Carcinoid tumor in a Meckel's diverticulum: hypothesis on mutual embryological origin.

Congenital defects presenting at an adult age are subject to diagnostic errors because of their relative rarity and often odd clinical presentation. We illustrate a 63-year-old male patient with multiple ileal carcinoid tumors along with a carcinoid tumor in Meckel's diverticulum. The Meckel's diverticulum is a congenital abnormality arising from a patent vitelline duct and is found at the anti-mesenteric side of the ileum. In the Meckel's diverticulum, ectopic tissue or neoplasms are sometimes found, which may lead to intussusception, hemorrhage, or inflammation. The carcinoid tumor is a neuroendocrine neoplasm originating from the neural crest and is diagnosed at virtually all ages. It may exhibit malignant behavior but generally has a mild clinical course. It is most often found in endodermally derived organs, especially the digestive and pulmonary tracts, and coexists frequently with malignant tumors, predominantly of endodermal origin such as colorectal carcinoma. The carcinoid tumor and Meckel's diverticulum are known to coincide, whereas the carcinoid is not really considered to be an embryologically determined defect. We hypothesize that both lesions are derived from local erroneous interaction among the neural crest and the endoderm.

Carcinoid tumor of the sacrum: case report.

We present a case of isolated carcinoid tumor of the sacrum and highlight the unusual nature of this lesion. The histopathology suggests hindgut cause, and we discuss the possibility of an underlying congenital tailgut cyst. We review the pathology of these rare anomalies with reference to embryological development and known instances of carcinoid focus. We also present previous reports of sacral carcinoid.

Neurocrest and colonic tumors: new clinical syndrome. Report of three cases.

This report describes three patients with both multiple intestinal polyps and tumors of neural crest origin. This combination of findings may represent a new clinical syndrome. The embryologic relationships between tumors derived from endoderm and tumors derived from neurocrest are described. An inherent defect in tissue proliferation or repair is postulated to explain the abnormal growth in these two different cell lines.

[Association of Recklinghausen's disease with carcinoid of Vater's ampulla. A new nosologic entity: apudoma. A case]. / Association maladie de Recklinghausen et carcinoïde de l'ampoule de Vater. Une nouvelle entité nosologique: les apudomes. Une observation.

The coexistence of neurofibromatous skin lesions and carcinoid of Vater's ampulla is not fortuitous. The melanocytes in the brownish pigmented skin lesions bind DOPA, while the chromaffin cells in the digestive tumour contain cytoplasmic granules where precursors of amines with digestive activity are synthetized and stored. DOPA is one of these precursors. Both diseases, therefore, are interrelated by a common embryological origin: the neural crest.

[The diffuse endocrine system and the carcinoids of the alimentary tract. Part I: Orthological aspects and common morphological features of the carcinoids (author's transl)]. / Das diffuse endokrine System und die Karzinoide des Gastrointestinaltraktes. Teil 1: Orthologische Gesichtspunkte und allgemeine Pathologie der Karzinoide.

Carcinoids arise from the so-called system of diffuse clear cells. Because of common histochemical properties it was proposed in the APUD-concept that these endocrine cells are of neural crest origin. As for the gastrointestinal tract endocrine cells this embryological derivation is disputed. Modern methods have led to the identification of about 18 distinct cell types. - According to the different localization of these cells in the alimentary canal the carcinoids show various histological structures i.e., a solid, trabecular, adenoid, undifferentiated and mixed growth. According to the reactivity to silver salts one can distinguish argentaffin, argyrophil and argyrophobe carcinoids. Biochemically and immunohistochemically some carcinoids are multihormonal, while others show paraendocrine hormone production. Small cell anaplastic carcinomas with endocrine granules are highly malignant variants of the carcinoids. There may be a mixed endo- and exocrine (amphicrine) differentiation in normal cells and in the so-called mucicarcinoids.

Carcinoid tumor in retinitis pigmentosa.

A carcinoid tumor was discovered by chance in a 25-year-old woman with the dominant type of retinitis pigmentosa. Although a coincidental association cannot be ruled out, there is at least a possibility that the two diseases have a common embryologic origin.

Primary carcinoids of the ileum and rectum. A simultaneous occurrence.

A patient had a simultaneous occurrence of an ileal and a rectal carcinoid. The ileal carcinoid, occurring in an area derived from primitive midgut, was argentaffin-positive; the rectal carcinoid, occurring in an area derived from primitive hindgut, was argentaffin-negative. To my knowledge, this is the first reported case of simultaneous ileum and rectal carcinoids; its uniqueness tends to support the concept of heterogeneity of origin of carcinoids in embryologically distinct regions.