Mesenteric cystic lymphatic malformation: a rare case report and review of the literature.

Background: Mesenteric cystic lymphatic malformation (LM) is a rare congenital benign malformation in adults, and its location in the mesentery of the sigmoid colon is even rarer. Case Description: We describe a rare case of LM of the mesentery in a 49-year-old woman. The patient was inadvertently identified during a physical examination 1 month earlier. Transvaginal ultrasound and magnetic resonance imaging (MRI) revealed the presence of an intrapelvic mass posterior to the uterus and right anterior to the sigmoid colon. According to the results of the ultrasound, the mass showed hypoechoic solid features with a blood flow signal, and MRI showed that the internal enhancement of the mass was uneven. According to its imaging characteristics, it was preliminarily speculated as a stromal tumor. The patient underwent laparoscopic fenestration and drainage of a sigmoid mesocolic cyst. The patient underwent laparoscopic fenestration and drainage of the sigmoid mesocolic cyst. The pathological diagnosis was cystic lymphangioma of the sigmoid mesangium. After the operation, the patient recovered well without any complications. No recurrence was observed during the 3-month follow-up. Conclusions: LM is a challenging and rare disease, and its diagnosis is difficult. However, the combination of imaging examination and endoscopic ultrasound (EUS) technology can significantly improve the accurate diagnosis rate of the disease. Complete resection is the best choice for definite diagnosis and prevention of recurrence. It has been proved that laparoscopic surgery is a safe and feasible method for the treatment of this disease.