Robotic Resection of a Retroperitoneal Ganglioneuroma

GN belong to the group of neuroblastic tumors, which originate from the neural crest and are composed of mature ganglion cells and Schwann cells. Most are asymptomatic and found accidentally. The treatment of retroperitoneal mass is complete surgical excision. In the literature, the number of retroperitoneal masses reported is quite limited. Careful dissection and preservation of these structures is capital, especially in case of benign retroperitoneal masses. We report a case of robotic excision of a retroperitoneal ganglioneuroma.

Figure 1:MRI.

A 32-year-old male patient without comorbidities presented with sporadic abdominal pain. He had not undergone abdominal ultrasound due to SARS-COV-2 pandemic. In November he felt symptoms compatible with COVID-19, latter on confirmed with a PCR test. Patient underwent chest tomography and was found incidentally a retroperitoneal mass, left paraaortic, at the level of the renal hilum on this side, with approximately 3.4cm, appearing to contain internal fatty areas, partially included here. It was necessary to proceed with diagnostic investigation, preferably through MRI of the upper abdomen for further elucidation. In view of the findings, he performed an abdominal MRI scan (Figure 1) that identified: expansive heterogeneous and lobulated retroperitoneum para-aortic lesion on the left, just below the renal vessels on this side, measuring 5x5x3.5x3.2cm. It presented heterogeneous hypersignal in T2-weighted sequences, discreet and late enhancement and spots of micro and macroscopic fatty content. There was little insinuation of the lesion in the left anterior pre-vertebral space (level L1 / L2), without compromising the intervertebral foramen or adjacent organs. The possibility of injury to the mesenchymal lineage (mainly a liposarcoma) should be considered, admitting differential with injury of neural or paraganglionic origin. Computed tomography-guided lesion biopsy of the lesion suggested neuroblastic neoplasia with ganglioneuroma characteristics [1,2]. Due to the findings, the patient underwent retroperitoneal tumor resection and robotic retroperitoneal lymphadenectomy with the Da Vinci XI robot. Patient was positioned in a left flank position and five ports were introduced transperitoneally. Intraoperative ultrasound was performed for the precise identification of the lesion and cautious tumor dissection and resection was performed, which had minimal contact with the left renal vein (Figure 2). The procedure took about 150 minutes, with an estimated loss of 80mL of blood and the patient was discharged on the 3rd postoperative day. The anatomopathological examination revealed a maturing ganglioneuroma a peripheral neural sheath neoplasm consisting mainly of a schwannomatous component and mature and in-between maturation ganglion cells. Classification INPC (International Neuroblastoma Pathology Classification) - favorable histology [3,4].

Figure 2:Intra-operative image of the retroperitoneal mass.