Retroperitoneal space-occupying lesion with displacement of the inferior vena cava

Abstract

Introduction: The differential diagnosis and therapy of retroperitoneal masses suspicious for soft tissue tumors remains difficult and needs individual decisions as to the best management of patients. We report an unusual case of retroperitoneal schwannoma (RS).

Presentation of case: We report on a 57-year-old female patient with a retroperitoneal space-occupying lesion with displacement, but no infiltration of surrounding vessels, especially the inferior vena cava. As presence of malignancy could not be completely excluded by imaging and biopsy, we performed an open resection of the tumor with plastic reconstruction of the right renal vein. Curative resection of the tumor could be achieved and benign RS verified.

Discussion: Preoperative work-up, including a broad spectrum of differential diagnoses, and consecutive appropriate surgical resection are challenging. Characteristic features of the pre-therapeutic diagnostics of retroperitoneal schwannomas are discussed and differential diagnostic considerations as well as surgical therapeutic options are outlined.

Conclusion: Deeper understanding of retroperitoneal schwannomas gained from preoperative radiologic diagnostics may serve to underline the need for targeted biopsy. This and its histopathological examination necessitate expert interventional radiologists and pathologists. Thus, even the pre-therapeutic diagnostic management should be performed in a specialized center. If doubts remain regarding the entity of the retroperitoneal lesion and findings are still controversial after thorough assessment, surgical oncologic resection represents the therapy of choice, if the surgical risk is adequate.

Keywords: Imaging modalities; Preoperative biopsy; Retroperitoneal schwannoma; Retroperitoneal space-occupying soft-tissue tumor; Surgical strategy.

Fig. 1

The CT examination (after intravenous contrast administration, transverse section) shows a large, retroperitoneal space-occupying lesion right para-aortal, causing marked ventral displacement of the inferior vena cava, the right renal vein and the adjacent duodenum. Partially visible calcification left ventral within the additionally inhomogeneous lesion as the image morphologic correlate of histopathologically partially identifiable marked regressive changes.

Fig. 2

[¹⁸F]FDG-PET/CT confirmed the presence of a lateral space-occupying lesion para-aortal right at the level of the renal hilus with a malignoma-typical increase in metabolic activity in the marginal areas.

Fig. 3

A) Intraoperative situs: We performed an open resection of the tumor with plastic reconstruction of the right renal vein (blue vessel loop and Satinski clamp: right renal vein). B) Macroscopy of the en bloc-specimen revealed a solid, greyish, spherical tumor with a soft capsule and a heterogeneous center. The surrounding “pseudocapsule” was completely removed. Curative (R0) resection was confirmed.

Fig. 4

A) HE – 25x: Overview image of the resected tissue with richly vascular areas and myxoid-regressive alterations at the image center. B) S100 – 200x: Immunohistochemistry for S100 with positive tumor cells and negative vessels obtained by punch-assisted biopsy.