Gastric "pseudolymphoma" with restricted light chain expression in a patient with obscure gastrointestinal blood loss.

We present a case report of a gastric "pseudolymphoma" (GL) that exhibits restricted light chain expression and, therefore, illustrates the dilemma encountered when histologically benign lesions have phenotypic abnormalities suggesting malignancy. For many years this lesion has been considered usually benign; however, recent reports such as this one demonstrate immunologic signs of monoclonality in an otherwise histologically benign lesion. This finding challenges our assumptions as to the nature of this lesion and our definition of cancer. The lesion also displays "Castleman-like" features (angiofollicular hyperplasia) as well as "common inflammatory" germinal centers. In addition we briefly review the literature.