Adrenal cortical neoplasms: a study of clinicopathological features related to epidermal growth factor receptor gene status

BACKGROUND: Adrenocortical carcinoma (ACC) is a rare but highly malignant neoplasm with limited treatment options. METHODS: In this study, the clinicopathological features of 22 ACCs and 22 adrenocortical adenomas (ACA) were analyzed, and the EGFR protein expression, EGFR gene mutation status and EGFR gene copy number alteration of all tumors were examined using immunohistochemistry, fluorescence in situ hybridization (FISH), and the Scorpion Amplification Refractory Mutation System (ARMS), respectively. RESULTS: EGFR protein expression was detected in 63.6% of the ACC samples, and EGFR FISH was positive in 50% of the ACC samples (all were high polysomy on chromosome 7). In contrast, 27.3% of the ACA samples demonstrated EGFR expression, and none of the ACA samples tested positive by FISH. There were significant differences between the ACC and ACA in terms of protein expression (P = 0.035) and gene copy number alterations (P < 0.001). CONCLUSIONS: EGFR protein expression and high polysomy on chromosome 7 are frequent abnormalities in ACC than in ACA. VIRTUAL SLIDES: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/2068470757103500.