Fundic Gland Polyp

Epidemiology:

Common sites:

Gross features:

• usually multiple in FAP patients
• smooth
• sessile

Histologic features:

• exclusive to oxyntic mucosa
• cystically dilated and architecturally irregular oxyntic glands
• may be microcystic configuration
• may show prominent budding
• lined by somewhat flattened parietal and chief cells and occasional mucinous foveolar cells
• inflammation typically absent or minimal
• surface and foveolar atrophy often
• dysplasia if present primarily occurs within the foveolar compartment
• should extend to the surface

Immunophenotype:

Marker:

Sensitivity:

Specificity:

Molecular features:

• Beta-catenin mutations

Other features:

• Most are sporadic
• FAP patients often have these
• 42% may have dysplasia
• Can progress to malignancy in this setting (rarely)
• may be associated with PPI therapy (controversial)

References:

• Robbins 2005
• Odze, Surgical Pathology of the GI Tract 2004