Appendiceal schwannoma presenting as acute appendicitis

Abstract

Schwannomas are nerve sheath tumors that rarely occur in the gastrointestinal tract. In the gastrointestinal tract, schwannomas are mostly found in the stomach and small bowel. Herein, we describe a case of appendiceal schwannoma that caused appendix obstruction and developed acute appendicitis. An 83-year-old woman was admitted to the emergency department with 3 days' history of abdominal pain. She had tenderness and rebound tenderness in the lower right quadrant. Computed tomography revealed a 1.3 cm mass in the appendix orifice, with associated distal appendiceal dilatation and wall thickening. The patient underwent emergency surgery (laparoscopic partial cecectomy). Histopathological examination confirmed that the mass was a schwannoma and was associated with acute suppurative appendicitis. Our case is significant in that it adds to another rarely reported case of appendiceal schwannoma. Moreover, it is important to recognize the presence of an appendiceal tumor associated with acute appendicitis.

Keywords: Appendiceal schwannoma; Appendicitis; Case report; Computed tomography.

Fig. 1

Axial computed tomography scans. (A, B) A well-defined ovoid homogeneously enhancing mass measuring 1.3 cm is seen at the cecal tip. (C, D) Distal appendix is dilated, with wall thickening, and surrounding fat infiltration.

Fig. 2

Contrast-enhanced coronal and sagittal computed tomography scans. (A, B) The mass is located in submucosal layer, and has normal overlying mucosa (A, arrow heads).

Fig. 3

Histopathological findings. (A) Microscopic examination reveals proliferation of the spindle cells, which form the Verocay body (circle, hematoxylin and eosin stain, ×100). (B) Immunohistochemistry demonstrates strong and diffuse staining of the S-100 protein (×100).