Mucinous Cystic Neoplasm of the Pancreas
Definition
- Cystic mucinous neoplasm with ovarian type stroma and lacking communication with the pancreatic ducts
Alternate/Historical Names
- Mucinous cystic tumor
Diagnostic Criteria
- Grossly or radiographically visible lesion
- 95% in body or tail of pancreas
- Usually multilocular
- Cysts variably sized
- Usually 1 to several cm
- Frequently one dominant thick walled cystic structure
- Frequently contains multiple smaller daughter cysts in wall
- Cysts variably sized
- Lined by tall columnar cells
- Basal nuclei
- Abundant intracellular mucin
- Mucin may be depleted in high grade lesions
- May be partially denuded or lined by atrophic cells
- Goblet cells frequently admixed
- Scattered neuroendocrine cells in half of cases
- Focal gastric, intestinal or squamous differentiation may be seen
- Varying degrees of cytologic atypia and architectural complexity
- See Grading
- Ovarian type stroma
- Inner layer moderately to densely cellular
- Spindled cells with bland round to oval nuclei
- May be luteinized
- May be sparse or absent in patients >60
- May be sparse in large lesions
- Outer layer densely collagenous
- May calcify
- Inner layer moderately to densely cellular
- Lacks communication to pancreatic ducts
- Virtually all cases in females
- Separated into adenoma grade, borderline grade, carcinoma in situ grade
- See Grading for specific features
- Up to 1/3 have associated carcinoma
- Usually ductal
- Not colloid (mucinous)
- Entire lesion should be submitted to evaluate for associated carcinoma
- Unusual if lesion < 3cm
- Rare cases with sarcomatous stroma
- With or without heterologous elements
Robert V Rouse MD
Department of Pathology
Stanford University School of Medicine
Stanford CA 94305-5342
Original posting/last update: 2/1/07, 1/17/115