Infantile digital fibromatosis: Immunohistochemical and ultrastructural observations of cytoplasmic inclusions

Publisher Website
Google Scholar
Abstract
Using antibodies against actin, tubulin, and intermediate filaments immunohistochemical studies were performed on a nodule from an 8-month-old girl with infantile digital fibromatosis. None of the antibodies significantly stained the cytoplasmic inclusion bodies, which were a distinct morphologic feature of this fibromatosis. This result is in contrast to a previous report that stated that the inclusions were composed chiefly of actin filaments. In ultrastructural term, the tumor cells were morphologically consistent with cells in myofibroblasts. The inclusions consisted of packed fibrillar and granular substances. Cultured cells containing inclusions identical to those seen in the original tumor mimicked a growth pattern in vivo. Scanning electron microscopy showed that cultured cells had thin foot processes containing many microspikes. Detergent-treated preparations examined by transmission electron microscopy displayed a microtrabecular meshwork characterized by three, major cytoskeletal domains with many actin cables. Cultured cells showed a normal karyotype.