Aregntaffin carcinoid tumor of the rectum

Abstract

A case of rectal carcinoid tumor in a 79-year-old Japanese man is reported. The tumor, 1.5 x 0.9 cm, was localized in both mucosa and submucosa of the rectum with neither invasion nor metastasis. Microscopically, neoplastic cells were mainly arranged in rosette-like and trabecular structures within thin fibrous stroma. Histochemically, both argyrophil and argentaffin reactions were positive. At the ultrastructural level, two distinctive types of neurosecretory granules were found in the cytoplasm of tumor cells.

Multiple malignant rectal carcinoid tumors with immunocytochemical demonstration of multiple hormonal substances

“…There is only one case report of a rectal carcinoid tumor seemingly as strongly argentaffin as the one reported here. 24 The neoplasms reported in this paper were positive for glucagon-like somatostatin, and serotonin immunoreactivity. Others have reported rectal carcinoids to contain glucagon and somatostatin in 15% to 48%3 and in 24% to 38%20 of cases, respectively.…”

Revised classification of neuroendocrine tumours of the lung, pancreas and gut

“…To date, there is only one report of a rectal trabecular neuroendocrine tumour in which motilin cells represented the prevailing cell population [49]. Argentaffin EC cell tumours, with characteristic insular pattern and serotonin production, are extremely rare in the rectum [132], while they represent the most frequent type of neuroendocrine tumours in the colon with prevalence for the caecum [11].…”

Pathology and Nomenclature of Human Gastrointestinal Neuroendocrine (Carcinoid) Tumors and Related Lesions

“…The EC cell tumors of the classic ''argentaffin'' carcinoid type, with characteristic insular pattern and serotonin production, are rare in the rectum [81,82]. These neoplasms are the most frequent type of neuroendocrine tumors in the colon, with greatest prevalence in the cecum [62].…”