A comprehensive radiologic review of abdominal and pelvic torsions

Torsed retroperitoneal leiomyomas: A case report and review of literature

BACKGROUND

Retroperitoneal leiomyomas (RLs) are rare benign tumours that can occur in the pelvic and/or abdominal parietal retroperitoneum. Once torsion occurs, it causes acute abdominal pain and can even lead to serious consequences such as gangrene, peritonitis, haemoperitoneum and shock if not identified and treated promptly. Therefore, a better understanding of the characteristics of RL torsion is needed. Here, we present a case of acute pedicle torsion of an RL in the posterior peritoneum followed by a literature review.

CASE SUMMARY

Herein, we report the case of a 42-year-old woman with RL torsion. The patient visited our hospital complaining of lower abdominal pain for 6 d. Pelvic examination revealed a tender mass superior to the uterus. Pelvic magnetic resonance imaging (MRI) revealed an anterior uterine mass, multiple uterine fibroids and slight pelvic effusion. MRI suggested the possibility of a subserosal myoma of the anterior uterine wall with degeneration. Intraoperative exploration revealed a 10 cm pedunculated mass arising from the posterior peritoneum, with the pedicle torsed two times. Pathological examination confirmed a torsed RL.

CONCLUSION

In the case of a pelvic mass complicated with acute abdomen, the possibility of torsion should be considered.

Imaging Features of Uncommon Entities That Manifest with Torsion

Torsion is the twisting of an object along the axis, and various structures (organs and tumors) in the body can twist. Torsion causes initial lymphatic and venous outflow obstruction, leading to congestive edema, enlargement, venous hemorrhagic infarction, and surrounding edema. It can also cause subsequent arterial obstruction depending on the degree of torsion, leading to ischemia, infarction, necrosis, gangrene, and surrounding inflammation. Therefore, in several cases of torsion, immediate surgical intervention is required to improve blood flow and prevent serious complications. Clinical manifestations of torsion are often nonspecific and can affect individuals of varying ages and sex. Imaging plays an important role in the early diagnosis and management of torsion. Multiple imaging modalities, including US, radiography, CT, and MRI, are used to evaluate torsion, and each modality has its specific characteristics. The imaging findings reflect the pathophysiologic mechanism: a twisted pedicle (whirlpool sign), enlargement of the torsed structures, reduced blood flow, internal heterogeneity, and surrounding reactive changes. The whirlpool sign is a definitive characteristic of torsion. In some cases, despite poor internal enhancement, capsular enhancement is observed on contrast-enhanced CT and MR images and is considered to be associated with preserved capsular arterial flow or capsular neovascularization due to inflammation. Radiologists should be familiar with the pathophysiologic mechanisms, clinical characteristics, and imaging characteristics of torsion in various structures in the body. Since other articles about common organ torsions already exist, the authors of this article focus on the uncommon entities that manifest with torsion. ©RSNA, 2024.

Abdominal and pelvic splenosis: atypical findings, pitfalls, and mimics

Splenosis is an acquired form of ectopic splenic tissue that typically arises after trauma or splenectomy. It is often an incidental image finding in an otherwise asymptomatic patient, but the spectrum of symptoms varies based on the site of implantation. Radiologists should be familiar with the imaging features of splenosis to avoid mistaking it for malignancy. Splenosis has identical imaging features to that of the native spleen on US, CT, MRI, and nuclear medicine examinations. Therefore, when the radiologic findings support the diagnosis of splenosis, the patient can be spared invasive procedures for tissue sampling.