Schwannoma of the abdominal wall: updated literature review

Abstract

Summary Background Schwannoma is a benign tumor arising from Schwann cells of the peripheral nerves. It is often asymptomatic and can develop in the retroperitoneum, mediastinum, head and neck region, and upper and lower extremities. Schwannoma of the abdominal wall is extremely rare, but differential diagnosis with malignant neoplasms is important to reduce the risk of undertreatment. Methods A narrative review of abdominal wall schwannoma was performed using PubMed, EMBASE, and Web of Science database and the search terms “schwannoma”, “neurinoma”, “neurilemmoma”, “soft tissue tumors”, “neurogenic tumor”, “rectus abdominis mass”, “abdominal wall”. In addition, the hospital charts were reviewed to report the personal experience. Results Only 9 single case-reports of benign schwannoma of the abdominal wall were found in the English medical literature over the past decade. None of the patients received preoperative biopsy and all were resected with clear margins. In addition to the literature review, we report the case of a 58-year-old man referred for a palpable mass in the left upper abdominal quadrant. Ultrasonography and magnetic resonance imaging revealed a solid and well-encapsulated mass inside the left rectus abdominis muscle. A core biopsy of the lesion provided the diagnosis of cellular schwannoma and this was confirmed by histopathologic examination of the surgical specimen. Conclusions Benign schwannoma of the abdominal wall is extremely rare. Percutaneous core needle biopsy is important for the differential diagnosis with more common and biologically more aggressive malignancies, such as desmoid tumors and sarcomas, and may be relevant for planning the most appropriate management.