A Case of Nonfunctioning Islet Cell Tumor Assessed Malignancy by Measuring the Nuclear DNA Content with a Flow Cytometer

Takayuki Suto¹⁾, Sadahide Ono¹⁾, Kosuke Sasaki¹⁾, Tamotsu Sugai²⁾, Ryoko Sasaki³⁾, Yoshiyuki Tamasawa³⁾, Hidehiro Tyoshima³⁾, Hidetoshi Omori³⁾, Tadashi Abe³⁾, Senji Kanno³⁾, Kazuyoshi Saito³⁾, Hidehumi Shimotono⁴⁾

Department of Pathology I¹⁾, Division of Pathology Central Clinical Laboratory²⁾, Departments of Surgery I³⁾and Medicine I⁴⁾, Iwate Medical University School of Medicine

A 60-year-old man without any clinical symptoms was found to have liver dysfunction by mass screening examination. Distal pancreatectomy was carried out under a preoperative diagnosis of pancreatic tail tumor. No clinical symptoms due to hormonal hypersecretion were recognized, but argyrophilic granules were demonstrated by Grimelius staining, and immunohistochemical staining showed positive immunoreactivity for chromogranin and neuronspecific enolase. Because ultrastructural examination revealed tumor cells with secretory granules, and the tumor showed vascular invasion, a diagnosis of nonfunctioning islet cell carcinoma was made. We measured the nuclear DNA content of the cancer cells with a flow cytometer. Nine of 11 samples showed aneuploidy (DI=1.36), and in other parts two different aneuploid lines (DI=1.36, 1.55) were disclosed in the same sample. The histologic diagnosis was supported by flow cytometric DNA analysis. However, the small fraction of S-phase cells suggests low proliferative activity of the tumor.

Key words
nonfunctioning islet cell tumor, flow cytometry

Reprint requests
Takayuki Suto First Department of Pathology, Iwate Medical University School of Medicine
19-1 Uchimaru, Morioka, 020 JAPAN

Accepted
October 9, 1991

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