Adult pancreatoblastoma: Current concepts in pathology

Abstract

Adult pancreatoblastoma is an exceptionally rare malignant tumour of the pancreas that mimics other solid cellular neoplasms of the pancreas, which may pose diagnostic difficulties. Because of its rarity, little is known about its clinical and pathologic features. This article reviews the clinical and pathologic features of pancreatoblastoma in adults including differential diagnosis, treatment, and follow-up. Although pancreatoblastoma commonly occurs in childhood, there have now been more than 70 adult pancreatoblastomas described in the literature. There is a slight male predominance. There are no symptoms unique to pancreatoblastomas and adult patients are frequently symptomatic. The most common presenting symptom is abdominal pain. Grossly, the tumours are often large and well-circumscribed. Microscopically, pancreatoblastomas are composed of neoplastic cells with predominantly acinar differentiation and characteristic squamoid nests. These tumours are positive for trypsin, chymotrypsin, lipase, and BCL10. Loss of heterozygosity on chromosome 11p is the most common molecular alteration in pancreatoblastomas. Adult pancreatoblastomas are aggressive tumours with frequent local invasion, recurrence, and distant metastasis. Treatment consists of surgical resection. Chemotherapy and radiotherapy may have a role in the treatment of recurrent, residual, unresectable, and metastatic disease. It is important to distinguish pancreatoblastomas from morphological mimics such as acinar cell carcinomas, solid pseudopapillary neoplasms, and pancreatic neuroendocrine neoplasms.

Solid pseudopapillary neoplasm of the pancreas

“…Pancreatoblastoma is a malignant epithelial tumour composed of neoplastic cells showing predominantly acinar differentiation with characteristic squamoid nests. Although pancreatoblastomas frequently occur in childhood, they can be seen in adults[ 33 , 34 , 35 ]. Pancreatoblastomas exhibit malignant behaviour with local infiltration of adjacent structures and distant metastasis at the time of diagnosis or afterwards in the course of the disease[ 33 , 34 , 35 ].…”

“…Although pancreatoblastomas frequently occur in childhood, they can be seen in adults[ 33 , 34 , 35 ]. Pancreatoblastomas exhibit malignant behaviour with local infiltration of adjacent structures and distant metastasis at the time of diagnosis or afterwards in the course of the disease[ 33 , 34 , 35 ]. Both pancreatoblastomas and solid pseudopapillary neoplasms are solid cellular tumours of the pancreas.…”

“…Both pancreatoblastomas and solid pseudopapillary neoplasms are solid cellular tumours of the pancreas. The features that favour a diagnosis of pancreatoblastomas include predominant acinar units, squamoid nests, prominent central nucleoli, granular eosinophilic cytoplasm containing DPAS-positive zymogen granules, and immunolabelling for trypsin, chymotrypsin, BCL10, and lipase[ 2 , 33 , 35 ].…”

Up-regulation of ALK is associated with altered Wnt/beta-catenin pathway in adult pancreatoblastoma

“…1 In adults, approximately 70 cases have been reported. 2 Pancreatoblastoma usually presents as a large solitary mass that is wellcircumscribed or encapsulated. Histologically, it is composed of cellular lobules of epithelial cells with solid, trabecular or acinar architecture.…”

“…Data from reported cases in the literature show that at least half of the patients died of disease at mean follow-up of 27 months. 2 Given the poor survival in adult pancreatoblastoma, immunotherapies may be a rational therapeutic option.…”