Abdominal mouse: Floating intra-abdominal cystic lymphatic malformation - An exceedingly rare case report.

Introduction and importance: Lymphangiomas are rare benign lymphatic malformations, typically affecting the head, neck, or axillary regions, with abdominal cystic lymphatic malformations (CLM) being particularly uncommon in adults. Abdominal CLM account for less than 5 % of all lymphangiomas and 7 % of all abdominal cystic lesions in adults with a prevalence of approximately 1 in 250,000. These lesions are commonly found by accident during imaging investigations and are asymptomatic. Being free of any attachment, floating in the peritoneal cavity make it unique in its presentation.

Case presentation: We report a case of 25-year-old female who complaining of right upper abdominal pain. Initial laboratory and imaging studies by abdominal computed tomography (CT) scan showed multiple complex cysts with undetermined origin. Exploration laparoscopy was performed, revealing over 50 variable-sized cysts, some of them were floating freely within the abdominal cavity. Complete resection of all cysts was performed. Postoperative recovery was uneventful, and histopathological examination confirmed the diagnosis of cystic lymphangiomas.

Clinical discussion: This case demonstrates the unusual presentation of multiple, floating, and variably sized intra-abdominal cystic lymphangiomas, a rare finding that presents significant diagnostic and management challenges. The absence of attachment to common intra-abdominal structures, such as the mesentery or omentum, further complicates the clinical picture.

Conclusion: Abdominal CLM must be considered as possible diagnosis especially if the cysts are multiple and complex. Freely floating abdominal CLM may cause the symptoms of a moving lump described by the patient, which must be taken in consideration.