Schwannoma of the Appendix Orifice

Abstract

Schwannomas are rare mesenchymal tumors. They are usually diagnosed incidentally during endoscopic or diagnostic imaging for another reason. Malignant transformation is rare. In this case report, we present an incidental schwannoma protruding through the appendiceal orifice diagnosed during endoscopy. A healthy 56-year-old female underwent a surveillance colonoscopy for family history of colorectal cancer. A prominent and edematous appendiceal orifice was noted, and the area was aggressively biopsied. Histopathological assessment revealed a benign schwannoma. Computerized topography was unremarkable. Subsequently, the patient underwent a right hemicolectomy. Patient is scheduled to undergo routine surveillance in three years. Grossly, schwannomas are white, encapsulated, and well-circumscribed lesions that stain strongly positive for S100, GFAP, and CD57. Histologically, schwannomas demonstrate spindle cell proliferation. Several imaging modalities have been utilized in the diagnosis and management of mesenchymal neoplasms. Despite the benign nature of the diagnosis, complete surgical resection with clear margins remains the gold standard management strategy. Our case highlights the presence of a relatively uncommon tumor in an unusual anatomical location.

Figure 1

Coronal and cross-sectional views of computerized topography imaging demonstrating the appendiceal lesion.

Figure 2

(a) Spindle cell lesion in appendix wall predominantly in muscularis propria. (b) Associated benign lymphoid reaction-typical of gastrointestinal GI schwannoma. (c) S100 positivity in the lesion. (d) Bundles of bland spindle cells (high power). (e) Bundles of bland spindle cells (low power).