A huge retroperitoneal ganglioneuroma in a middle-aged patient: Report of a diagnostically challenging case with review of the literature.

Ganglioneuromas (GNs) are benign, slow-growing tumors of neural crest cell origin. On rare occasions, adipose cells have been detected in these tumors. The present study reported a case of a huge retroperitoneal GN misdiagnosed and mismanaged as a liposarcoma. A 54-year-old male patient presented with gradually progressing dull back pain with abdominal discomfort for the past 6 months. The patient had abdominal distention and mild right abdominal tenderness. Ultrasound of the abdomen and pelvis revealed a large right-sided retroperitoneal mass. Contrast-enhanced computed tomography findings were consistent with sarcoma. Cytologic examination was suggestive of liposarcoma. A decision was made to start neoadjuvant radiochemotherapy, which proved ineffective. Complete surgical excision of the mass was performed via a midline laparotomy. Histopathology of the mass confirmed the diagnosis of GN. At two years post-operation, the patient developed a recurrence in the subhepatic area with the same diagnosis and the recurrent mass was surgically removed. Initially, the imaging findings were not sufficiently specific to establish the diagnosis. Rarely, cytologic techniques have detected adipose cells in these tumors, resulting in misdiagnosis. Hence, histopathology is the gold standard for definitive diagnosis. Preoperative diagnosis of GN is difficult due to the lack of specific clinical manifestations, radiological confusion with other tumors and the presence of adipocytes in rare cases, leading to misdiagnosis and mismanagement.