Management of Retroperitoneal Schwannoma: Case Reports and Review of the Literature

Abstract

Schwannoma is a rare slow-growing neurogenic tumor of the nerve sheath origin. They are commonly seen in middle-aged with a female to male ratio of 1:1.2. Here we present three cases of retroperitoneal schwannoma in our urology department. In two cases, we decided surgery management and in one case, we used watchful waiting. After a 3-year follow-up, case 1 was asymptomatic without changes in the lesion. Keywords: Schwannoma; Retroperitoneal malignance; Neurogenic tumor IntroductionSchwannoma is a slow-growing neurogenic tumor of the nerve sheath origin. They are commonly seen in middle-aged with a female to male ratio of 1:1.2. Visceral schwannomas are infrequent. Computerized tomography (CT) images present areas of cystic degeneration, calcification or hemorrhage. Extension of the mass along the nerve may indicate the neural origin of the mass. It is important to exclude a malignant retroperitoneal tumor to choose the correct treatment.Here we present three cases of retroperitoneal schwannoma in our urology department. Case Reports Case 1A 54-year-old female smoker presented in our department with back pain on the right. Abdominal ultrasound and CT with contrast revealed a 4.2 × 3.2 cm mass located in the retrocaval area and medial to the right kidney (Fig. 1). The findings of the images were compatible with pheochromocytoma or paraganglioma. Biochemical workup included plasma and urine catecholamine. All studies were normal. The imagingguided biopsy was done. Microscopic findings showed a mass composed of fusiform cells with abundant collagen and spaces with macrophages. No mitoses were observed. Immunohistochemistry showed that the tumor cells were positive for S-100, BCL2, CD56, CD99 and negative for CD34 and muscle specific actin and desmin. The Ki67 activity was 1%. These findings were consistent with benign schwannoma.Because it was a benign case with small mass and the patient was asymptomatic, we decided watchful waiting with radiological periodic controls. Case 2A 56-year-old woman smoker was dispatched to the hematology department with thrombocytopenia after a routine health

Benign adrenal and suprarenal retroperitoneal schwannomas can mimic aggressive adrenal malignancies: case report and review of the literature

“…demonstrating positivity (8). Hirose et al identified GFAP positivity in 92% of their RP cellular/fascicular type schwannomas, which would be consistent with GFAP positivity seen in our cellular type schwannoma.…”

Retroperitoneal Schwannoma: Two Rare Case Reports

“…CT scan with contrast shows classically a well-defined tumor with slightly low density compared with soft tissue due to the high presence of myelin and fat [ 8 ]. MRI is superior to CT in defining the margins and identifying the nerve origin [ 9 ]. Schwannomas are commonly hypointense on T1 and hyperintense on T2-weighted MR images [ 8 ].…”

“…The target sign (a hypointense center with a hyperintense periphery) and fascicular sign (bundles) are two well-known characteristic features of neurogenic tumors on MRI; however, they are not seen frequently in RSs [ 10 ]. Malignant schwannomas have irregular contours, exhibit mixed intensity on both T1- and T2-weighted images, and tend to invade other structures; however, they are extremely rare in patients without a history of neurofibromatosis [ 9 , 11 ].…”