Hepatic Metastasis of Composite Adenocarcinoma and Neuroendocrine Carcinoma

Abstract

Composite glandular neuroendocrine tumors of the gastrointestinal tract are rare tumors. These dual-nature tumors can be divided into three subtypes: composite, collision, and amphicrine tumors. The term composite tumor applies to those neoplasms that contain intimately mixed glandular and neuroendocrine components. In collision tumors, the glandular and neuroendocrine components are closely juxtaposed but the individual cells are not mixed. Amphicrine carcinoma is applied when dual differentiation is present within the same cell [1]. Review of the English literature demonstrated sporadic case reports of composite tumors in the stomach, gallbladder, bile duct, pancreas, colon, and rectum [2–7]. In addition to the rarity of this lesion in the colon and rectum, to our knowledge, this is the first report of such colonic tumor to be diagnosed in the literature from the liver metastasis. The histogenesis of tumors containing both glandular and neuroendocrine components has generated much interest. Although it was not fully elucidated, recent molecular studies supported an origin from a multipotential stem cell for these tumors. The sequence of malignant progression is through adenoma to carcinoma with both glandular and neuroendocrine components sharing a common mechanism of carcinogenesis [1, 8]. Case Report