POSSIBLE USE OF IMMUNOHISTOCHEMISTRY MARKERS IN THE DIFFERENTIAL DIAGNOSIS OF ADRENOCORTICAL TUMORS

Program: Abstracts - Orals, Featured Poster Presentations, and Posters
Session: MON 1-36-Adrenal Incidentaloma & Carcinoma
Clinical
Monday, June 17, 2013: 1:45 PM-3:45 PM
Expo Halls ABC (Moscone Center)

Poster Board MON-24
Sofia Pereira1, Tiago Morais1, Madalena Costa1, Mariana Pereira Monteiro2 and Duarte L Pignatelli*3
1Instituto Ciências Biomédicas Abel Salazar, Porto, Portugal, 2Instituto Ciências Biomédicas Abel Salazar, Matosinhos, Portugal, 3Hospital S Joao, Porto, Portugal
Malign adrenocortical tumors are rare and highly aggressive. Conversely benign tumors are more common and frequently found incidentally. The diagnosis of these tumors is based on the clinical evolution but histological characteristics have been the basis for prognostication. There have been much controversy about the use of molecular markers in the confirmation of malignancy but there has been significant progress recently.

The aim of the present study was to analyze the molecular profile of different adrenocortical tumors with the purpose of identifying useful sets of markers for the differential diagnosis and orientation of post-operative therapeutics.

We studied a set of adrenocortical tumors (n=31) consisting of non-functioning adenomas/incidentalomas (n=13), functioning adenomas with Cushing syndrome (n=7),and carcinomas (n=11); Normal adrenal glands (n=12) were used as controls. For each sample, the percentage of the stained area and the QIC score (Quantitative immunocitochemical score) by immunohistochemistry were quantified for StAR, IGF2, IGF1-R, p53, Mdm2, p21, p27, cyclin D1, Ki-67, β-catenin and E-cadherin, using a morphometric computerized analysis tool.

Of the studied markers, IGF2, p27, cyclin D1 and Ki-67 were those whose percentage of marked area and QIC score were significantly higher on carcinomas when compared with all the adenomas. Comparing the carcinomas with the functioning Cushing syndrome adenomas, we observed significant differences in the percentage of the stained area and QIC score for p27 and Ki-67, which were increased, and for StAR that was decreased in carcinomas (but nevertheless present).

 Comparing the carcinomas with incidentalomas, the marked area for IGF2, p27, cyclin D1 and Ki-67 was significantly higher on carcinomas. The p27 and the Ki-67 were the markers that showed the highest discriminative power for the differential diagnosis between carcinomas and adenomas, while the IGF2 only demonstrated to be useful for the differential diagnosis between carcinomas vs non-functioning adenomas and StAR  between carcinomas vs adenomas with Cushing syndrome.

            The use of the markers StAR, IGF2, p27 and Ki-67, and the quantification of its expression by computerized morphometric analysis could be an important auxiliary means on the differential diagnosis of adrenocortical tumors.

Nothing to Disclose: SP, TM, MC, MPM, DLP

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