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Metatype Skin Cancer: Causes, Symptoms, Diagnosis, Treatment
Last reviewed: 23.04.2024
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Metatypical skin cancer (syn: basal cancers, mixed cancers, intermediate carcinoma) can develop on unchanged skin, but often occurs against a pre-existing basal cell, especially after X-ray therapy. The clinical manifestations of metatypeic cancer in most cases do not differ from the clinical picture of basal cell and usually correspond to its tumor and ulcerated forms. Metatypeic cancer is observed more often in old age in males. Like basal cell carcinoma, metatypic cancer is often seen on the face, but it can also be in other places where basal cell carcinoma does not occur (for example, the skin of the limbs).
[Pathomorphology of metatype skin cancer
Often has much in common with that of basal cells. Almost always, as in basal cell, the connection of tumor elements with the epidermis is revealed. Among the histological forms of metatypeic cancer, a solid type of tumor predominates with the presence of morphine-like structures or sites with adenoid differentiation, however, morphine-like and adenoid tumor variants can be observed separately. On this basis IA. Kazantsev et al. (1983) identified a solid, morphine-like and mixed histological variants. In all these species, the tumor consists of cells resembling basaloid, but somewhat larger and with a more pronounced rim of the eosinophilic cytoplasm. The characteristic "palisade-like" arrangement of cells along the periphery of tumor complexes, as observed in basal cells, is retained only in places or completely absent. On this basis, metatypic cancer can be identified in cases where it occurs against a pre-existing basal cell, which is observed quite often.
Against the background of solid, adenoid and morphine-like types, as a rule, there are keratotic foci resembling "pearls" in squamous cell carcinoma. The abundance of histological variants, their similarity to basal cell make diagnosis difficult. For more accurate diagnosis, methods of assessing the mitotic regimen of the tumor have recently been used. I.A. Kazantsev et al. (1983), studying the mitotic regime of metatypeic cancer and basal, showed that mitotic activity in metatypeic cancer is 2 times higher than in basalioma.
A characteristic feature of metatype cancer in all the observations was the emergence of multipolar and monocentric mitoses typical for all malignant tumors, ana- and telophase bridges, and three-group metaphases, which are absent in basaliomas.