Natural killer-like T cell lymphoma of the small intestine: report of a case.

We report the case of a 77-year-old Japanese man with natural killer (NK)-like T cell lymphoma of the small intestine diagnosed after an emergency laparotomy for perforated peritonitis. Immunohistochemical staining of the tumor showed that the patient had CD3+ CD8+ CD30- CD56+ CD68- CD79a- UCHL-1+ EMA- LMP-1 NK-like T cell lymphoma. The patient had a history of hepatocellular carcinoma (HCC) and was also diagnosed with T cell non-Hodgkin's lymphoma associated with T cell receptor (TCR) reconstruction in the Jgamma chain. Intestinal T cell lymphoma is uncommon and very few cases of CD56+ T cell lymphoma, otherwise known as NK-like T cell lymphoma, have been reported. The patient did not have a history of gluten-sensitive enteropathy (celiac disease). Multiple lesions appeared within months after the initial operation and his condition deteriorated rapidly. We think that this patient probably had NK-type granular lymphocyte-proliferative disorder (NK-GLPD) because the percentage of CD16+ CD56+ cells among peripheral blood mononuclear cells was elevated, at 21%. We report this case to help elucidate the relationship between underlying digestive organ disease and the development of intestinal NK-like T cell lymphoma. An accumulation of other such cases is needed to determine the etiology of this disease.