Isolated fallopian tube torsion (IFTT) associated with hydrosalpinx in an adolescent: a case report.

Introduction: Isolated fallopian tube torsion (IFTT) is a rare and often under-recognized cause of acute lower abdominal pain, particularly in adolescents. Clinical features are nonspecific and frequently mimic more common conditions, such as appendicitis or ovarian torsion, leading to delayed diagnosis and an increased risk of tubal necrosis. Association with hydrosalpinx in young patients without traditional risk factors is uncommon. Case presentation: A 15-year-old nulligravid girl with regular menses and no history of sexual activity or prior pelvic surgery presented with a 2-day history of severe, continuous lower abdominal pain, nausea, and vomiting. Examination revealed localized lower abdominal tenderness without peritoneal signs. Laboratory tests showed leukocytosis with neutrophilia; urinalysis was normal. Transabdominal ultrasonography was inconclusive due to body habitus. Contrast-enhanced computed tomography showed a right-sided cystic tubular adnexal structure consistent with hydrosalpinx, a central whirlpool configuration, a normal right ovary, and minimal free fluid, raising suspicion for IFTT. Urgent laparotomy confirmed isolated torsion of the right fallopian tube with necrosis; right salpingectomy was performed. The postoperative course was uneventful. Discussion: This case highlights the diagnostic challenge of IFTT. The coexistence of hydrosalpinx in an adolescent without prior infection or surgery underscores a possible role of tubal pathology in the pathogenesis of torsion. Conclusion: IFTT should be considered in adolescents with unilateral pelvic pain and normal-appearing ovaries to enable timely, fertility-conscious management.