Rodent Ulcer

RODENT ULCER, a term used by some authors to denote an ulcerating, slowly spreading epithelioma of the facial skin, while others use it as a synonym for basal cell epithelioma, flat skin cancer, superficial epithelioma, cancroid, etc. Characteristic of this group of skin cancers is the many-year, very slowly progressive course, absence of metastases and cachexia, comparative ease of therapy, and predilection for certain parts of the face. All these clinical features distinguish rodent ulcer from the much more malignant infiltrating and papillomatous cancers, but it should be kept in mind that flat cancer can, over time, transform into a deeply penetrating form. Superficial and deeply penetrating cancers occur approximately equally frequently according to surgical statistics, but in dermatological practice, superficial cancer predominates. The disease affects almost exclusively elderly people over 50 years of age; of 291 cases, Grigoriev saw only 3 younger than 30 years. Men and women get sick approximately equally often (Shanin). More or less obvious etiological factors can be detected in only a small number of cases. Of 175 cases of various skin cancers that passed through the Oncological Institute in Leningrad, in 65 the etiology remained unknown, in 34% the development of cancer was preceded by acne, ulcers, and warts, in 20% trauma was established, in 9% burns, in 5% lupus. The possibility of the influence of professions involving the use of carcinogenic materials (tar, resins, aniline, etc.) on the development of rodent ulcer cannot be disputed, but the weight of these factors has not yet been clarified. Histologically, the new-formed tissue consists of epithelial, branching and anastomosing strands, originating from the proliferation of the interpapillary processes of the epidermis, as well as from the epithelium of hair follicles, sebaceous and sweat glands. The cells forming these strands are small, stain well, have no tendency to keratinization, and resemble the basal cells of the epidermis, which is why Krompecher proposed the name basal cell epithelioma. The stroma of the new growth consists of fibrous tissue. Often, more or less significant infiltration is noted, and among the cells of the infiltrate, plasma cells can be observed in large numbers. The histological picture is able to modify during the process, acquiring a mixed (baso-spinocellular cancer) or spinocellular character. This circumstance makes the histopathological classification of skin cancers conditional and forces some authors to prefer a clinical classification, which however must also take into account the possibility of the transition of benign flat cancer into a more malignant infiltrating form. Course and symptoms. The favorite localization of rodent ulcer is the part of the face located above the level of the mouth line, especially the area of the outer angle of the palpebral fissure and the adjacent part of the cheek and temple, but it can also develop on any other area of the skin. The initial lesion appears either on healthy skin or sometimes is associated with a pre-existing senile keratosis and is characterized by the development of clustered, somewhat dense, pearly-white nodules the size of a millet seed and not accompanied by subjective sensations. After months, and sometimes years, the initial lesion gradually increases and changes. In some cases, central atrophy or sclerosis occurs, or only scarring takes place, and only at the periphery is the lesion bordered by nodules, or most often, by a pearly-white, solid or lace-like roller (flat scar cancer); in other cases, the surface of the plaque flattens and ulcerates, becoming covered with crusts (ulcerative-scarring flat cancer). The ulceration can be deep, involving the entire thickness of the skin, and slowly spread serpiginously, and in these cases the roller at the periphery is usually absent (true rodent ulcer of Jacob). Any of the listed forms, with sufficient duration of the course, can lead to extensive deep destruction and disfigurement (terbrans epithelioma). Common to all forms is the long absence of metastases and even the absence of regional involvement of the glands. Thus, the malignancy of rodent ulcer has mainly a local character, but the destruction of parts of the face important for nutrition and respiration affects the general condition, and in addition can give rise to secondary infection and bleeding. Most often, rodent ulcer is solitary, but cases occur where the number of foci reaches several dozen. In such cases, they are usually located not only on the face but also on the trunk, and sometimes only on the latter. Diagnosis presents no difficulties and is based on the duration of the course and the presence of the characteristic peripheral roller and nodules. Both of these features allow rodent ulcer to be distinguished from tuberculous syphilid. Confusion with lupus can be easily avoided, as there is nothing similar to the lupous nodules. It is important to timely recognize the initial forms and distinguish them from senile keratoses. The prognosis, with timely therapy, is incomparably more favorable than that of cancer of internal organs (84% recovery according to data from the Oncological Institute). Treatment aims at the radical removal or destruction of the new-formed tissue and consists in surgical intervention where possible, or in x-ray therapy (doses of at least 5 HED with filter) and radiotherapy (Jordan). Very good results are obtained by freezing with carbon dioxide snow (Morozov), and the freezing should continue for 2-5 minutes under considerable pressure. Prophylactically, it is very important to widely promote early seeking of medical help.