Rectal adenocarcinoid with lymph node metastasis

We describe a case of a rare variant of a rectal carcinoid tumor that showe d mucous gland differentiation accompanied by a lymph node metastasis with a histological appearance similar to that of the primary site. The tumor co nsisted of a typical argyrophilic carcinoid component and of goblet cell gl ands. The carcinoid component was positive for neuron-specific enolase, chr omogranin A and synaptophysin. The goblet cells stained positively with per iodic acid-Schiff (PAS) and alcian blue, and expressed carcinoembryonic ant igen, but were negative for neuroendocrine markers. This case suggests that carcinoid tumor can differentiate towards mucus glands, which can also be found in the metastatic site.