Gastrointestinal stromal tumor of the appendix presenting as abdominal pain

• Published in: Nihon Rinsho Geka Gakkai Zasshi (Journal of Japan Surgical Association) Vol. 73; no. 5; pp. 1134 - 1139
• Main Authors: YAMAGUCHI, Masaki, BABA, Katsuyoshi, TAKAO, Takashi, HONMA, Kenichi, SHINGAMI, Kouji, UJI, Yoshitaka
• Format: Journal Article
• Language: Japanese
• Published: Japan Surgical Association 2012
• Subjects: abscess; appendix; GIST
• ISSN: 1345-2843; 1882-5133
• DOI: 10.3919/jjsa.73.1134

A 38-year-old female presented with right lower quadrant abdominal pains. The patient was evaluated using ultrasonography and computed tomography ; appendicitis with an abscess in the appendix proximal to the cecum was noted. The patient was given antibacterial drug therapy and underwent a laparoscopic appendectomy. During surgery, a tumor in the proximal portion of the appendix was found. The cut surface of the tumor was pale yellow with no hemorrhagic or necrotic foci. On histology, intricate spindle cells were seen. Immunostaining for KIT was positive. The mitotic activity was 2/50 high power fields (HPF). The tumor was diagnosed as a very low-grade appendiceal gastrointestinal stromal tumor (GIST). Only 9 cases of appendiceal GIST have been previously reported in the literature, and they account for approximately 0.1% of all cases of GIST. Thus, this patient is an extremely rare case.