Imaging findings of granulosa cell tumour of right ovary with rupture and torsion presenting as acute abdomen

Description

A multiparous woman in her late 40s presented to the gynaecological outpatient department with sudden right iliac fossa pain, vomiting and one febrile episode. She had regular menstrual cycles, with her last period 10 days prior to the presentation. On examination, the patient was pale, with abdominal distension and right-sided tenderness. A firm pelvic mass was palpated, reaching up to the infraumbilical level. Pelvic examination showed bilateral fornix fullness. Laboratory testing revealed low haemoglobin of 48 g/L, an elevated total leucocyte count and an increased Cancer Antigen-125 level measuring 187 U/mL. Preoperative hormonal profiles like inhibin, oestrogen, Luteinizing hormone and Follicle-Stimulating hormone were not done. The patient was referred from another institution with an ultrasound report suggesting a large multiloculated right adnexal mass with ascites, prompting an MRI to further evaluate the lesion.

The MRI showed a predominantly T2 heterointense mass lesion in the right adnexa measuring ~16×14×11 cm, with T2 hyperintensities within denoting cystic/necrotic regions (figure 1A,B). The right ovary was not visualised separately, and a twisted vascular pedicle supplying the mass was observed, indicating torsion (figure 1C,D). There were also moderate ascites on (figure 1A) gradient echo images showed intralesional blooming and peritoneal fluid, indicating haemorrhage and haemoperitoneum. T1 sequences revealed hyperintensities within the mass, suggesting subacute haemorrhages (figure 2A,B). The left ovary, uterus and endometrium appeared unremarkable, with few cervical nabothian cysts. Incidentally, a horseshoe kidney was noted (figure 3A,B). Imaging features favoured the diagnosis of an ovarian neoplasm with torsion and haemoperitoneum, leading to emergency laparotomy. Intraoperatively, the adnexal mass of 20×15 cm was noted, showing areas of rupture, torsion twice around the pedicle and 1000 mL haemorrhagic ascites (figure 4). The patient underwent right salpingo-oophorectomy and received two packed red blood cell transfusions. She recovered successfully, with a postoperative haemoglobin of 7.6 g/dL. Histopathology confirmed a well-differentiated adult granulosa cell tumour (GCT). The patient was advised to do a postoperative inhibin B and referred to a dedicated oncology centre for chemotherapy and follow-up.

Figure 1.

Axial T2 weighted images (A) and coronal T2WI (B) show a predominantly T2 heterogeneous pelvic mass lesion with internal T2 hyperintensities (white arrows). Free fluid is also noted in the abdomen (star). Axial T2WI (C) and coronal T2WI (D) show a twisted vascular pedicle in the right adnexa supplying the mass (red arrows).

Figure 2.

(A) Axial gradient recalled echo image shows areas of blooming within the mass (white arrow) suggesting haemorrhage and within the peritoneal fluid (star) indicating haemoperitoneum. (B) Axial T1 weighted images shows T1 hyperintense areas within the mass, indicating subacute haemorrhage (black arrow).

Figure 3.

(A) Sagittal T2 weighted images shows an unremarkable uterus and endometrium (thick white arrow) with few nabothian cysts in cervix (thin white arrow). (B) Axial T2WI shows incidentally detected horseshoe kidney (black arrow).

Figure 4.

Postoperative image of the ruptured haemorrhagic ovarian tumour.

GCTs are rare stromal cell neoplasms, accounting for 3%–5% of ovarian neoplasms.¹ They are categorised into juvenile and adult types, the latter affecting peri- and postmenopausal women, with a peak incidence around 50–55 years.² Symptoms vary due to mass effect or hyperoestrogenism. Rupture or torsion is uncommon, and existing literature infers the incidence to be <10% and <2%, respectively.^{3 4} The uniqueness of our case is its simultaneous presentation with both complications. Anti-Mullerian hormone and inhibin B are useful tumour markers with increased sensitivity and specificity, playing an important role in detecting both newly diagnosed and recurrent adult GCTs. While histopathology is necessary for a definitive diagnosis, imaging is crucial in assessing the extent of tumours. Sonography is invaluable in the initial assessment; however, MRI is superior as it offers excellent soft tissue resolution without radiation. MRI also helps characterise indeterminate ovarian masses, as adult GCTs can exhibit a myriad of imaging features ranging from solid lesions with haemorrhagic or fibrotic alterations to multilocular cysts or even entirely cystic mass lesions.⁵ Notably, GCTs typically show variable FDG avidity owing to their low-grade nature and are often associated with inaccurate diagnosis on PET-CT scans.⁶ Staging typically follows the FIGO criteria, with chemotherapy recommended for stages II to IV.

Currently, very few cases of adult GCT with both rupture and torsion have been reported,^{7 8} highlighting the rarity of this presentation. Notably, MRI findings described in this case have not been previously documented for similar cases. MRI is pivotal for tumour extent, vascular pedicle and nodal involvement. We thus emphasise its use as a problem-solving tool to evaluate adult GCTs presenting as acute abdomen, providing distinct details that aid clinicians in treatment planning.

Learning points.

• Ovarian tumours may present as acute abdomen either due to rupture or torsion. Both are clinical emergencies which have to be dealt with immediately. We advocate an increased clinical suspicion for torsion and rupture in ovarian tumours presenting with acute abdomen and ascites.

• MRI plays an important role in the accurate evaluation of ovarian tumours and their complications.

• Granulosa cell tumours with both torsion and rupture are extremely rare with only very few reported cases.

Ethics statements

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