Usefulness of transcription factors Ad4BP/SF-1 and DAX-1 as immunohistologic markers for diagnosis of advanced adrenocortical carcinoma

Background: We examined the expressions of Ad4BP/SF-1 and DAX-1 in primary and metastatic lesions of advanced adrenocortical carcinoma with normal hormonal findings by immunohistochemistry and discussed their usefulness as immunohistochemical markers for diagnosis.

Patients and methods: Four patients (average age 54.3 +/- 3.9) with retroperitoneal and metastatic tumors were enrolled in this study. All patients had normal hormonal findings. Ad4BP/SF-1 and DAX-1 underwent immunohistochemical study using needle biopsy specimens from the retroperitoneal tumor or metastatic tumor of these patients to diagnose primary adrenocortical carcinoma.

Results: Immunoreactivity for Ad4BP/SF-1 and DAX-1 indicated that it was localized exclusively in the nuclei. Ad4BP/SF-1 immunoreactivity was observed in the carcinoma cells of 2 patients, but not in the others, whereas DAX-1 immunoreactivity was observed in the carcinoma cells of all 4 patients.

Conclusion: The expressions of Ad4BP/SF-1 and DAX-1 are considered essential to maintain the biological characteristics of adrenocortical cells even without abnormal hormonal findings or even after malignant transformation and metastasis. These markers are useful to distinguish other retroperitoneal tumors, especially in patients with bulky tumors, and to diagnose the metastatic site of origin as adrenocortical carcinoma in patients clinically presenting with widespread metastasis.