Table of Contents
Definition / general | Clinical features | Case reports | Gross description | Gross images | Microscopic (histologic) description | Microscopic (histologic) images | Cytology description | Positive stains | Negative stains | Electron microscopy description | Differential diagnosisCite this page: Jain D. Pancreatoblastoma. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/pancreaspancreatoblastoma.html. Accessed March 8th, 2021.
Definition / general
- Most common pancreatic tumor of infancy / early childhood, characterized by acinar differentiation, squamoid corpuscles, stromal bands (IARC: 8971 / 3 Pancreatoblastoma [Accessed 18 December 2017])
Clinical features
- Children: 50% cured after excision; most survive and do well with chemotherapy if no metastases but those with metastases often die
- Children: higher survival if complete resection; 5 year overall survival is 79% (Eur J Cancer 2011;47:2347)
- Adults: mean survival 18 months
Case reports
- 27 year old woman with breast, liver and lung metastases (JOP 2012;13:301)
Gross description
- Partially encapsulated, often lobulated, mean 10 cm
Microscopic (histologic) description
- Mixtures of acini, squamoid corpuscles and less commonly endocrine or ductal features
- Very cellular, uniform epithelial cells in sheets and nests with acini / ducts
- Squamoid corpuscles (circumscribed whorled nests of plump spindle cells with a squamous appearance and occasional keratinization) are common and specific; note: this indicates a growth pattern, not a line of differentiation
- Pediatric cases often have hypercellular stroma, occasionally with bone / cartilage
Microscopic (histologic) images
AFIP images
Images hosted on other servers:
Cytology description
- Cellular smears with both epithelioid (acinar or undifferentiated) and immature mesenchymal cells (Arch Pathol Lab Med 2009;133:388)
Positive stains
- Note: presence of optically clear nuclei may cause false positive immunohistochemical staining with ABC (biotin) technique
- Pancreatic enzymes in acinar areas, CEA and mucin in luminal secretions of small acini
- Also keratin, alpha fetoprotein (18%), aberrant (nuclear / cytoplasmic) expression of beta catenin in squamous morules
Negative stains
- Neuroendocrine markers (rare cells may be positive)
Electron microscopy description
- Acinar cell features
Differential diagnosis
- Acinar cell carcinoma: no squamous corpuscles
- Solid pseudopapillary neoplasm: pseudopapillae with hyalinized fibrovascular cores lined by several layers of bland fragile epithelial cells with clear to eosinophilic cytoplasm