acid-phosphatase and Malignant-Carcinoid-Syndrome

Platelets and megakaryocytes from 11 patients with the carcinoid syndrome have been studied by transmission electron microscopy. Cells fixed in phosphate-buffered glutaraldehyde are oval to discoid, with pseudopods, a dilated open-channel system, and a prominent dense tubular system as defined by peroxidase activity and alkaline bismuth stain. Atypical with hexagonal lattices and treaded substructures and large (diameter greater than 0.5 mum), phosphatase-positive, debris-containing vacuoles are four times more numerous than in normal platelets. Incubation of platelets in a 0.05% suspension of latex results in particle incorporation into phagosomes and the debris-containing vacuoles. Molybdate-dichromate stain reveals two classes of dense bodies, one of which (with a reticular core) is 20 times more numerous than in normal platelets. Bone marrow megakaryocytes lack both dense bodies and debris vacuoles analogous to those found in circulating platelets. These results suggest autophagy or endocytosis abnormalities and provide evidence for multiple types of dense bodies in carcinoid platelets.

Topics: Acid Phosphatase; Aged; Blood Platelets; Cytoplasmic Granules; Female; Histocytochemistry; Humans; Hydroxyindoleacetic Acid; Inclusion Bodies; Male; Malignant Carcinoid Syndrome; Megakaryocytes; Middle Aged; Neoplasm Metastasis; Phagocytosis; Serotonin; Vacuoles

A case of the carcinoid syndrome associated with a proximal myopathy is reported. Histology showed advanced atrophy of type II muscle fibres but no inflammation. Perinuclear acid phosphatase was increased. Electron microscopy revealed persistence of the Z-line until the muscle fibre had been severely disrupted. Similar lesions have been observed in the hereditary muscular dystrophy in mice, and also in these animals and in rats when injected with 5-hydroxytryptamine (5-HT). Treatment with cyproheptadine caused a documented response in the patient's debilitating diarrhoea and also produced symptomatic improvement in her muscular power. We suggest that the myopathy is due to circulating 5-HT or is a non-metastatic complication of the carcinoid tumour.

Topics: Acid Phosphatase; Cyproheptadine; Diarrhea; Feces; Female; Fenclonine; Humans; Hydroxyindoleacetic Acid; Malignant Carcinoid Syndrome; Microscopy, Electron; Middle Aged; Muscles; Muscular Diseases; Myofibrils

Topics: Acid Phosphatase; Adult; Albumins; Bile Acids and Salts; Carcinoma, Hepatocellular; Esterases; Fibrinogen; Glycogen; Histocytochemistry; Humans; Hydroxyindoleacetic Acid; Lipids; Lipoproteins; Liver Neoplasms; Lung Neoplasms; Male; Malignant Carcinoid Syndrome; Microscopy, Electron; Peroxidases; Serotonin; Staining and Labeling; Transferrin