[Solitary fibrous tumor of the kidney].

Solitary fibrous tumor is a rare mesenchymal neoplasm, the most common localization of which is the pleural cavity, but the tumor can also affect other organs. This neoplasm with localisation in the kidney was first described only in 1996. Solitary fibrous tumor accounts for 0.2% of all kidney neoplasms and is an exceptional phenomenon. Currently, there is no generally accepted theory explaining the etiology and pathogenesis, probably, its development is a multifactorial process including a combination of genetic, epigenetic and external factors. Despite the lack of unambiguous opinion on the nature of the neoplasm, the spectrum of molecular abnormalities in this tumor has been sufficiently studied. The literature presents a limited number of publications devoted to this pathology, in this regard it should be noted that in routine practice, the morphological picture may not always be so unambiguous and require the pathologist to conduct differential diagnostics with a fairly wide range of tumors. Given the rarity of this disease, we would like to share a description of our own clinical observation demonstrating the possible difficulties of morphology diagnostics.