The Use of Immunohistochemical Expression of SF-1 and EMA in Distinguishing Adrenocortical Tumors from Renal Neoplasms.
Miriam L Enriquez, Priti Lal, Amy Ziober, Liping Wang, John E Tomaszewski, Zhanyong Bing. Hospital of the University of Pennsylvania, Philadelphia
Background: Steroidogenic factor -1 (SF-1) is an orphan member of the nuclear hormone receptor superfamily, and is considered to play an important role in the differentiation of steroidogenic tissues. Previous studies have shown SF-1 to be specifically expressed in normal adrenal gland, adrenal adenomas and carcinomas, and have also shown negative immunoreactivity in renal cell carcinomas (type not specified). In this study, we further examined the expression pattern of SF-1 in adrenal tumors by immunohistochemical staining using tissue microarrays of adrenal glands and adrenal cortical tumors. Furthermore, in order to evaluate the potential of SF-1 in distinguishing adrenocortical tumors from renal neoplasms, we compared the expression of SF-1 and EMA in the adrenal cortical TMAs versus a renal tumor TMA.
Design: The adrenal tissue microarrays consisted of 19 cases of normal adrenal cortex, 22 cases of adrenal adenoma, and 20 cases of adrenocortical carcinoma. The renal tissue microarray consisted of 20 cases of each of following types of renal cell carcinoma: clear cell, papillary, and chromophobe. 20 cases of oncocytoma were also included. Immunohistochemistry for SF-1 and EMA was performed on the adrenal and renal TMAs. Nuclear staining for SF-1 in >10% of cells was considered positive, and intensity of staining was graded (1=weak, 2=moderate, 3=strong).
Results: SF-1 showed positive staining in all cases (100%) of normal adrenal cortex and adrenal adenoma, and in 18/20 (90%) cases of adrenocortical carcinoma. In renal tumors, SF-1 showed negative staining in all cases (100%) of oncocytoma, papillary and chromophobe renal cell carcinoma. 17/20 (85%) of clear cell renal cell carcinomas were negative for SF-1, while the three positive cases showed only weak staining in 10% of tumor cells.
EMA stained positively in 85%, 95%, 100% and 95% of clear cell, papillary, chromophobe renal cell carcinomas, and oncocytomas, respectively. EMA was completely negative in the adrenal TMAs.
Conclusions: SF-1 is a sensitive and specific marker for tumors of adrenal cortical origin. SF-1 and EMA can be used to differentiate adrenal tumors from renal tumors in difficult cases.
Tuesday, March 1, 2011 1:00 PM
Poster Session IV # 45, Tuesday Afternoon