Exocrine tumors / carcinomas

Author: Deepali Jain, M.D. (see Authors page)

Revised: 18 December 2017, last major update August 2012

Copyright: (c) 2002-2017,, Inc.

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

Cite this page: Jain, D. Pancreatoblastoma. website. Accessed October 24th, 2018.
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

Images hosted on PathOut server:

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