Small intestinal atypical carcinoid tumour with clear cell features: a case report and its differential diagnosis


Session type:

Jose Caduhada, Arlene De Luna

Philippine Heart Center, Quezon City, Philippines


Carcinoids are rare, slow growing tumours that arise from neuroendrocrine cells which involve many organds and most frequently the gastrointestinal tract. Common morphology and patterns are solidnests, trabecular, tubular, atypical, or poorly differentiated and mixed. Clear cell types have been described without atypia.

The objective of this report is to present an unusual multifocal carcinoid tumour with atypia and clear cell changes. The patient was a 75 year old hypertensive male with anemia due to blood loss secondary to lower GIT bleeding from polyps, which was not usual for carcinoid tumours. The differential diagnosis included poorly differentiated adenocarcinoma, paraganglioma, including gangliocytic type, metastasitc clear cell tumours aside from the adenocarcinoids and clear cell carcinoids. The clinical presentation of GI bleeding and histologic patterns mimicked closely of that of paraganglioma. The diagnosis of atypical carcinoid with clear cell features was achieved using mucicarmine, PAS stain and immunostains using cytokeratin, NSE and chromogranin. Co-morbid conditions in this patient such as hypertension, intestinal irritation due to bleeding were believed to mask the symptoms of a possible carcinoid syndrome.