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Epidermal cyst: causes, symptoms, diagnosis, treatment
Last reviewed: 20.11.2021
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The epidermal cyst (blue infundibular cyst) is a developmental defect. It is a slowly growing, dermo-hypodermal nodular formation, localized on the scalp, lime, neck and trunk. It can be of various sizes, but usually its diameter does not exceed 5 cm, has round or oval outlines. Multiple cysts are observed in Gardner's syndrome, combined with fibromas, desmoid tumors, skull bones osteomies and prone to malignant polyposis of the rectum.
Pathomorphology. The epidermal cyst wall is similar in structure to the epidermis, the contents are lamellar keratin and cholesterol crystals. The wall of long-existing cysts is atrophic, lined with only 2-3 layers of epithelial cells. If the wall is damaged, a granulomatous reaction occurs with the formation of giant cells of foreign bodies, as a result of which the cyst is completely destroyed and resorbed. In some cases, the inflammatory reaction can cause pseudoepitheliomatous hyperplasia of the remaining parts of the epidermis.
Histogenesis. According to some authors, epilormal cysts are histogenetically associated with the epithelium of the infundibular part of the hair follicle, as well as the intra-epidermal sections of the ducts of the occlusal glands. Electron microscopy shows that the epitheliocytes that make up the cyst wall contain aggregated tonofilaments and keratogialin granules, as in the normal epidermis. In places of keratinization of epithelial cells, loss of desmosomes is observed.