Lymphomatoidgastropathy mimicking extranodal NK/T cell lymphoma, nasal type: a case report.

Extranodal natural killer (NK)/T-cell lymphoma, nasal type, exhibits aggressive tumor behavior and carries a poor prognosis. Recently, lymphomatoid gastropathy with NK/T cell infiltration into gastric mucosa has been recognized as a pseudo-malignant disease which regresses without treatment. Because the conventional immunohistochemical criteria of lymphomatoid gastropathy is similar to that of extranodal NK/T-cell lymphoma nasal type, it is difficult to distinguish between the two conditions by histopathological evaluation only.