No abstract

Although the gastrointestinal (GI) tract is the most common site of primary extranodal lymphomas, the lineage of these tumors has been controversial. The authors used paraffin-reactive antibodies detecting markers of B-, T-, histiocytic, and epithelial cells to study 34 non-Hodgkin's lymphomas of the GI tract for which unequivocal frozen-section immunophenotypine was available as a control to determine whether these antibodies are reliable in the study of these tumors. Frozen-section studies revealed 31 tumors of B-cell origin and three T-cell tumors. Paraffin-reactive antibodies confirmed B-cell lineage in 28 of the 31 cases, with equivocal results in the remaining three. Only one of the T-cell lymphomas was identified in paraffin studies. Our results indicate that paraffin-reactive antibodies can reliably identify most B-cell lymphomas in the GI tract but may be unreliable in the detection of lymphomas of T-cell origin.