Ovarian schistosomiasis: challenges of a neglected ectopic involvement of blood flukes. Case report and review of literature

Abstract

Introduction: Female genital schistosomiasis (FGS), infection of Schistosoma spp. trematode in the gynaecological apparatus, is the most neglected sexual and reproductive health condition in sub-Saharan Africa with an estimated of 20-120 million cases. The ectopic entrapment of Schistosome eggs after oviposition can occur in 0.5% of cases in fallopian tubes and ovaries.

The case: We report a case of 38-years-old woman assessed for a 10 year history of infertility. On ultrasound, multiple cystic formations were observed in the ovary. Histology after oophorectomy to exclude malignancy showed granulomatous formations surrounding Schistosoma spp. eggs in proximity of corpus luteus and haemorragicum.

Discussion: Ectopic Schistosome oviposition, seen in the ovary and fallopian tubes as in our case, can be a potential cause of reproductive organ damage and complications such as infertility, ectopic pregnancy, miscarriage, premature birth, low birth weight, and even maternal death.

Conclusions: More studies are needed on ovarian FGS and its impact on women fertility to guide specific interventions targeting vulnerable population of childbearing age, contributing to the NTD WHO 2030 aim of eliminating schistosomiasis as a matter of public health.

Keywords: infertility; ovarian cyst; ovarian schistosomiasis; sub-Saharan Africa.

Figure 1.

(A) Venous drainage anatomy favouring Schistosoma’s eggs reaching the ovary. Utero-vescical plexus and inferior rectal veins drain in the internal iliac vein. The superior rectal vein drains in the superior mesenteric vein and portal system; the ovarian plexus drains in the vena cava on the right, in renal vein on the left. Contiguity between venous vessels and plexus and depletion of valves in these vessels in these regions favour Schistosoma eggs (S. haematobium but also S. mansoni) spreading to the female genital tract. (B) pictorial view of the ovary section. Granuloma’s around Schistosoma spp eggs (arrow) are present. (C) Haematoxyline and eosin 400X. (D-H) histology sections-haematoxyline and eosin of the ovary showing Schistosoma eggs surrounded by granulomatous reaction. (G) original magnification. The picture is original work by co-author Valeria Silvestri.

Figure 2.

Pathophysiology of infertility in FGS involving the ovary. Granuloma formation, impairment of hormonal homeostasis due to parasitic oestrogen synthesis, DNA damage, consequences of surgery can all lead to infertility in this specific setting.