High grade, synchronous colon cancers after renal transplantation: were immunosuppressive drugs to blame?

Recipients of renal transplants are known to have an increased incidence of cancer, which is believed to be related to the use of immunosuppressive drugs used to prevent rejection. Although the risks of lymphoma and Kaposi's sarcoma are clearly increased in this setting, the association with colon cancer is controversial. We report a 44-yr-old woman, 20 yr post-renal transplant, and with no family history of colorectal cancer or polyps, who was found to have synchronous, poorly differentiated colon cancers associated with extensive abdominal lymph node, bone marrow, and bone (skull) metastasis.

Enhancement of histological detail using metanil yellow as counterstain in periodic acid Schiff's hematoxylin staining of glycol methacrylate tissue sections.

Histological detail in sections from tissues embedded in glycol methacrylate was improved by counterstaining PAS/iron-hematoxylin stained sections with a dilute solution of metanil yellow. The addition of the counterstain increases contrast in tissue sections and highlights PAS-positive entities. The staining protocol provides sharp definition of tissue morphology, differentiates cell types and other tissue components and does not produce background staining.