Chromogranin A: belongs to a family of secretory proteins that are present in dense-core vesicles of neuroendocrine cells. Owing to its widespread distribution in neuroendocrine tissues, it can be used as an excellent serum marker of neuroendocrine activity because it is co-released with the peptide hormone content of the secretory granules. It has high specificity for detecting neuroendocrine tumors. It also has a high sensitivity to detect small tumor. The concentrationsof �Chromogranin A�, is elevated in 90% of patientswith neuroendocrine tumors. Serum �Chromogranin A� is mostfrequently increased in subjects with gastrinomas (100%), pheochromocytomas(89%), carcinoid tumors (80%), nonfunctioning tumors of theendocrine pancreas (69%), and medullary thyroid carcinomas (50%), small cell carcinomas of the lung (60%) and neuroblastoma in children (92%).The highest serum levels are
observed in subjects with carcinoidtumors. A significantpositive relationship was demonstrated between the tumor loadand serum �Chromogranin A� levels. Mild Elevated concentrationsof �Chromogranin A� has a specificity of 93%. Markedly elevated serum levelsof �Chromogranin A�, exceeding 300 �g/L, has a 98% specificity. If its concentration, in small cell carcinoma, is higher than 65 ng/ml, it is considered a bad independent prognostic marker. �Chromogranin A� is very helpful, not only in screening for neuroendocrine tumor mentioned above, but also is very helpful for detecting early recurrence
In Summary: �Chromogranin A� is the best general neuroendocrineserum marker available. It is very helpful in diagnosing and detecting the following tumors: Carcinoid tumors, pheochromocytoma, gastrinomas, islet cell tumors of the pancreas, medullary carcinoma of the thyroid, small cell carcinoma of the lung and neuroblastoma. It has the highest specificity for thedetection of neuroendocrine tumors compared to the other neuroendocrinemarkers (like NSE). The higher the tumor serum level is, the larger the tumor volume. Its level is important for detecting early recurrence of such tumors
In our effort to bring the best of clinical tests to medical practice in Jordan, we would like to announce that this test is available now in Jordan in our lab only
Please contact us for any further inquiries
Dr. Hussam Abu-Farsakh
American Boards of Anatomic and Clinical pathology and Cytopathology
Ref: Sch�rmann, G: Serum chromogranin A in the diagnosis and follow-up of neuroendocrine tumors of the gastroenteropancreatic tract. World Journal of Surgery 16 (4): pp 697-701