Serous Cystadenocarcinoma of the Pancreas

Definition

• Same histologic features as serous microcystic adenoma but with metastases or invasion of adjacent organs

Note:

• WHO 2010 defines requires distant metastases for this diagnosis but cites literature (Galanis 2007, King 2009) that defines malignancy as above
  • It appears that invasion of adjacent organs is predictive of (infrequent) later metastases
  • Even with distant metastases there are no reports of deaths due to carcinoma

Diagnostic Criteria

• Same histologic features as serous microcystic adenoma
  • Innumerable small cysts
    • Most 1-5 mm
      • Scattered larger cysts
    • Sponge-like / honeycomb appearance
  • Lined by single layer of flattened or cuboidal cells with clear cytoplasm
    • Abundant glycogen (PAS +, diastase digestible)
    • Rarely eosinophilic cytoplasm
    • Occasional intracystic papillary projections
  • Bland cytology
    • Round/oval nuclei
    • No mitotic figures
    • At most, mild cytologic atypia
  • Central stellate scar frequently present
    • May calcify
    • Scant stroma otherwise
    • Occasionally entraps other elements
• Must demonstrate vascular invasion, metastases or invasion of adjacent organs (see note at top)
  • May be otherwise circumscribed
  • Most metastases reported to local lymph nodes and liver
  • Commonly invaded organs include spleen and stomach
• Rare cases have been reported of resected non-invasive serous cystadenomas that recurred later with metastases
• No deaths reported due to carcinoma

Robert V Rouse MD
Department of Pathology
Stanford University School of Medicine
Stanford CA 94305-5342

Original posting, updates: 1/4/07, 1/4/12

Supplemental studies

Histochemistry

Immunohistology

• Few cases reported
  • Keratin, EMA positive
  • Neuroendocrine markers negative

Differential Diagnosis

• Serous microcystic adenoma
• Serous oligocystic adenoma

Serous Microcystic Adenoma	Serous Cystadenocarcinoma of the Pancreas
Circumscribed intrapancreatic mass	Requires vascular invasion, adjacent organ invasion or metastases

Serous Macrocystic / Oligocystic Adenoma	Serous Cystadenocarcinoma of the Pancreas
Mass limited to pancreas, without vascular invasion	Requires vascular invasion, adjacent organ invasion or metastases

Clinical

• Mean age in 60's
  • Rare under age 20
• Even with invasion of adjacent organs, the primary masses in all reported cases have been resectable
• Rare cases have been reported of resected non-invasive serous cystadenomas that recurred years later with metastases
• No deaths due to neoplasm have been reported

Grading / Staging / Report

• Grading
  • All are histologically low grade
• Staging
  • No staging scheme described
• Report
  • Comment on rarity of lesion
  • Distinguish clearly from usual ductal carcinoma
  • Note that no deaths have been reported, even in the presence of metastases
  • Full range of potential behavior is not known

Lists

Cystic Pancreatic Lesions

• Acinar cell cystadenocarcinoma
• Acinar cell cystadenoma
• Enterogenous duplication cyst
• Epidermoid cyst in intrapancreatic accessory spleen
• Intraductal oncocytic papillary neoplasm
• Intraductal papillary mucinous neoplasm
• Islet cell / well differentiated neuroendocrine tumor (occasionally cystic)
• Lymphangioma
• Lymphoepithelial cyst
• Mucinous cystic neoplasm
• Paraduodenal wall cyst
• Pseudocyst
• Serous cystadenocarcinoma
• Serous oligocystic adenoma
• Serous microcystic adenoma
• Solid and cystic hamartoma
• Solid pseudopapillary neoplasm
• Squamoid cyst of pancreatic ducts
• von Hippel Lindau associated cystic lesions

Bibliography

• Bosman FT, Carneiro F, Hruban RH, Thiese ND (Eds). WHO Classifiication of Tumors of the Digestive System, IARC, Lyon 2010.
• Solcia E, Capella C, Kloppel G . Tumors of the Pancreas, Atlas of Tumor Pathology, AFIP Third Series, Fascicle 20, 1997.
• Shintaku M, Arimoto A, Sakita N. Serous cystadenocarcinoma of the pancreas. Pathol Int. 2005 Jul;55(7):436-9.
• Friebe V, Keck T, Mattern D, Schmitt-Graeff A, Werner M, Mikami Y, Adam U, Hopt UT. Serous cystadenocarcinoma of the pancreas: management of a rare entity. Pancreas. 2005 Aug;31(2):182-7.
• King JC, Ng TT, White SC, Cortina G, Reber HA, Hines OJ. Pancreatic serous cystadenocarcinoma: a case report and review of the literature. J Gastrointest Surg. 2009 Oct;13(10):1864-8.
• Galanis C, Zamani A, Cameron JL, Campbell KA, Lillemoe KD, Caparrelli D, Chang D, Hruban RH, Yeo CJ. Resected serous cystic neoplasms of the pancreas: a review
  of 158 patients with recommendations for treatment. J Gastrointest Surg. 2007 Jul;11(7):820-6.