Abstract
Background: Isolated fallopian tube torsion (IFTT) is an uncommon cause of pelvic pain and is exceptionally rare after menopause, often leading to delayed diagnosis [1,2]. Cross-sectional imaging plays a crucial role when ultrasound findings are inconclusive [3,4]. We report a case with comprehensive imaging and histopathological correlation.

Case Presentation: A 61-year-old postmenopausal woman (G1P0 with a history of spontaneous miscarriage) presented with intermittent hypogastric pain for 10 days with acute worsening five days before admission. She had no gastrointestinal or urinary symptoms, and her vital signs were stable. Physical examination revealed a tender, firm mass in the hypogastric and peri-umbilical region; bimanual pelvic examination was limited due to pain but suggested a right adnexal mass. Ultrasonography demonstrated a supra-uterine cystic formation with incomplete internal septa; the ipsilateral ovary was not visualized separately. Contrast-enhanced CT showed a midline tubular cystic structure, coiled and deviated to the right, associated with uterine verticalization and rightward displacement, surrounding fat stranding, and small-volume intraperitoneal fluid. Pelvic MRI confirmed a coiled tubular cystic lesion attached to the uterine fundus with a visible twist (whirlpool sign) and demonstrated T1/T2 hyperintense contents, thickened walls with frond-like projections, and adjacent inflammatory changes [4,5]. The ipsilateral ovary appeared normal for age. A diagnosis of isolated fallopian tube torsion was proposed. Laparotomy confirmed a twisted right tubulated cystic formation with a normal ipsilateral ovary. Salpingo-oophorectomy was performed because, in a postmenopausal patient with concern for underlying pathology, complete excision was deemed the safest approach. Histopathological examination found a cystic structure with a hemorrhagic and inflamed cystic adnexal structure without evidence of malignancy, consistent with torsion-related ischemic change. No malignancy was found. The ipsilateral ovary was present and normal, confirming the diagnosis of isolated fallopian tube torsion.

Conclusion: Identification of a twisted extra-ovarian tubular cystic structure with a normal ipsilateral ovary on CT and MRI is highly suggestive of IFTT [4,6]. Awareness of this imaging pattern, particularly in postmenopausal patients, allows for timely diagnosis and surgical management, thereby preventing complications.

Key words: Postmenopausal pelvic pain; isolated fallopian tube torsion; computed tomography; magnetic resonance imaging