Route of FNAB with mucin subtype | Reported interpretation* |
Transgastric with neutral mucin | Could support origin from an MCL but cannot exclude contamination from gastric mucosa |
Transgastric with acidic or mixed mucin | Supports origin from an MCL |
Transduodenal with neutral or mixed mucin | Supports origin from an MCL provided neutral mucin is not contamination from Brunner’s glands |
Transduodenal with acidic mucin | Could support origin from an MCL but cannot exclude contamination from duodenal mucosa |
*Presence of unequivocal dysplasia or ‘mismatched epithelial mucin’ (see main text) overrides these interpretations and is regarded to indicate origin from an MCL.
EUS-FNAB, endoscopic ultrasound-guided fine-needle aspiration biopsy; MCL, mucinous cystic lesion.