Malignant eccrine poroma: causes, symptoms, diagnosis, treatment

Malignant ecrine powder (syn: cancer cell, epidermotropic ecrcine carcinoma, ecrcine carcinoma) is a very rare tumor that usually occurs against the backdrop of a long-standing eccrine powder or de novo on unchanged skin. It occurs, as a rule, in the elderly, the average age of patients is 67 years, equally common in men and women. In 45% of cases, the localization of the tumor on the skin of the lower limbs, 20% - on the skin of the trunk, 15% - on the head and 10% - on the upper limbs. Occasionally, the cancer cell may have unusual localization, in particular on the nail bed against the background of radiation dermatitis, or occur in a patient suffering from pigmentary xeroderma.

Symptoms of a malignant ecrine powder

Clinically manifested in the form of an exophytic node, the surface of which is eroded, on a wide base, 1-5 cm in diameter. The growth is relatively slow, with a delayed metastasis in the regional lymph nodes of 30%. In some cases metastasis is accompanied by lymphostasis.

Pathomorphology is characterized by proliferation of basaloid cells in the epidermis and complexes of these cells in the dermis. The intra-epidermal component, in contrast to the benign analogue, is represented by focal clusters of large cells with hyperchromic, polymorphic nuclei, mitosis figures and foci of necrosis. Sometimes, in the thickness of the accumulations of tumor cells, proto-shaped structures are seen. Intradermal complexes consist of light cells with large atypical nuclei containing large-dispersed chromatin. Among the cellular growths are found slit-like or small-cystic cavities, as well as orthokeratotic "horny pearls". On the periphery of tumor strands, an inflammatory infiltrate is formed. In the lymphatic vessels of the dermis, tumor cells are sometimes found. In the primary cancer cell, the following histological variants can be observed at different frequencies: the pagetoid cell type in the hyperplastic epidermis; cells with a light cytoplasm with a high content of glycogen; foci of mucus in the stroma; perineural infestation. In the light cell variants, low phosphorylase activity was detected, which is associated with a deficiency of this enzyme in diabetic patients, which in turn leads to the accumulation of glycogen in the tumor cells. Ultrastructural studies confirmed the flat-epithelial nature of cells with the presence of tonofilaments, interweaving cytoplasmic villi, compacted contacts and intra-cytoplasmic lumens.

Histogenesis of a malignant ecrinic powder. Porocarcinoma is a malignant tumor with a differentiation of structures characteristic of the intra-epidermal section of the duct of the eccrine sweat gland. In the immunohistochemical study, duct structures and keratinization foci produce a positive reaction with carcinoembryonic hypertension, with AH epithelial membranes, and with alpha-lactthalalbumin antigen.

[1], [2], [3], [4], [5], [6]