Cytofilaments and fibroblast junctions in the benign proliferation of connective tissue.

Benign proliferative patterns of connective tissue in the dermatofibroma are investigated. Neoplastic fibroblasts are similar to so-called myofibroblasts. However, filaments are the prevalent filamentous component, while microfilaments and microtubules are present in limited amounts. In addition, no junctions are observed between adjacent cells. Typical mast cells and histiocytes are rarely observed. This report adds evidence of the similarity between the neoplastic and inflammatory patterns of fibroblastic proliferation, and suggests that the proliferation of the active fibroblast of the dermatofibroma (viewed as an intermediate cell between the common fibroblast and the myofibroblast) does not lead to the development of a homodynamic system. It also confirms that this tumor may exist in a stable condition.