Ovarian fibromatosis (OF) is a rare non-neoplastic condition, more frequent in young females and characterised by ovarian enlargement with proliferation of collagen-producing spindle cells in the stroma. It usually presents with abdominal pain, menstrual disorders or as a solid mass. Hirsutism and virilisation are possible. The relevance of this subject remains in the usual misdiagnosis as a malignant tumour, which may lead to unnecessary oophorectomies. We report the case of a 17-year-old female who presented with acute intense pain in the right iliac fossa and vomits. On examination, she complained of intense pain without any signs of peritonism. An abdominal ultrasound was performed, finding an enlarged right adnexal containing a heterogenic cyst without flow to the ovary. A Pfannenstiel laparotomy showed a right ovarian torsion. The haemorrhagic cyst was drained and the ovary was detorsed. Bilateral ovarian biopsies were performed as both ovaries showed an indurated and cerebroid surface, suggestive of malignancy. Tumoural markers were negative. Histological examination confirmed OF. After 3 months, the magnetic resonance imaging showed an enlarged right ovary with a fibrous capsule surrounding both ovaries. In conclusion, OF can also be found incidentally in the context of an ovarian torsion. Since its appearance may be dismissed as malignant, it is important to recognise it and remain conservative. Biopsies can be taken to make the differential diagnosis.
Keywords: Ovarian fibromatosis; ovarian torsion; paediatrics.