The Localization of Microadenoma with Sella Imaging Study and Inferior Petrosal Sinus Sampling in Cushing's Disease / 대한내분비학회지

ABSTRACT

Background: Inferior petrosal sinus sampling(IPSS) is known to be useful for the differential diagnosis of ACTH-dependent Cushings syndrome and for the preoperative lateralization of pituitary microadenoma. We tried to analyze the relative value of IPSS in localization of microadenoma as compared with sella imaging study including computerized tomogram(CT) or magnet resonance imaging(MRI) in Cushings disease. Methods: We reviewed the clinical records of 21 patients with Cushings disease who underwent IPSS and the radiologic study such as sella CT or sella MRI preoperatively followed by transsphenoidal microsurgery. By pathologic examination including immunohistochemistry and postoperative clinical and biochemical evaluation we confirmed the diagnosis of Cushings disease due to pituitary microadenoma in all 21 cases. Results: Sella CT or sella MRI detected microadenoma in 57.1% of cases( =12/21), while recently available dynamic MRI did so in 7 out of S cases. With IPSS the diagnosis of Cushings disease was possible in 90.5% of cases(= 19/21), but accurate lateralization of microadenoma was achieved in only 63.2% of cases( =12/19). IPSS precisely localized the pituitary microadenoma in 6 out of 9 cases whose lesion were not detected by the radiologic study. Of 7 cases in which IPSS failed to localize microadenoma, the radiologic study detected the lesion in 6 cases. Of 5 cases in which IPSS and the radiologic study showed a discrepancy in location of microadenoma, the radiologic study correctly localizaed the lesion in 4 cases and IPSS did so in one case. Conclusion: IPSS is not more reliable than sella imaging study for preoperative localization of microadenoma in Cushings disease. However it might have a complementary role, especially when sella imaging study failed to visualize the lesion.