Giant serous cystadenoma in an adolescent: A case report.

Ovarian tumours occur at an incidence rate of 2.6 cases per 100,000 children, and their frequency escalates proportionally with age. These tumours typically have an organic origin and are seldom functional. The frequent presence of pain primarily characterizes the clinical manifestation of ovarian cysts. The complexity inherent in analyzing this pain can complicate diagnosis, necessitating a thorough evaluation that could potentially require resorting to a pelvic ultrasound to confirm the diagnosis and determine the optimal management. Additional imaging techniques and tumour marker assays aid in specifying the nature of this mass, where surgery remains the sole therapeutic option. The histopathological analysis further confirms the precise nature of the mass or cyst to establish a prognosis and guide the management strategies and progression follow-up. Our case is for a girl aged 15 years old without notable medical history, presenting at admission with a 6-month history of a gradually enlarging abdominal mass associated with abdominal pain and tumour markers (BHCG was negative). In addition, LDH, CA125, Inhibin, CEA and CA19.9 were negative. Radiologically, the ultrasound revealed a huge cystic abdominopelvic mass occupying the entirety of the abdomen and pelvis with posterior compression of the intestines without visualization of the left ovary; the right ovary appeared normal. MRI confirmed the presence of a voluminous intraperitoneal abdominopelvic cystic formation measuring 31 × 20 × 8 cm. The patient underwent laparoscopic surgery, revealing a large cystic mass with septations filling the abdomen and pelvis and displacing the gastrointestinal tract. After draining 6 L of clear fluid, the entire cyst was removed while preserving some left ovarian tissue, with the right ovary appearing normal. The follow-up is still ongoing, with the last consultation being 8 months post-operative.