Paediatric T-cell lymphoma of the appendix: a case report

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1302380563830412 webcite.The specification of non-Hodgkin lymphoma (NHL) in the “WHO Classification 2008” is based on recent progress in immunohistochemical and genetic analysis and clinical findings, including prognostic data [1]. Among extranodal NHLs, the alimentary tract is the most frequently affected site [1,2]. In the small intestine, diffuse large B-cell NHL (DLBCL) is the most common subtype of lymphoma, followed by mucosa-associated lymphoid tissue (MALT) lymphoma in the elderly, while Burkitt’s lymphoma is the predominant childhood NHL. Appendiceal involvement is extremely rare, constituting less than 1% of all small- and large-intestinal NHLs [2,3]. About 50 cases of appendiceal NHL have been previously reported, but immunohistochemical and genetic examinations have been performed in only a limited number of recent cases, including two T/natural killer (NK)-cell NHL cases [2-5]. Among intestinal T/NK-cell NHLs, enteropathy-associated T-cell lymphoma (EATL) has been frequently reported in the elderly [1,6-8]. Type I EATL is a CD4- and CD8-negative and CD30-positive large-cell lymphoma associated with coeliac disease, and is seen in northern Europe and the United States. Type II EATL is a CD56-positive and CD8-positive or -negative medium-sized lymphoma that is less strongly associated with coeliac disease. There are several reports of nasal-type NK-cell lymphomas with Epstein-Barr virus (EBV) infection in intestine and colon, which are usually encountered in the elderly and rarely in children [7,9]. The present case is a CD3-, CD4- and TIA1-positive and CD30-negative (Th1) large-cell lymphoma without EBV infection. CD4-positive T/NK-cell lymphoma has occasionally been reported in the stomach, but is rarely seen in the intestine [10,11]. The intestinal bacterial florae, Helicobacter pylori and Campylobacter jejuni, may be initiators of abnormal lymphocyti