The adjacent intestinal mucosa shows villous atrophy and crypt hyperplasia with marked intraepithelial lymphocytosis involving both crypt and surface epithelium (2). EATL types I and II cannot always be distinguished by morphology, as EATL type I may also present with monomorphic small-medium cells. Immunohistochemical

staining is usually helpful and the immunophenotype expected in EATL types and other intestinal T-cell lymphomas are summarized in Table 1. Lymphoma cells stain with CD8 and CD56 in the majority of EATL type II, but only a minority of EATL type I (3). Over 90% of EATL type I are associated with expression of HLA DQ2 or DQ8, versus only 30-40% of EATL type II (5). The differential #OSI-744 cost keyword# diagnosis for a tumor of small monotonous lymphocytes in the small intestine also includes certain B-cell lymphomas, Inhibitors,research,lifescience,medical primarily mantle cell lymphoma (MCL) (2), but these can be readily distinguished with immunohistochemical staining for pan-B cell antigens such as CD20. Among the other intestinal T-cell lymphomas, NK/T-cell lymphoma, nasal type, may present with small CD56+ lymphocytes, but unlike EATL Type II, these lymphomas are usually negative Inhibitors,research,lifescience,medical for CD8 and positive for Epstein Barr virus (13). Anaplastic large cell lymphoma (ALCL) usually consists of large lymphoid cells but rarely the majority of cells may be small to medium sized. The presence of

at least a few large anaplastic cells Inhibitors,research,lifescience,medical and the characteristic CD30 positive immunostaining reaction are helpful for differentiating these rare lymphomas from EATL type II (14). “NK-cell enteropathy” (15) and the related condition “lymphomatoid gastropathy” (16) are newly described entities in which atypical NK-cells (CD56+) infiltrate one or more GIT sites. Endoscopically there are multiple superficial, discrete, flat or hemorrhagic Inhibitors,research,lifescience,medical lesions, or small (<1 cm), patchy, superficial ulcers,

as opposed to the nodules, masses and strictures seen in lymphoma. NK-cell enteropathy causes few symptoms and has an uneventful clinical course (15). Finally, reactive lymphoid hyperplasia and CD should also be considered in the differential diagnosis of a dense infiltrate of small monotonous lymphocytes in the mucosa of the small intestine. Table 1 Isotretinoin Immunohistochemical findings in intestinal T- cell lymphomas and reactive lymphoid infiltrates@ This case highlights the unique diagnostic challenges posed by EATL type II. A high degree of suspicion, use of advanced diagnostic modalities and biopsy of grossly uninvolved site such as stomach may provide the best chance for prompt diagnosis. Acknowledgements We wish to thank Kirsten Boland, P.A. (ASCP) for help in autopsy prosection and Susan Reeves and Steven Conlon for expert help with gross and microscopic photography. Disclosure: The authors declare no conflict of interest.
Hepatocellular carcinoma (HCC) is a frequent complication of liver disease. HCC is the sixth most common malignancy worldwide (1).