PANCREATOBLASTOMA IN AN ADULT - ITS SEPARATION FROM ACINAR CELL-CARCINOMA

Pancreatoblastomas are rare tumours, which usually occur in childhood. Here we describe a pancreatoblastoma in a 39-year-old woman. The tumo ur was located in the tail of the pancreas and consisted of cells form ing well-differentiated acinar structures and scattered solid componen ts (''squamoid corpuscles''). Immunocytochemically, the acinar compone nts were positive for pancreatic enzymes and pancreatic stone protein, while the cells of the ''squamoid corpuscles'' lacked these markers. There was no p53 over expression nor any mutation at codon 12 of the K i-ras oncogene. The main differential diagnosis of this tumour was aci nar cell carcinoma, because both tumours have a number of features in common (scattered solid components, positivity for pancreatic enzymes, lack of p53 overexpression and of Ki-ms mutation). Findings which dis tinguished the pancreatoblastoma and separated it from acinar cell car cinoma were the negativity of the solid components (''squamoid corpusc les'') for neuroendocrine markers and their very weak keratin positivi ty. As the patient is alive and well 30 months after tumour resection, this pancreatoblastoma also differs in biology from the usual acinar cell carcinoma.