Giant retroperitoneal ancient schwannoma: An unusual schwannoma type in the rarest localization

Abstract

Schwannomas are tumors originating from Schwann cells in the nerve sheath. Although they can appear on many parts of thebody, they occur most frequently in the head and neck. Furthermore, they are very rarely seen in the retroperitoneal region. Ancientschwannoma is a sub-type of schwannomas that is quite rare. In this study, the case of a retroperitoneal ancient schwannoma,which showed cystic degeneration and reached gigantic sizes, is presented. A forty-nine-year-old female patient was admittedto our center with complaints of growing abdominal distention and stiffness for 7 years. In the physical examination, a non-mobileand stiff mass that was approximately 30 cm along its longest axis and extended from the subcostal area to the inguinal regionwas detected on the right side of the abdomen. A solid retroperitoneal mass containing encapsulated and cystic components wasconfirmed in the oral and intravenous contrasted abdominopelvic tomography. The size of the mass was 28×20×12 cm, and atotal excision of the mass was planned. The mass was excised together with the capsule. In the pathological examination, ancientschwannoma, which showed widespread multifocal cystic degeneration with benign characteristic, was found. In the immunohistochemicalstaining, S100 was found to be positive. The patient was discharged on the 5th postoperative day. Schwannomasare slowly progressive benign tumors that can reach a large size without any symptoms and rarely settle in the retroperitonealregion. Ancient schwannomas are also a rarely seen sub-type of schwannomas. In this study, the case of a retroperitoneal ancientschwannoma, which showed cystic degeneration and reached gigantic sizes, is presented.