Abstract
A 48-year-old woman was admitted to our hospital complaining of abdominal pain. Acute appendicitis was suspected from the physical examination findings, and abdominal CT and USG showed a swollen appendix with a tumor in the proximal portion of the organ. We made the diagnosis of appendiceal neoplasm with acute appendicitis, and scheduled radical operation after initial conservative treatment to control the symptoms. Colonoscopy showed a submucosal tumor of the vermiform appendix. Histological examination of a biopsy specimen revealed only mucosal inflammatory changes, however, an appendiceal carcinoma could not be ruled out. We performed laparoscopic-assisted ileocecal resection with lymph node dissection. The appendiceal tumor in the resected specimen was 2.0 cm in diameter, and histopathology revealed the tumor to be composed of spindle-shaped cells. Immunohistochemistry showed positive staining for S-100 protein, consistent with the diagnosis of appendiceal schwannoma. In most cases, appendiceal neoplasms are found accidentally and tend to be confused with acute appendicitis. Appendiceal schwannoma is rare and preoperative confirmation of the diagnosis is difficult. In cases where surgery is scheduled, it is often difficult to decide the resection area. Therefore, it is desirable to conduct further examination after the symptoms of acute appendicitis improve, in order to determine the appropriate surgical procedure.
