Immunohistochemical and statistical studies on the islets of Langerhans pancreas in autopsied patients after gastrectomy.

We describe in detail the pathologic features of the islets of Langerhans in specimens of the pancreas from 75 autopsy specimens of patients who underwent gastrectomy and compare them with specimens from 22 patients not having gastrectomy with respect to the duration of the postoperative period and the operative procedure. In comparison with the control group, the islets of Langerhans from the gastrectomy patients showed hyperplasia and increased numbers of endocrine cells within 5 years of gastrectomy but atrophy and decreased numbers of endocrine cells thereafter. These changes are compatible with anti-insulin immunoreactivity (B-cells) in the islets of Langerhans, where B-cell counts correlated with the area of the islets. The proliferating cell nuclear antigen (PCNA)-positive cell ratio in the islets was higher during the early phase after gastrectomy, whereas the apoptotic cell ratio was not affected by the time after gastrectomy. Hyalinization of the islets of Langerhans was first recognized after 5 years postoperatively, and the percentage of hyalinization gradually increased. Amylin deposits, detected by immunostaining, increased progressively in the islets in relation to the duration of postoperative period, correlating inversely with B-cell count and PCNA positivity. These histologic changes suggest that B cells proliferated secondary to oxyhyperglycemia in the early phase after gastrectomy followed by the state of waste, finally resulting in atrophy and amylin deposits, which led to hypofunction of the islets of Langerhans with resultant glucose intolerance. HUM PATHOL 31:1368-1376.