Papilloma

Papilloma (papilloma, s. fibro-epithelioma papillare), a collective term for various papillary tumors of different origins, mainly of the skin and mucous membranes (see Acanthoma, Wart, Vagina). P. consists of proliferation not only of papillae corii but also of the covering epithelium; both of these parts participate equally in the process. The epithelium in P. does not extend into the underlying connective tissue deeper than the adjacent epithelial covering. From a morphological standpoint, it is very difficult to distinguish true P. from proliferations resulting from inflammatory changes, especially since the presence of significant cellular infiltration in the connective tissue of the papillae does not resolve the matter, as it can be associated with any P. Nevertheless, besides true P., so-called papillary proliferations are distinguished separately, i.e., inflammatory hypertrophies of the skin and mucous membranes (in gonorrhea, syphilis, tuberculosis), depending on external inflammatory irritation. Papillary hyperplastic proliferations also include so-called secondary P., which form in chronic catarrhs, ulcers, scars, in cancerous tumors, many polypoid papillae of mucous membranes (nasal cavity, intestines, etc.), acute condylomas in gonorrhea, which however some dermatologists classify as true neoplasms. Some authors include most P. of the skin (so-called hard or horny warts) among P., which is not entirely correct, since these P. are mostly products of improper development. P. appear as tumors, most often solitary, ranging in size from a small elevation (wart size) to an apple or fist, sitting on a broad base or on a thin stalk. In most cases, papillary structure is also expressed in the external form of the tumor, giving it the appearance of warts, granular elevations, villi, polyps, cauliflower. The appearance of the connective tissue papillae and the epithelial covering of P. is variable. The papillae may vary in size, length, thickness, and shape (irregular, cylindrical, flask-shaped, pointed), simple or with complex tree-like branching and formation of so-called secondary papillae, from loose or denser connective tissue, with a larger or smaller number of blood vessels, sometimes dilated. The epithelium of P. is sometimes in the form of a thin layer, sometimes thick, covering sometimes several connective tissue papillae together, sometimes each individually. The character of the epithelium corresponds to the location of the tumor development, being sometimes multilayered flat, keratinizing and non-keratinizing, sometimes transitional, sometimes cylindrical. The ratio between the epithelial and connective tissue mass of P. also varies: much connective tissue with a thin epithelial covering and vice versa. Hard and soft P. are distinguished (p. durum et molle). Hard P. consists of keratinizing epithelium, often with signs of hyperkeratosis, and of dense connective tissue, observed in the skin, cornea of the eye, in mucous membranes covered with multilayered flat epithelium (oral cavity, pharynx, vagina, vaginal part of the cervix), as well as in the larynx and trachea. Dense P. do not bleed, rarely ulcerate. P. of the skin, usually known under the name of hard or horny warts, constitute the majority of all warts; their surface has cracks and tears, consists of keratinizing epithelium, there is limited hypertrophy of the connective tissue papillae. These warts are always of acquired, hyperplastic origin. Pigmented papillary birthmarks (naevus papillaris) belong to congenital warts. P. of the skin may occur in groups, forming warty, flat-tubercular, sometimes pigmented elevations (so-called papilloma neuropathicum unilaterale, papilloma lineare) and in some cases are located in accordance with the area of distribution of the skin nerves. Soft P. (p. molle) are observed on the mucous membrane of the urinary tract (renal pelvis, ureters, urinary bladder), uterus, fallopian tubes, less often in the stomach, intestines, bile ducts. Papillary proliferations in tumors, particularly in adenomas (e.g., papillary cystadenomas of the ovaries), P. of serous membranes, P. of the brain (more precisely of the brain ventricles, mainly the fourth), which have a villous appearance, covered with cubic or cylindrical epithelium, originating from the ependyma of the ventricles and from the choroid plexus, also belong here. The connective tissue in soft P. is loose, often edematous, taking on the character of mucous tissue (especially in P. of the nasal mucosa), rich in blood vessels, often dilated. Soft P. often bleed, sometimes detach (e.g., villi in P. of the urinary bladder). Multiple soft P. are not so rare in the mucous membrane of the urinary tract; sometimes P. occur in both paired organs simultaneously, e.g., P. of the surface of both ovaries. Most P. have a benign character, in many cases maintaining it to advanced old age; some P. persistently recur after removal, e.g., P. of the vocal cords, others show destructive growth and give metastases either from the very beginning or only later (transform into cancer), so-called malignant P. (p. malignum, s. carcinomatosum, s. carcinomatodes _T s. carcinoma papillare); more often these are P. of the urinary bladder, uterus, ovaries, nasal mucosa, larynx, pharynx. P. that develop from tar application, under the influence of X-rays, and sometimes with internal intoxications, e.g., arsenic, comparatively often transform into cancer. These forms are even proposed to be classified as precancerous dermatoses. Darier believes that all true P. belong precisely here. The special harm caused to the patient by benign P. depends partly on the location, e.g., P. of the vocal cords, partly on the tendency of soft papillomas to abundant bleeding (e.g., in P. of the urinary bladder with detachment of their villi). Papillomas of individual organs and tissues - see the corresponding Articles.