan and analyse the clinical status, histology, phenotype and virus status. The median age at onset of primary gastric T-cell lymphoma was 57 years with a gender ratio of M:F = 1.58:1. Six of the 31 primary gastric T-cell lymphoma cases had HTLV-1 proviral DNA (five males, one female), nine of the 31 cases were positive for anti-adult T cell leukaemia antibody, without examination of HTLV-1 proviral DNA (five males, four females), eight were non-HTLV-1-associated primary gastric T-cell lymphoma (four males, four females) and the other eight cases were unknown. Primary gastric T-cell lymphoma usually presented as a large ulcerated tumour at the corpus to the antrum and histologically consisted of anaplastic large cell type (n = 2), pleomorphic large cell type (n = 3), pleomorphic medium and large cell type (n = 14), pleomorphic medium cell type (n = 11), and angioimmunoblastic T-cell lymphoma type (n = 1). There were no clear macroscopic and microscopic differences between HTLV-1-associated and non-HTLV-1-associated primary gastric T-cell lymphoma. Most patients died within 2 years of diagnosis, and both types of primary gastric T-cell lymphoma (with and without HTLV-1) were associated with poor prognosis. Cytotoxic marker analysis showed that HTLV-1-associated lymphomas were negative for TIA-1, while non-HTLV-1-associated lymphomas were positive for TIA-1.Conclusions:  Our results suggest that in HTLV-1-endemic areas, patients with HTLV-1-associated primary gastric T-cell lymphoma should be managed carefully and that TIA-1 seems to be useful for identifying the aetiology of this lesion.

Notizen: Accessory cell tumour: a clinicopathological study of 16 aggressive tumours containing EBV-positive Hodgkin and Reed–Sternberg-like giant cells Aims: Lymph nodes contain non-lymphoid accessory cells including follicular dendritic cells and interdigitating dendritic cells. Functionally, these cells belong to the category of immune accessory cells involved in antigen presentation to B or T-lymphocytes. Neoplastic proliferation of these cells is very uncommon. We present here the clinicopathological features of 16 cases of accessory cell tumour. Methods and results: We performed electron microscopic and immunohistochemical examinations, and used in-situ hybridization for EBV-encoded RNA (ISH-EBV) to detect the EBV genome in 11 cases, and Southern blot analysis to assess EBV clonality in two cases. Tumour cells were composed of oval-to-spindle cells arranged in diffuse, vague storiform, fascicular and sometimes whorled patterns in a background of small lymphocytes. In all cases, binucleated or multinucleated Hodgkin and Reed–Sternberg-like giant cells were encountered. Staining for CD68 was positive in all cases. CD21, CD35, Ki-M4p, Ki-FDC1p, and S100 exhibited variable reactivity. ISH-EBV yielded positive labelling in seven of 11 cases, of which five exhibited EBV only in Hodgkin and Reed–Sternberg-like giant cells. Southern blot analysis showed clonality of EBV terminal repeats (EBV-TR) in the two cases examined. Electron microscopic examination showed that many of the tumour cells had numerous interwoven long villous cell processes connected by occasional desmosomes. Many tumours were very refractory to chemotherapy and radiation, with a few exceptions, and half of the cases classified initially as stage IV. A short survival time, of 10 months or less, was observed in seven of 16 patients. Conclusions: Our study identified more aggressive behaviour of accessory cell tumours. Our results suggest that EBV may potentially induce activation of accessory cells to form Hodgkin and Reed–Sternberg-like giant cells, which correspond with poor prognosis.