Fibroma

FIBROMA, fibroblastoma (fibroma, fibroblastoma), is a mature benign tumor consisting of connective tissue elements, namely fibroblasts, which constitute the parenchyma of the tumor, and connective tissue fibers with vessels, which constitute the stroma. A distinction is made between diffuse fibromas, or so-called fibromatosis, and circumscribed fibromas, in the form of separate nodules, tubercles, or polyps (nodular, tuberous, polypous fibroma). It is more correct, however, to separate the concept of diffuse fibroma from fibromatosis. In the latter case, we are dealing with multiple tumors, for example, in von Recklinghausen's disease; in the case of diffuse fibroma, the very character of the tumor's growth is meant: instead of the usual clear boundaries, there is a kind of infiltrating growth, i.e., a gradual transition of the tumor into the surrounding tissues. Such diffuse fibromas are sometimes difficult to distinguish from tumor-like hyperplasias of connective tissue (for example, diffuse fibromatosis of the mammary gland, elephantiasis, etc.). A distinction is also made between hard fibromas (fibroma durum, or so-called desmoid) and soft fibromas (fibroma molle). A hard fibroma has a whitish-shiny appearance and consists of closely grouped coarse bundles of collagen fibers; it is very poor in cells. Typical sites for its development are the skin, fasciae, tendons, muscles, periosteum, uterus, and ovaries. Keloid (see) is also considered a variety of hard fibroma. A soft fibroma has a whitish or pinkish appearance and is relatively rich in water, sometimes appearing edematous (fibroma oedematodes) or gelatinous. It is most often observed in the skin, mucous membranes, subserous tissue, and along the course of nerves. Sometimes a significant number of blood vessels are noted in a fibroma (fibroma teleangiektaticum, cavernosum), for example, in polypous fibromas of the nasal cavity or uterus, or lymph vessels (fibroma lymphangiektaticum). Often, the tissue of a fibroma undergoes significant degenerative-necrobiotic changes, e.g., of the mucous degeneration type (fibroma myxomatodes) or cystic decay (fibroma cysticum). In connection with these changes, petrification of the fibroma tissue is possible (fibroma petrificans). Sometimes ossification of a fibroma is noted (fibroma ossificans). Fibromas with lime deposits, as well as with the development of bone, are especially often observed in the uterus, where they are apparently a stage in the development of fibromyomas. Fibromas usually possess expansive growth, with the exception of the above-mentioned diffuse forms, which nevertheless remain benign formations. A peculiar type of growth is noted in so-called plexiform fibromas (fibroma plexiforme), where the tumor tissue spreads and branches along the course of blood vessels, nerves, or the excretory ducts of glands, for example, in the mammary gland. Among the mixed forms of fibroma, fibrolipomas (skin, kidneys), fibromyxomas, and fibromyomas (uterus) are most frequently encountered. In glandular organs, a frequent tumor is fibroadenoma, e.g., in the mammary gland; see also Neurofibroma, Neurofibromatosis. Treatment of fibroma is surgical. I. Davydovsky.