Ovarian ectopic pregnancy: the role of complex morphopathological assay. Review and case presentation

Ovarian ectopic pregnancy (OEP) represents the rarest type of ectopic pregnancy, accounting for 1-3% of this pathology. The diagnosis of this pathology is challenging due to the non-specific clinical aspects and the ultrasound examination hampered by the lack of visible gestational sac in the presence of hematocele and hemoperitoneum. The purpose of the extended histopathological (HP) examination was to identify particular aspects of the OEP trophoblast and to highlight potential local ovarian modifications which can determine pregnancy fixation at this level. The patient presented local favorable conditions for intraovarian nidation, conditions confirmed by the HP classical examination and by the immunohistochemical evaluation. We identified, using classical Hematoxylin-Eosin, Masson's trichrome and Periodic Acid-Schiff (PAS)-Hematoxylin, necrotic hemorrhage, accentuated vascular thrombosis and high density lymphoplasmocytary infiltrate. These modifications increased local adhesivity and cell destruction through hypoperfusion. Anti-cluster of differentiation antibodies (CD34, CD38, tryptase) revealed the low number of intravillous vessels and the high number of macrophages and mastocytes involved in the local inflammatory process heighten. We identified the presence of trophoblast tissue in the ovarian structure using anti-cytokeratin AE1∕AE3 (CK AE1∕AE3)/anti-cytokeratin 7 (CK7) antibodies. The anti-alpha-smooth muscle actin (α-SMA) and anti-vimentin (VIM) antibodies displayed the density of myofibroblasts and intravillous stromal cells and with the aid of anti-progesterone receptor (PR) antibody, we identified the corpus luteum hormonal response in the OEP. The placental villosities present a blocked multiplication process at the anti-apoptotic B-cell lymphoma 2 (BCL2) protein, confirmed by the Ki67 cell proliferation and tumor protein 63 (p63) immunomarkers. Anti-neuron specific enolase (NSE), anti-calretinin and anti-inhibin A antibodies showed the particular aspects of the granulosa and internal theca cells, which may be involved in oocyte release blockage, intraluteal and extraluteal fecundation of the OEP.