Giant retroperitoneal ancient schwannoma: Is preoperative biopsy always mandatory?

Abstract

Introduction: Schwannoma is the term given to tumours arising from Schwann cells of any nerve sheath. It may arise in the retroperitoneum, where it can attain enormous sizes and cause considerable diagnostic and therapeutic difficulties. A variety of incapacitating symptoms may arise, depending on its size alone and the related contagious organs.

Presentation of case: A 71-year-old female, who was incapacitated by a giant abdominal mass, associated with weight loss, immobility, general weakness and constipation. Radiologically, the presence of a huge pelviabdominal tumour was confirmed. A preoperative tissue diagnosis was entertained but omitted, and we resorted to direct surgical excision instead. During surgery, significant bleeding from the surrounding lumbar vessels was encountered, but it was controlled and the tumour was excised intact. Histopathologically, it showed the histologic features of ancient schwannoma.

Discussion: In the patient presented here, who was rendered immobile by the tumour, total excision or at least debulking seemed appropriate, regardless of any biopsy result.

Conclusion: The diagnosis of retroperitoneal schwannoma and its variant "ancient schwannoma" should be considered when a huge pelviabdominal tumour is encountered. Although CT guided biopsy may be helpful in reaching a preoperative diagnosis, this might not change the decision for the need of total tumour excision or at least debulking, in the presence of incapacitating symptoms. With large tumours, the possibility of perioperative exanginating haemorrhage should be remembered and the necessary precautions activated.

Keywords: Giant; Retroperitoneum; Schwannoma.

Fig. 1

CT scan showing heterogenous mass with cystic spaces and a well developed capsule.

Fig. 2

Intraoperative view of the swelling with the overlying dilated vessels.

Fig. 3

The intact swelling measuring 29 cm × 30 cm × 13 cm.

Fig. 4

A: Microphotograph showing Antoni A region with pallisade arrangement of cells (H&E ×100). B: On immunohistochemistry, the tumour tested positive for S-100 protein.

Fig. 5

GIST radiologic appearance is not dissimilar from that of schwannoma. Compare to Fig. 1. (First authors photo archive).