title: A minute nonfunctioning islet cell tumor demonstrating malignant features.
abstract: We report a patient with a minute nonfunctioning islet cell tumor, 8 mm in diameter, which demonstrated malignant features by histology. The patient was a 43-year-old Japanese woman, who had an elevated carbohydrate antigen (CA) 19-9 level, of 59 U/ml (normal range, <37 U/ml) identified on a health check to rule out malignancies. Ultrasonography and computed tomography demonstrated a well-defined pancreatic tumor, 8 mm in diameter, in the body of the pancreas. Serum levels of pancreatic hormones were within normal limits, and thus a tentative diagnosis was nonfunctioning islet cell tumor. The size of the tumor remained unchanged for 1 1/2 years, but, at this time, the serum level of CA19-9 was elevated to 253 U/ml. Segmental pancreatectomy was performed because malignancy could not be ruled out. The resected specimen showed an endocrine tumor invading both the pancreatic parenchyma and the perineural spaces outside the tumor. In general, minute nonfunctioning islet cell tumors have been considered to be completely benign, but the present tumor showed clear malignant features. We might have to take surgical resection into consideration even if the size of such an endocrine tumor is minute.
authors.affiliation: Department of Surgery and Oncology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Ikenaga
authors.forename: Koji
authors.initials: K
authors.lastname: Yamaguchi
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Konomi
authors.forename: Kei
authors.initials: K
authors.lastname: Fujii
authors.forename: Atsushi
authors.initials: A
authors.lastname: Sugitani
authors.forename: Masao
authors.initials: M
authors.lastname: Tanaka
mesh_terms: D007516:Adenoma, Islet Cell / Q000175:diagnosis / Q000601:surgery*; D000328:Adult; D003937:Diagnosis, Differential; D003952:Diagnostic Imaging; D005260:Female; D006801:Humans; D010180:Pancreatectomy / Q000379:methods*; D010190:Pancreatic Neoplasms / Q000175:diagnosis / Q000601:surgery*