Detection of clonal immunoglobulin heavy chain gene rearrangements by polymerase chain reaction in scrapings from archival hematoxylin and eosin-stained histologic sections: implications for molecular genetic studies of focal pathologic lesions.

Using a simple scraping technique to obtain DNA directly from archival hematoxylin and eosin-stained slides, we successfully amplified clonal immunoglobulin heavy chain gene rearrangements (IGR) from lymphomatous infiltrates, as small as 1 mm2. The fragments amplified by the polymerase chain reaction (PCR) were identical in size to those from corresponding whole unstained sections freshly cut from the paraffin-embedded blocks. Using this technique, we detected clonal IGR from the scraping of a small lymphomatous nodule in the colon, although no amplified fragments were detected from the whole section. Furthermore, we demonstrated that two morphologically different areas in a case of B-cell lymphoma have identical amplified fragments. It is important that no amplified fragments were detected in scrapings from adjacent nonneoplastic areas. Although DNA recovered from scrapings was partially degraded, fragments as large as 725 base pairs were successfully amplified from a slide stored more than 11 years. This technique thus allows detection of clonal IGR in tissues focally involved by B-cell lymphoma and molecular genetic studies of focal pathologic lesions as an alternative to in situ hybridization or in situ PCR. Finally, this technique can be applied to archival slides when tissue blocks are not available.