Giant primary ovarian leiomyoma with cystic degeneration and calcification complicated by post-surgical acute pulmonary embolism in a 23-year-old nulligravida: A Case report

Abstract

Leiomyomas of primary ovarian origin are rare, benign, smooth muscle neoplasm constituting just 0.5-1% of the entire tumours of the ovary. They are often of small size, unilateral and occur predominantly in premenopausal women, usually diagnosed incidentally, aided by examination of the pelvis, post-surgery histopathological evaluation and confirmed by immunohistochemical staining. Additionally, primary ovarian leiomyoma of this size (with the greatest diameter of 29.5cm) has not been reported in the literature. It is not uncommon for large pelvic tumours to be associated with venous thromboembolic events (VTE). We hereby present a case of a 23-year-old nulliparous woman who presented with complaints of abdominal pain and swelling. Clinical examination revealed an abdominal mass of 34 weeks’ size. Abdominal ultrasonography showed an intra-abdominal mass that extended to the pelvis and a misdiagnosis of giant uterine leiomyoma was made. On laparotomy, a huge, right, well-encapsulated ovarian mass with a smooth surface was seen. Histopathological and immunohistochemical staining with desmin and vimentin confirmed it to be a giant primary ovarian leiomyoma with cystic degeneration and calcification. Additionally, the patient developed sudden onset of chest pain and breathlessness a day post-surgery for which urgent computed tomography pulmonary angiogram (CTPA) confirmed pulmonary embolism (segmental and post segmental regions bilaterally) and cardiomegaly. She was placed on low molecular weight heparin (Clexane) and oral warfarin which she responded well to. Indeed, primary ovarian leiomyoma should be considered an important differential in primary solid ovarian and pelvic tumours. Also, in large or giant pelvic neoplasms, anticoagulant prophylaxis should be considered to prevent untoward pulmonary embolism and its possible fatal outcomes.