mart-1-antigen and Pheochromocytoma

In daily routine pathology of the adrenal glands three tumor entities are important: adrenocortical tumors, adrenomedullary tumors and metastases. The differentiation of these three main tumor types can often be difficult structurally but immunostaining enables a definite diagnosis in nearly all cases. Adrenocortical tumors are positive for steroidogenic factor 1 and melan-A and always negative for chromogranin A whereas adrenomedullary tumors express chromogranin A but never keratin. A broad spectrum of antibodies is available for the identification of metastases and even the rare epithelioid angiosarcomas. For adrenocortical tumors, adenomas and carcinomas can be differentiated using three scoring systems and the Ki-67 index in adenomas should not exceed 3%. Using scoring systems and the Ki-67 index approximately 90% of cortical tumors can be differentiated into benign or malignant tumors. For pheochromocytomas two scoring systems are used for differentiating benign and malignant tumors but the results are less dependable.

Topics: Adrenal Cortex Neoplasms; Adrenal Gland Neoplasms; Adrenal Glands; Adrenal Medulla; Adrenocortical Adenoma; Biomarkers, Tumor; Chromogranin A; Humans; Keratins; MART-1 Antigen; Pheochromocytoma; Steroidogenic Factor 1

The aim of this study was to make immunohistochemical analyses with Inhibin alpha-subunit, Melan A and MNF116 (pan-Cytokeratin antibody) in pheochromocytomas, because immunohistochemistry is useful for the distinction between adrenal tumors.. We used 20 patients with pheochromocytomas submitted to laparoscopic (n=19) or classical (n=1) surgery and we have explored immuno-staining with Inhibin alpha-subunit, Melan A and MNF116 in these tumors. This can be helpful when we cannot make the distinction between adrenal tumors.. Pheochromocytomas did not stain with Inhibin alpha-subunit, Melan A and MNF116.. In our study, Inhibin alpha-subunit, Melan A and MNF116 were not sensitive for pheochromocytomas.

Topics: Adrenal Gland Neoplasms; Female; Humans; Inhibins; Keratins; Male; MART-1 Antigen; Metanephrine; Middle Aged; Normetanephrine; Pheochromocytoma

To investigate the potential diagnostic value of A103 and inhibin-alpha in adrenocortical tumors and to evaluate the applicability of tissue microarray/tissue chip in pathological studies using immunohistochemistry.. A tissue microarray/tissue chip was constructed to contain 179 formalin-fixed, paraffin-embedded adrenal tissue samples which include 3 normal adrenal cortex, 2 fetal adrenal cortex, 2 nodular adrenocortical hyperplasia samples, 72 adrenocortical adenomas, 39 adrenocortical carcinomas, 3 adrenal medulla, 13 metastatic carcinomas, 4 metastatic malignant melanomas and 44 pheochromocytomas. Additional 20 cases of normal adult adrenal gland were used as controls. Immunohistochemical markers, including A103, inhibin-alpha, calretinin and Ki-67 were used on the tissue array sections by EnVision immunohistochemical staining methods.. Positive staining of A103 was seen in all of the 23 (100%) adrenal cortex, 2 fetal adrenal cortex, 2 nodular adrenocortical hyperplasia samples, 60 of 66 (90.9%) adrenocortical adenomas samples, 35 of 37 (94.6%) adrenocortical carcinomas samples, 3 of 3 malignant melanomas, but in none of the adrenal medulla, pheochromocytomas or adrenal metastatic carcinoma samples. In all of the adrenal cortex, fetal adrenal cortex and nodular adrenocortical hyperplasia cases, inhibin-alpha immunoreactivity was limited to the zona reticularis and the innermost zona fasciculata. Fifty of the 66 (75.8%) adrenocortical adenomas, 28 of the 37 (75.7%) adrenocortical carcinomas were positive for inhibin-alpha. None of the adrenal medulla, pheochromocytoma, metastatic malignant melanoma or carcinoma samples showed a positive inhibin-alpha immunostain.. The tissue microarray/tissue chip technique provides a reliable method to investigate marker expression by offering a rapid, economic and accurate screening of tissue specimens on a large scale. The combined use of A103 and inhibin-alpha is valuable in distinguishing adrenocortical tumor from pheochromocytoma and other metastatic neoplasms.

Topics: Adrenal Cortex; Adrenal Cortex Neoplasms; Adrenocortical Adenoma; Adult; Antigens, Neoplasm; Female; Humans; Immunohistochemistry; Inhibins; Male; MART-1 Antigen; Neoplasm Proteins; Oligonucleotide Array Sequence Analysis; Pheochromocytoma

Morphologic distinction between adrenal cortical and medullary tumors can be difficult. Previous studies have shown inhibin, melan-A, and BCL-2 to be useful markers for adrenal cortical tumors. We have recently observed a high level of calretinin expression in normal adrenal cortex but not the medulla and therefore evaluated its diagnostic application for adrenal tumors in comparison with inhibin, melan-A, and BCL-2. C-kit is a transmembrane tyrosine kinase receptor. Immunodetection of c-kit expression has been recently used for tumor diagnosis, and c-kit-positive tumors can potentially benefit from kit kinase inhibitor treatment. Although c-kit expression was reported in adrenal medulla and pheochromocytoma, it has not been evaluated in adrenal cortical tumors. In this study, 28 adrenal cortical tumors (12 carcinomas, 16 adenomas), 20 pheochromocytomas, and 20 extraadrenal paragangliomas were evaluated for calretinin, inhibin, melan-A, BCL-2, and c-kit expression by standard immunohistochemical assays on paraffin sections. The percentage of immunoreactivity in adrenal cortical tumors was as follows: calretinin, 96%; melan-A, 89%; inhibin, 92%; BCL-2, 20%; and c-kit, 5%. Normal adrenal medulla did not stain for c-kit but was positive for BCL-2. Eighty-six percent of pheochromocytomas stained for BCL-2 and none for calretinin, with the exception of the ganglioneuromatous areas in composite pheochromocytomas (n = 5). Extraadrenal paragangliomas showed reactivity with calretinin in 25%, melan-A in 5%, inhibin in 16%, BCL-2 in 38%, and c-kit in 8% of the cases. Our results indicate that calretinin is the most sensitive among all the adrenal markers tested. Like melan-A and inhibin, calretinin is also a very specific marker in differentiating cortical from medullary adrenal tumors. In addition, calretinin can be used to confirm a composite pheochromocytoma. BCL-2 does not appear to be useful in differentiating adrenal cortical from medullary tumors. C-kit is not useful in the diagnosis of adrenal tumors, and kit kinase inhibitor might have a limited role in the treatment of adrenal tumors and paraganglioma because of the low frequency of c-kit expression in these tumors.

Topics: Adrenal Cortex Neoplasms; Adrenal Medulla; Antigens, Neoplasm; Biomarkers, Tumor; Calbindin 2; Diagnosis, Differential; Humans; Immunohistochemistry; Inhibins; MART-1 Antigen; Neoplasm Proteins; Pheochromocytoma; Proto-Oncogene Proteins c-bcl-2; Proto-Oncogene Proteins c-kit; S100 Calcium Binding Protein G