Right Mesocolic Dermoid Cyst: A Case Report and Literature Review

Introduction: A dermoid cyst (DC), also known as a mature teratoma, can arise from either an acquired epithelial inclusion or be linked to congenital ectodermal implantation during embryogenesis. Abdominal localization of DC is rare. In this study, we report the case of a DC discovered incidentally in a young patient following imaging performed after a blunt thoracoabdominal trauma. Case Presentation: This is a 36-year-old asthmatic patient in whom a right mesocolic cystic mass was discovered incidentally. The mass was the cause of right lumbago, which necessitated surgical removal by laparotomy due to its large size. The patient also had gallbladder lithiasis, which was removed during the same procedure. Conclusions: Abdominal DC is a rare form, especially when compared with gonadal forms, which are more common in women (such as teratomas of the ovary). Symptoms vary depending on the viscera compressed, and they may cause pain or provoke acute surgical conditions, such as volvulus or peritonitis due to intra-abdominal rupture of the cystic contents. Chemical peritonitis caused by rupture is difficult to treat and may require repeated laparotomies. Imaging strongly suggests the diagnosis, typically showing a well-defined liquid formation with calcifications. The main differential diagnoses include cystic lymphangioma and digestive duplicity. The treatment is surgical, and complete resection is essential to prevent complications and recurrence. Laparoscopic excision may be considered in selective patients with experienced surgical teams. Intraperitoneal localization of DC is rare, and its clinical presentation is highly variable. Diagnosis is suspected based on imaging and can only be confirmed histologically after surgery. All abdominal DCs should be surgically removed due to the risk of rupture. While malignant degeneration is possible, it remains exceptional.