Abstract
A case of adenocarcinoma of the head of the pancreas in a 13-year-old girl is reported. Some areas simulated an islet cell tumor by light microscopy, but contained numerous eosinophilic granules which were PAS-positive and diastase resistant. Ultrastructurally, the granules were large (960 μm–3000 μm in diameter) and electron-dense, resembling zymogen granules. These granules often showed focal to complete degeneration, occassionally being continuous with a myelin figure. The granules of true islet cell tumors are ultrastructurally distinctive and it is urged, therefore, that all pancreatic neoplasms in children be studied by histochemistry and electron microscopy. Carcinoma of the pancreas in childhood is a rare tumor, often with a rapid clinical course resulting in death. Morphologic separation of cases reported in the English language literature can be made on the basis of acinar differentiation. This feature has been suggested as a peculiarity of childhood pancreatic carcinoma. However, there is a suggestion that this phenomenon occurs in a small percentage of adult tumors as well. More extensive morphologic studies in adult pancreatic cancer may be warranted.