The present study provides guide lines for the diagnosis of adrenal medullary tumors in Egyptian patients. This retrospective study included, 73 cases of adrenal medullary tumors (39 pheochromocytoma, 13 neuroblastoma, 12 ganglioneuroblastoma and 9 ganglioneuroma) admitted to Mansoura Urology and Nephrology Center, Egypt.. All tumors were studied histologically and immunohistochemically. In pheochromocytomas, 33 patients became normal after 24 hours, the other 6 died from distant metastases. 6 patients with neuroblastoma and ganglioneuroblastoma were still living after adrenalectomy, while the other 19 patients received chemotherapy and were non-living after 24 months. Nine patients with ganglioneuroma were still living after adrenalectomy. All prepared slides were stained with periodic-acid Schiff’ reaction (PAS) and reticulin stains. Hyaline globules which were (PAS) positive were pheochromocytomas, while, they were not detected in neuroblastoma groups. All tumors were positive for reticulin stain. All cases of adrenal medulalry tumors were examined immunohistochemically using antibodies against chromogranin A, S-100 protein and neuron-specific enolase . Chromogranin A was expressed in all cases (39/39) pheochromocytoma, 5/13 neuroblastoma, 7/12 ganglioneuroblastoma and 7/9 ganglioneuroma. S-100 protein was expressed in 32/39 pheochromocytoma, 9/13 neuroblastomas, and all cases of ganglioneuroblastoma and ganglioneuroma. Neuron-specific enolase was expressed in all cases of pheochromocytoma, neuroblastoma, ganglioneuroblastoma and ganglioneuroma. The neuroendocrine tumors were stained with high specificity and sensetivity for the neuroendocrine markers; chromogranin A and neuron-specific enolase. Histomorphological features of benign and malignant pheochromocytomas may be similar. Neuroendocrine markers (chromogranin A, neuron-specific enolase) are useful in diagnosis of pheochromocytoma. Frequency of S- 100 protein positive sustentacular cells is high in benign pheochromocytomas and low in malignant pheochromocytoma (our results suggest that, S-100 immunostaining is a useful marker to predict malignant behavior in pheochromocytoma. Intensity of neuron-specific enolase may be similar in both benign and malignant pheochromocytoma). No significant correlation was observed between expression of chromogranin A and neuronspecific enolase in pheochromocytoma and survival. The features of histopathological changes are the most important basis to make diagnosis for neuroblastomas group. Immunohistochemical staining can verify it further and play an important role in its differential diagnosis. |
