Pancreas
Other tumors
Pancreatoblastoma
Author: Deepali Jain, M.D.
Topic Completed: 1 August 2012
Minor changes: 26 October 2020
Copyright: 2002-2021, PathologyOutlines.com, Inc.
PubMed Search: Pancreatoblastoma[TI] full text[sb]
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
Gross images
Images hosted on other servers:
Encapsulated heterogeneous mass with cystic components
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
Mixed solid glandular pattern
Solid tumor with scattered squamoid corpuscles
Spindle cells with sarcomatoid features
Chondroid tissue surrounded by spindle cells
Nests of squamous or epidermoid tissue
Spindle cells,
epithelial cells
and osteoid
CAM5.2+ tumor cells in acinar pattern
Tumor cells grow in acinar pattern
Images hosted on other servers:
Squamoid nests
Various images
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
