motilin and Liver-Neoplasms

Motilin-secreting neuroendocrine tumours have been rarely described. Immunohistochemical, biochemical and motility investigations were performed in a 62-year-old man with liver and bone metastases of a motilin-secreting neuroendocrine tumour originating from a rectal polyp removed 14 years previously. Symptoms related to liver metastases were reduced by a right hepatectomy whereas plasma motilin levels were decreased. The patient also underwent two operations for spinal cord decompression and survived 6 more years under medical treatment, mainly octreotide. Immunohistochemistry revealed predominant expression of motilin-containing cells, with rare cells expressing somatostatin and pancreatic polypeptide, and staining for only one panendocrine marker, neurone-specific enolase. A liver tumour extract contained 17.9 microg motilin per gram of tissue, which permitted to isolate and characterize human motilin, which was identical to porcine motilin. Plasma column gel chromatography revealed a main peak corresponding apparently to porcine motilin. The patient had no symptoms of disturbed motility. Gastric emptying and gastroduodenojejunal motility were found within normal limits. The absence of alterations of gut motility was perhaps related to sustained autonomous motilin production. The long evolution of this type of tumour suggests that plasma motilin determination should be added to the investigations for neuroendocrine tumours.

Topics: Bone Neoplasms; Disease-Free Survival; Humans; Liver Neoplasms; Male; Middle Aged; Motilin; Neuroendocrine Tumors; Rectal Neoplasms; Time Factors

A 62-year-old man with a history of a resected rectal polyp was diagnosed 14 years later with right liver and multiple bone metastases. The liver biopsy showed a malignant epithelial tumor that was positive for neuron-specific enolase immunostaining and negative for chromogranin. Electron microscopy was characteristic of that for an endocrine tumor. Most circulating hormonal peptide levels were within normal ranges and only motilin level was elevated. On the right hepatectomy, the three large metastases had a histologic picture suggestive of an endocrine tumor. Immunohistochemistry revealed in some areas numerous tumor cells expressing motilin, and a few cells were strongly positive for pancreatic polypeptide and somatostatin. The retrospective analysis of the rectal polyp showed a similar histology and immunohistochemical profile, indicating that this lesion was the primary tumor. Motilin-positive cells from one of the hepatic lesions were identified on semithin sections and further processed for electron microscopy. Neurosecretory granules were numerous in all cells. Immunoelectron localization enabled us to characterize the motilin-containing neurosecretory granules, which had a mean diameter of 168.3x38.1 nm. Although not all tumor cells were motilin-positive, a diagnosis of motilinoma for the rectal polyp and its hepatic and bone metastases was proposed.

Topics: Biopsy; Bone Neoplasms; Carcinoid Tumor; Cytoplasmic Granules; Humans; Immunohistochemistry; Liver Neoplasms; Male; Microscopy, Immunoelectron; Middle Aged; Motilin; Polyps; Rectal Neoplasms; Time

The acid extract of a liver metastasis from a patient with elevated plasma motilin levels contained large quantities of motilin (3.37 micrograms/ml). The extract was concentrated on a C18-column and motilin was isolated by gel chromatography (Sephadex G-50) followed by cation ion exchange chromatography (HR5/5 Mono-S) and three successive steps of reverse phase chromatography (Nucleosil 300-5 C18). The pure peptide was sequenced and the identity of porcine and human motilin was confirmed. This is the first report of a tumor containing large amounts of motilin.

Topics: Amino Acid Sequence; Base Sequence; Carcinoid Tumor; Chromatography; Gastrointestinal Motility; Humans; Liver Neoplasms; Molecular Sequence Data; Motilin; Radioligand Assay; Sequence Homology, Amino Acid