Adenomyosis-associated uterine rupture and pulmonary endometriosis mimicking advanced-stage uterine malignancy in an adolescent female: A case report.

Background: Uterine adenomyosis and pulmonary endometriosis are exceptionally rare in adolescents and can pose significant diagnostic challenges due to their nonspecific clinical presentation and imaging features, which may mimic malignancy. Here, we describe a case of adenomyosis-associated uterine rupture (secondary to hemorrhagic necrosis) and concurrent pulmonary endometriosis in a 16-year-old girl initially suspected of having advanced uterine cancer.

Case summary: A 16-year-old girl presented with acute abdominal pain and oliguria. Imaging studies revealed a 15-cm ruptured uterine mass accompanied by hemoperitoneum and multiple pulmonary nodules suggestive of metastatic disease. Laboratory tests demonstrated severe anemia and markedly elevated tumor markers [cancer antigen (CA)-125: 1063 U/mL; CA-19-9: 1347 U/mL]. Emergency laparotomy revealed adenomyosis-associated uterine rupture secondary to hemorrhagic necrosis, with no macroscopic abnormalities in other organs. A total abdominal hysterectomy was performed. Histopathological analysis confirmed uterine adenomyosis with hemorrhagic necrosis. Subsequent thoracoscopic wedge resections of the pulmonary lesions demonstrated histologically confirmed endometriosis. The patient has remained disease-free under treatment with oral dienogest.

Conclusion: This case of an adolescent patient highlights how benign gynecological conditions can mimic malignancy, necessitating broad differential diagnoses despite alarming presentations.