Pancreas
Exocrine tumors / carcinomas
Pancreatoblastoma


Topic Completed: 1 August 2012

Revised: 28 January 2019

Copyright: (c) 2002-2019, PathologyOutlines.com, Inc.

PubMed Search: Pancreatoblastoma[TI] full text[sb]

Deepali Jain, M.D.
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Cite this page: Jain D. Pancreatoblastoma. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/pancreaspancreatoblastoma.html. Accessed October 19th, 2019.
Definition / general
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 tumor with nodular surface

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

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 in a
background of small,
diffusely infiltrating cells

Spindle cells (center),
epithelial cells (right)
and osteoid (left)

CAM5.2+ tumor cells
in acinar pattern;
squamoid corpuscles
do not stain

Tumor cells grow in acinar pattern and include groups of cells with pale cytoplasm ("squamoid corpuscles")



Images hosted on other servers:

Squamoid nests

Various images

36 year old woman: cords of primitive small cells differentiating into squamoid nests with central keratinization, with (left) and without (right) calcification


Metastases to liver: acinar pattern with squamous morule

Various immunostains

Cytology description
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
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