We describe a rare clinical case: onset of acute neurological symptoms suggestive of a pesudostroke, caused by an imbalance in cerebral blood flow as a result of internal carotid artery compression by an enlarged lymph node secondary to metastases from a disseminated non-gestational mediastinal choriocarcinoma. This was accompanied by decompensation due to paraneoplastic coagulopathy.

Objective: to estimate the peculiarities of cellular infiltrate of endometrioid ovarian cysts (EC) at various morphological stages of their formation (during evolution). Material and methods. 57 patients with histologically verified diagnosis of ovarian EC were studied; morphologically, endometrioid cysts were divided into types conventionally designated as "immature", "mature" and "old". Inflammatory cells were counted in the EC wall. Results. In the tissues of the "immature" EC, the underlying fibrous layer is represented by loose connective tissue, with a small number of granulocytes, single siderophages. An increase in the number of granulocytes in the fibrous layer along the border of the EC tissue (/-/=17.10; p<0.001; "young" — 8566.0 "mature" — 9719.0), as well as an increase in the number of lymphocytes in the stroma of the endometrioid lining (/-/=38.03; p<0.001; "young" — 6579.0; "mature" -11156.5) leads to a gradual compaction of the fibrous layer, that is the onset of a stage of "mature" endometrioid cyst. Violation of the blood supply to heterotopia leads to depletion of the macrophage pool due to the polarization of macrophages with an increase in the number of siderophages, that adversely affects the state of endometrioid heterotopia in the form of a decrease in almost all cells types: lymphocytes ofthe endometrioid stroma lining (/-/=38.03; p<0.001; "mature" — 11156.5; "old" — 6574.5); neutrophils of the endometrioid stroma lining (H=13.25; p=0.001; "mature" — 9199.5; "old" — 6136.0), neutrophils ofthe underlying fibrous layer (/-/=17.10; p<0.001; "mature" — 9719.0; "old" — 6025.0). Conclusion. The obtained data allow us to talk about the formation of a morphological picture ofthe "old" EC. The change of an acute inflammatory reaction to a chronic one with an outcome in sclerosis facilitetes hypoxia, being the main modulators of the evolution ofthe ovarian EC.