Acute appendicitis with a neuroendocrine tumor G1 (carcinoid): pitfalls of conservative treatment.
A man in his early thirties presented to our clinic with right lower abdominal pain. Computed tomography (CT) and ultrasonography (US) revealed a swollen appendix and an appendicolith. Abscess formation was not observed but ongoing appendiceal rupture was not ruled out. Three months after successful conservative therapy, the lumen of the apical portion was kept dilated and laparoscopic interval appendectomy was performed. No tumorous findings were observed macroscopically. However, histology revealed many tiny nests infiltrating the submucosa, muscular layer, and subserosa at the root of the appendix. An appendiceal neuroendocrine tumor G1 (NET G1; carcinoid) was diagnosed immunohistologically. Neither CT nor US visualized the tumor because of its non-tumor-forming but infiltrative growth. In conclusion, after successful conservative treatment, interval appendectomy should be considered to uncover a possible appendiceal NET G1 (carcinoid), particularly when dilatation of the distal lumen is kept under observation.
Department of Gastroenterology, Yokohama Clinic, Kanagawa Dental University, 3-31-6 Tsuruya-cho, Kanagawa-ku, Yokohama, Japan. aozora1@himawarifukushi.or.jp.|Kohnan Aozora, Facility for the Elderly, 2187-1 Noba-cho, Kohnan-ku, Yokohama, 234-0056, Japan. aozora1@himawarifukushi.or.jp.
Hiroyuki A
HA
Watanabe
Department of Surgery, Hiratsuka Gastroenterological Hospital, Tokyo, Japan.
Taketoshi
T
Fujimoto
Department of Pathology, Nikko Medical Center, Dokkyo Medical University, Nikko, Japan.
Yo
Y
Kato
Department of Radiology, Shiseikai Daini Hospital, Tokyo, Japan.
Mayumi
M
Sasaki
Department of Internal Medicine, Showa University Northern Yokohama Hospital, Yokohama, Japan.
Toshikazu
T
Ikusue
D000208:Acute Disease; D000328:Adult; D001062:Appendectomy; D001063:Appendiceal Neoplasms / Q000150:complications* / Q000000981:diagnostic imaging / Q000473:pathology; D001064:Appendicitis / Q000209:etiology* / Q000628:therapy; D002276:Carcinoid Tumor / Q000150:complications* / Q000000981:diagnostic imaging / Q000473:pathology; D000072700:Conservative Treatment; D006801:Humans; D007414:Intestinal Neoplasms / Q000150:complications* / Q000000981:diagnostic imaging / Q000473:pathology; D008297:Male; D014057:Tomography, X-Ray Computed; D014463:Ultrasonography
Appendicitis; Interval appendectomy; NET G1 (carcinoid)