Pancreas
Exocrine tumors / carcinomas
Solid pseudopapillary tumor

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

Revised: 21 December 2017, last major update August 2012

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

PubMed Search: Solid pseudopapillary tumor[TI] pancreas[TI] free full text[sb]

Cite this page: Jain, D. Solid pseudopapillary tumor. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/pancreassolidpseudo.html. Accessed February 19th, 2018.
Definition / general
  • Low grade malignancy composed of poorly cohesive monomorphic epithelial cells forming solid and pseudopapillary structures (IARC: 8452 / 1 Solid Pseudopapillary Tumor [Accessed 21 December 2017])
  • Not truly papillary or truly cystic
  • Also called SPT, papillary and solid epithelial neoplasm, papillary cystic neoplasm, Gruber-Frantz tumor
  • 1 - 2% of nonendocrine pancreatic neoplasms
  • Mean age 30 - 35 years, 90% women, not associated with any clinical syndrome
Etiology
Radiology images

Images hosted on PathOut server:

CT scan

Poor prognostic factors
  • Venous invasion, high nuclear grade, "necrobiotic nests"
  • Metastases in 10 - 15% to liver or peritoneum are associated with venous invasion, high nuclear grade and necrosis
  • Patients usually survive even with metastases
Case reports
Treatment
Gross description
Gross images

Images hosted on PathOut server:

Multilocular cystic mass



Images contributed by Dr. Andreas Schulz, Giessen, Germany:

Whipple specimen showing
large, round, well demarcated
mass in head of pancreas; tumor
is partly necrotic and cystic



Images contributed by Dr. Manfred Stolte, Bayreuth, Germany:

Tumor invades spleen and gave rise to liver metastases



Images contributed by Dr. Helmut Luchtrath, Koblenz, Germany:

Cut surface shows
uniloculated cyst
with some solid
areas in capsule



Images hosted on other servers:

Solid mass

Microscopic (histologic) description
  • Cellular tumor, resembles pancreatic endocrine neoplasm or CNS ependymoma
  • Pseudopapillae with hyalinized fibrovascular cores lined by several layers of bland fragile epithelial cells with clear to eosinophilic cytoplasm, variable mucinous changes within the core, intracytoplasmic PAS+ hyaline globules
  • Pseudopapillae are due to solid nests minus cells degenerating away from the small vessels; resemble rosettes in cross section
  • Also round / oval nuclei, finely stippled chromatin, nuclear grooves, indistinct nucleoli, few mitoses
  • Also foam cells, clusters of lipid / cholesterol crystals surrounded by foreign body giant cells
  • May have pseudocystic areas
  • Tumor cells infiltrate without any stromal reaction
Microscopic (histologic) images

Images hosted on PathOut server:

Pseudopapillae

Solid monomorphous pattern with variable vacuoles and sclerosis

Nuclei lack
conspicuous
nucleolus but
show indentations

Cholesterol crystals
surrounded by
foreign body cells


Intense focal immunostaining for alpha-1-antitrypsin

Diffuse immunostaining for NSE

Tumor tissue (top) is sharply
demarcated from adjoining
pancreatic parenchyma (bottom)
but lacks a clear capsule

Margin of a malignant
tumor with deep invasion
into the adjacent
pancreatic tissue


Tumor cells radially arranged around
delicate and somewhat hyalinized
fibrovascular stalk; arrows point to small
hyaline globules within and between the cells

Solid part of tumor has aggregate of large
tumor cells with foamy cytoplasm (arrows);
arrowheads point to small cyst filled with
eosinophilic fluid and some foam cells



Case of the Week #121:

Various images


CD10+

CD56+

Vimentin+

PR+

Alpha-1-antitrypsin+



Images hosted on other servers:

Pseudopapillae

Various images

β catenin

Cytology description
  • Cellular, single cells, small loose clusters and scattered intact papillary structures with delicate fibrovascular cores, fibrovascular cores may contain metachromatic material and hyaline globules may be seen extracellularly, cells have delicate, finely granular cytoplasm (Korean J Pathol 2012;46:399)
  • Chromatin is fine and nuclei are frequently grooved
Cytology images

Images hosted on other servers:

Various images

Comparison with pancreatic neuroendocrine tumors


Immunostains

Positive stains
Negative stains
Electron microscopy description
  • Large electron dense granules with complex internal membranous and granular inclusions and alpha-1-antitrypsin
Electron microscopy images

Images hosted on PathOut server:

Images contributed by Dr. H.D. John, Mainz, Germany:

Tumor cells with abundant
cytoplasm containing multiple
mitochondria and a few dense
bodies; nuclei have a polygonal shape

Large osmiophilic, zymogen-like granules of variable sizes; often is disintegration of granule content, forming multilamellated vesicles

Molecular / cytogenetics description
  • Almost always mutations in exon 3 of the beta catenin gene, causes abnormal immunostaining patterns for beta catenin (nuclear and cytoplasmic, compared to membranous staining in normal pancreas) and overexpression of cyclin D1 (Am J Pathol 2002;160:1361)
Differential diagnosis
  • Acinar cell carcinoma: typically has acinar formations, prominent nucleoli and mitotic activity, trypsin+, chymotrypsin+, lipase+ (Mod Pathol 2007;20:S94)
  • Adrenal cortical tumors: positive for inhibin, keratin
  • Pancreatic endocrine tumor: no degenerative pseudopapillae, no clear cells, usually no intracytoplasmic hyaline globules, no longitudinal nuclear grooves; no nuclear β catenin staining, CD10- (Am J Surg Pathol 2011;35:981)
  • Pancreatic pseudocyst: may be grossly similar but no epithelial cells lining the cystic structures, even after careful search, patients are usually older and male and have a history of pancreatitis