Capella et al classified mucinous carcinoma based on structural and cytological features as type A (paucicellular; a tumor showing a ribbon, annular or cribriform growth pattern with prominent extracellular mucin) and type B (hypercellular; a tumor showing clump- or sheet-like structures with reduced extracellular mucin) (15). Here, MUC5AC is linked to mucinous adenocarcinoma.