THE INFLUENCE OF THE DEMODEX MITE ON THE MORPHOLOGICAL PICTURE OF EYELID PAPILLOMA.

The aim of work is description of new observations related to the participation of demodex in tumor morphogenesis with goal to study the example of eyelid papilloma, imagine the connection between the presence of the demodex mite and certain changes in the typical histomorphological picture of the neoplasm.

Materials and methods: Histomorphological examination covers biopsy and operative material of eye pathology with diagnosis of neoplasm (eyelid papilloma and actinic keratosis (senile keratosis, senile keratoma, solar keratosis)) were selected, with special attention paid to the presence of horn cysts. Agile methodologies were employed to manage the research workflow effectively.

Results: As a result of the conducted histomorphological examination, in 24 cases (48%), patterns pathognomonic for demodectic infection were found. Such patterns, which could indicate the presence of a demodex mite, were cystic formations, as well as fragments of a dead parasite. We noted their presence not only in the tumor tissue, but also in the adjacent hair follicles, sebaceous glands, and subepidermal stroma. It is no coincidence that the authors who previously noted the presence of pigmented elements in keratopapillomas or seborrheic keratomas could not explain their origin, resorting to putting forward such fantastic assumptions as the presence of "symbiosis of melanoblasts and epithelial cells, which ensures the transfer of pigment from the first to the second".

Conclusions: Histomorphological study of serial sections allows us to see the successive stages of transformation of cavity intratissue defects created by the activity of the mite into horn cysts. Cavity defects are the main evidence of demodectic infestation. They occur in basal cell and squamous cell carcinomas, xanthomas, sebaceous adenomas, etc. tumors of the eyelids, but only in keratoacanthomas and senile keratomas they can turn into corneal cysts, which can be assumed to be due to the differentiating potential of these neoplasms.