Unclear retroperitoneal tumors, an interdisciplinary challenge - A case report and review of the literature

Abstract

Introduction and importance: Unclear retroperitoneal tumors impose major challenges for clinicians. Tumors can originate primarily from retroperitoneal tissue or secondarily invade into the retroperitoneum. While benign lesions also occur, malignant tumors are far more common. Clinical presentation depends on replacement or invasion of other organs and is therefore highly variable. The heterogeneous tumor composition makes a definitive preoperative diagnosis difficult. Surgical resection is the gold standard for treatment but often proves challenging due to frequent involvement of large retroperitoneal vessels.

Case presentation: We present the case of a 70-year old woman diagnosed with a large, unclear retroperitoneal tumor. Initial clinical symptoms were increasing dyspnea and dysphagia in our clinic. Gastroenterologic and cardiologic workup was unremarkable. Computed Tomography (CT) revealed a large retroperitoneal mass in the right upper abdomen with severe displacement of the inferior vena cava and renal veins. The patient was scheduled for primary tumor resection. The procedure was challenging due to the vessel involvement and large blood pressure alterations during tumor mobilization. The post-op pathologic workup then revealed the rare finding of a completely resected paraganglioma. The post-surgical course was uneventful. One year after diagnosis, the patient is relapse-free.

Clinical discussion: Among retroperitoneal tumors, paragangliomas and pheochromocytomas are rare tumor entities. Asymptomatic, sporadic disease is hard to identify preoperatively and can cause unexpected complications in the OR. An experienced team is crucial in achieving best short- and long-term outcomes.

Conclusion: This case impressively shows the challenges of retroperitoneal tumors and the importance of interdisciplinary work in these cases.

Keywords: Case report; PPGL; Paraganglioma; Pheochromocytoma; Retroperitoneal tumor; Surgery.

Fig. 1

Pre-operative CT-scan. Native (A) and contrast-enhanced scans (B–D) in transversal (A–C) and coronar (D) sections. Asterix marks the predominantly cystic tumor, the white arrow marks the severely displaced IVC.

Fig. 2

Surgical tumor resection. A: Situs after explorative laparotomy reveals a large tumor in the lesser sac with displacement of liver, stomach and duodenum, hepatoduodenal ligament, and IVC (*). B: Situs after tumor resection with the IVC repositioned in its original position. IVC (1) and renal veins (2, 3) are secured with vessel loops. C: Tumor after resection, contact with IVC is marked with white dashed line.

Fig. 3

Pathological workup. Hematoxylin-eosin staining (A) and immunohistochemical staining (B–D) of the excised extra-adrenal sympathetic paraganglioma (magnification 400×). Polygonal medium sized and larger pleomorphic chief cells arrange in an organoid pattern (A). Chief cells stain for the neuroendocrine marker chromogranin-A (B). Sustentacular cells surrounding the chief cells stain for S100 protein (C). Tumor cells show a low proliferative activity in the Ki-67 staining (D).