CASE 18341 Published on 13.10.2023

Cystic degeneration of the adnexa: A rare feature of longstanding torsion


Genital (female) imaging

Case Type

Clinical Cases


Catarina Janicas 1, Sância Ramos 2, Carla Saraiva 1

1 Department of Radiology, Centro Hospitalar de Lisboa Ocidental, Lisbon, Portugal

2 Department of Pathology, Centro Hospitalar de Lisboa Ocidental, Lisbon, Portugal


46 years, female

Area of Interest Emergency, Genital / Reproductive system female ; Imaging Technique CT, Ultrasound, Ultrasound-Colour Doppler
Clinical History

A 46-year-old woman was admitted for a 24-hour history of nausea and severe refractory pain in the hypogastrium and right iliac fossa. The patient reported previous episodes of premenstrual pelvic pain, although less intense and responsive to analgesics. The laboratory tests were unremarkable, except for moderate leukocytosis with neutrophilia.

Imaging Findings

Transabdominal ultrasound revealed a complex mass lying in front of the uterus, showing homogeneously scattered cysts and no codification on colour Doppler (Figure 1). Since the right adnexa was not identified, these findings were considered highly suspicious of adnexal torsion. Contrast-enhanced dual-energy CT confirmed the right adnexal origin of the mass, which revealed scarce enhancement and areas of increased density (Figure 2). The fallopian tube was thickened and twisted around the hypodense ovarian vascular pedicle, all in keeping with adnexal torsion. However, whether the mass corresponded solely to the enlarged ovary or an adnexal lesion remained unclear.

Pathological examination of the right salpingo-oophorectomy specimen confirmed the absence of underlying lesions. The mass consisted solely of ovarian parenchyma with extensive oedema and venous congestion, leading to the development of pseudocysts (Figures 3 and 4).

The patient recovered well and was soon discharged.


Adnexal torsion occurs when the ovary and fallopian tube twist around the infundibulopelvic and ovarian ligaments, leading to twisting and compression of the ovarian vessels [1–3]. An underlying lesion is the leading point for torsion in 50-90% [3], the vast majority being benign lesions such as simple cysts and mature teratomas [1]. Patients classically present with severe acute pelvic pain, often associated with nausea and vomiting [1–3]. Laboratory tests are nonspecific, revealing moderate leukocytosis and increased inflammatory markers [2].

The chief imaging finding of adnexal torsion is ovarian enlargement, defined by a volume greater than 20 cm3 in premenopausal and 10 cm3 in postmenopausal women [3]. The enlarged ovary is displaced into the midline and deviates the uterus towards the affected side, contrary to the usual effect of adnexal lesions. Ultrasound also reveals hypoechogenicity of the central stroma and peripheral displacement of follicles, assuming a “string of pearls” configuration. The whirlpool sign of a twisted vascular pedicle is pathognomic, although often difficult to demonstrate, and may or may not show flow codification. In addition, CT and MR may reveal hemorrhagic foci, as well as hypo or non-enhancement of the torsed adnexa, once more depending on the degree of vascular obstruction [1,3].

In exceedingly rare cases, extensive venous congestion and stromal oedema may lead to the development of pseudocysts. They may be distinguished from follicles by their homogenous distribution within the ovary, including in the central afollicular stroma. However, only the pathologic examination can safely exclude an underlying complex lesion and confirm the oedematous nature of the cysts; in opposition to true cysts, pseudocysts are not lined by epithelium and, therefore, do not stain for CK AE1/AE3 [4].

If the ovary continues to appear nonviable after simple detorsion or if a suspicious lesion is identified, salpingo-oophorectomy is required. Otherwise, ovary preservation should always be attempted in fertile patients, since the primary concern of adnexal torsion relates to loss of ovarian function and subfertility [1,2].

In conclusion, prompt diagnosis of adnexal torsion is paramount, given that ischemia will progress to nonreversible necrosis with loss of ovarian function. Because an underlying lesion will impact surgical management, its presence and risk of malignancy must be carefully assessed. Cystic degeneration due to longstanding torsion is a rare form of presentation, which one must recognize as a potential mimicker.

All patient data have been completely anonymized throughout the entire manuscript and related files.

Differential Diagnosis List
Adnexal torsion with underlying lesion
Longstanding adnexal torsion with cystic degeneration
Massive ovarian oedema
Torsion of pedunculated leiomyoma
Degeneration of pedunculated leiomyoma
Final Diagnosis
Longstanding adnexal torsion with cystic degeneration
Case information
DOI: 10.35100/eurorad/case.18341
ISSN: 1563-4086