Nonfunctioning Islet Cell Tumors of the Pancreas: Clinical, Imaging and Pathological Aspects in 16 Patients

Background: Nonfunctioning islet cell tumors (NFICTs) usually reach a large size prior to detection, at which stage patients have some symptoms or signs. Recently, NFICTs have been discovered in asymptomatic patients with increasing frequency owing to advances in diagnostic imaging techniques. This study investigated clinical, imaging and pathological features in recent cases of NFICT. Methods: The medical records, radiographs and pathological specimens of 16 patients with NFICT who were evaluated between April 1991 and March 1996 were reviewed. Results: Tumor sizes ranged from 0.8 to 17 cm (average, 5.2 cm). Five patients (31%) had some symptoms or signs at the time of diagnosis; however, the other 11 (69%) had no symptoms. Of 10 patients with a tumor of size 5 cm or less, nine were asymptomatic and all tumors were histologically benign. In contrast, in six patients with a tumor larger than 5 cm, four had some symptoms and five tumors were malignant. The detection rates of pancreatic tumor mass on ultrasonography and computed tomography were 94% (15/16) each. All 14 patients in whom the tumor was completely resected survived without recurrence; however, the remaining two patients with liver metastases died following recurrence. Conclusions: US and CT are useful in detecting NFICTs even if the tumor is small and the patient is asymptomatic. The detection of NFICTs of small size and their complete removal are essential for a successful cure.