Improved diagnostic accuracy in needle biopsy interpretation using molecular probes.

A prospective study of computed tomographically guided core needle biopsy samples was done to determine whether diagnostic accuracy could be improved in these specimens. Eighteen specimens from 16 patients were analyzed by routine and immunohistochemical stains on paraffin-embedded tissue and DNA probe hybridization on frozen tissue. Pathologic diagnoses based on light microscopy and immunostaining were malignant lymphoma (8), lymphoid tissue (1), malignant tumor (3), fibrous tissue (2), fatty liver and hepatic adenoma (2), giant cell tumor (1), and necrotic tissue (1). Analyzable DNA was obtained from nine specimens (50%); 67% of those yielding insufficient DNA (six of nine) were samples of benign liver, connective tissue, and necrotic tissue. Extracted DNA was hybridized with probes for JH, JK, CT beta, and bc/II. In 67% of analyzable cases (six of nine) the diagnosis of lymphoma was confirmed; in 33% the diagnosis of lymphoma or nonlymphoma was aided or resolved when the pathologic diagnosis was uncertain. Of the eight cases of lymphoma diagnosed by light microscopy, six were confirmed by genotyping and two yielded insufficient DNA for analysis. In all nine cases with sufficient DNA, hybridization identified B-cell monoclonality and confirmed or excluded follicular center cell origin, data not uniformly obtained with other studies. Molecular analysis can be a useful adjunct to routine methods of diagnosis of needle specimens, improving diagnostic accuracy in at least one-third of cases.