Abstract
Background: Among primary intestinal lymphomas, CD-56-positive aggressive natural killer (NK) cell lymphoma is a rare disorder. We report a case of NK cell lymphoma arising in the small intestine.
Case: A 49-year-old Japanese male presented with abdominal pain due to tumor perforation. Intraoperative cytological specimens in the ascites contained scattered medium to large-sized atypical lymphoid cells with an inflammatory background. On Papanicolaou stain, the tumor cells had a moderate amount of amphophilic cytoplasm. Their nuclei were round or slightly indented with a thick nuclear membrane, containing multiple small but conspicuous nucleoli situated at the nuclear membrane and finely dispersed chromatin. Giemsa-stained specimens revealed numerous intracytoplasmic azurophilic granules. Based on histological examination of the surgical materials including immunohistochemical analysis, we finally confirmed this case to be NK cell lymphoma.
Conclusions: Giemsa-stained cytology specimens are informative when dealing with NK/T lymphoproliferative disorders, because azurophilic granules are easily identified in the cytoplasm of variable proportions of tumor cells. This feature, however, could not be appreciated in the Papanicolaou-stained specimens.
