Pancreatoblastoma a histochemical and ultrastructural analysis

Abstract

A case of pancreatoblastoma in a 4‐year‐old boy is presented. This tumor was studied by histochemical and ultrastructural techniques and was found to have both exocrine and endocrine components. This analysis and a review of the literature helps to further define this entity, which has a significantly better prognosis than other pancreatic malignancies.

Nonductal neoplasms of the pancreas

“…79 AFP is expressed in some pancreatoblastomas, typically those with serum elevations. 142,143,[152][153][154][155][156][157] Ultrastructural examination of pancreatoblastomas confirms the presence of acinar differentiation, with zymogen granules and irregular fibrillary granules that are somewhat less abundant than in acinar cell carcinomas. Some cases also have ultrastructural evidence of endocrine and ductal differentiation (neurosecretory and mucin granules).…”

“…Some cases also have ultrastructural evidence of endocrine and ductal differentiation (neurosecretory and mucin granules). 79,117,143,145,152,159 The molecular alterations in pancreatoblastoma are similar to those of hepatoblastoma and acinar cell carcinoma. 151 The most common genetic alteration identified to date is LOH of the short arm of chromosome 11p.…”

“…79,[139][140][141][142][143]145,146 Like acinar cell carcinomas, pancreatoblastomas can have serum elevations in AFP. 142,143,[152][153][154][155][156][157] Pancreatoblastomas average 10.6 cm and arise in the head and the tail of the gland with equal frequencies. 79,[139][140][141][142][143]145,146 Pancreatoblastomas are usually well-circumscribed and lobulated, soft, and fleshy on cut section.…”

Alpha fetoprotein-producing acinar cell carcinoma of the pancreas showing multiple lines of differentiation

“…AFP-producing tumours of the stomach can histologically mimic hepatocellular carcinoma and have therefore been named hepatoid adenocarcinoma [11]. Among pancreatic malignancies, AFP has been demonstrated in pancreatoblastomas [1,22] and ACCs [8,12,14,20], but rarely in other tumours [10]. Experimentally Rao et al [27] induced the appearance of hepatocyte-like cells (pancreatic hepatocytes) in the rat pancreas.…”

“…This tumour has to be included in the differential diagnosis of ACC, as it secretes AFP and endocrine and ductal differentiation are found in half the cases [1,22]. Because of these similarities, differential diagnosis between ACCs and pancreatoblastomas may be very difficult in the absence of squamoid corpuscles, which are a hallmark [14].…”