Calcitonin gene-related peptide (CGRP) is reported to exist in high concentrations in plasma and tumor tissues of medullary thyroid carcinomas. CGRP-like immunoreactivity (LI) in tumor tissues of pheochromocytomas was investigated by radioimmunoassay. CGRP-LI in 9 pheochromocytomas ranged from 0.50 to 1240 ng/g wet tissue. Sephadex G-50 column chromatography revealed that most of CGRP-LI in tumor extracts was eluted in an identical position to synthetic human CGRP. Reverse-phase high pressure liquid chromatography revealed that CGRP-LI in tumor extracts was eluted in an identical position to synthetic human CGRP and in a more hydrophobic position. These results indicate that high concentrations of CGRP-LI also exist in tumor tissues of pheochromocytomas.

Adrenal Gland Neoplasms↗

PubMedDate not supplied

Melanin-concentrating hormone in the human brain.

The presence of human melanin-concentrating hormone (MCH) was studied in the human brain by radioimmunoassay and immunocytochemistry. Immunoreactive MCH concentrations in the human brain ranged from 0.07 to 19.7 pmol/g wet weight. High performance liquid chromatography of the hypothalamus showed a large immunoreactive peak in the position of human/rat MCH, which was eluted 9 min later than that of salmon MCH. Free-floating sections (40 microns) of the hypothalamus were immunostained. Positive MCH immunostaining was found in perifornical, tuberomammillary, and posterior nuclei. Numerous MCH-immunoreactive nerve fibers were observed throughout the hypothalamus. The presence of high concentrations of MCH in the human brain, in particular in the hypothalamus, suggests that MCH is a neurotransmitter, a neuromodulator, or a neurohormone in man.

Aged↗

PubMedDate not supplied

Melanin-producing medullary thyroid carcinoma with glandular differentiation.

A rare case is reported of melanin-producing medullary thyroid carcinoma in a 62-year-old man. Intraoperative imprints of the thyroid tumor revealed numerous detached tumor cells containing large amounts of brown pigment. The Fontana-Masson argentaffin reaction with bleach confirmed that those granules were melanin. Histologically, the tumor was composed of two different components--a medullary area with hyalinized stroma and a follicular area. Melanin was scattered in both areas. The tumor cells in both areas were immunoreactive to carcinoembryonic antigen, calcitonin, gastrin-releasing peptide, somatostatin, met.-enkephalin, neuron-specific enolase, chromogranin and neurofilaments, and negative for thyroglobulin and S-100 protein. The histologic diagnosis was melanin-producing medullary thyroid carcinoma with glandular differentiation. Although various kinds of peptides and amines have been reported to be produced in medullary thyroid carcinoma, melanin production is quite rare; this appears to be only the third reported case.

Carcinoma↗

PubMedDate not supplied

Peritoneal implantation of endodermal sinus tumor of the pineal region via a ventriculoperitoneal shunt. Cytodiagnosis with immunocytochemical demonstration of alpha-fetoprotein.

A 17-year-old male developed an endodermal sinus tumor in the pineal region that metastasized to the peritoneal cavity via a ventriculoperitoneal shunt and caused ascites. Neoplasm was diagnosed by cytologic examination of the peritoneal fluid, and the precise histologic nature of the neoplasm was confirmed by immunocytochemistry, which demonstrated alpha-fetoprotein in the neoplastic cells.

Adolescent↗