Clinical Value Of CT Features In Differential Diagnosis Of Adrenal Occult Pheochromocytoma And Cortical Adenoma

Objective: Investigating the differences of CT features of adrenal hidden pheochromocytoma and incidental adrenal cortical adenoma,so as to guide the differential diagnosis and clinical treatment of hidden pheochromocytoma.Methods: A total of 177 patients with incidental adrenal tumors admitted to the First Affiliated Hospital of China Medical University from January 2010 to January 2020 were collected for retrospective analysis,including 56 cases of hidden pheochromocytoma,32 cases of cortisol adenoma,44 cases of aldosterone adenoma,45 cases of non-functional adenoma.Comparing the general clinical data such as age,gender,clinical manifestation,preoperative diagnosis,and CT features including location,diameter,CT value of both plain and enhancement scan.Trying to calculate the optimal cut-off value to differentiate adrenal hidden pheochromocytoma from incidental adrenal cortical adenoma.Results: There was statistically significant difference between the location of hidden pheochromocytoma and non-functional adenoma.Among 56 cases of hidden pheochromocytoma,40 cases underwent laparoscopic surgery and 16 cases underwent open surgery.Blood pressure was stable in 9 cases,accounting for 16% of hidden pheochromocytoma in this study;other 47 cases had different degree of blood pressure fluctuation(140/90 mm Hg～230/110 mm Hg),accounting for 84%.Diameter of tumors,plain scan CT value and both arterial and delayed periods enhancement CT value of hidden pheochromocytoma group were significantly greater than all three adrenal adenoma groups.If the tumor diameter ≥2.95 cm was used to diagnose the hidden pheochromocytoma from adrenal cortical adenoma,AUC was 0.872,sensitivity was87.5% and specificity was 76.0%.If the CT value of plain scan ≥ 24.5Hu,the AUC,sensitivity and specificity were 0.929,94.0% and 82.5% respectively.If the arterial enhanced CT value ≥89.5HU,AUC was 0.886,sensitivity was 72.7%,and specificity was 90.6%.If the enhanced CT value in the delay period was ≥82.5HU,the AUC,sensitivity and specificity were 0.937,84.6% and 95.3% respectively.If combined above all four indicators,the AUC was 0.981,the threshold was ≥0.118,the sensitivity was100%,and the specificity was 90.6%.Conclusion: The value of 24.5HU in plain scan,89.5HU in arterial enhanced CT and82.5HU in delayed enhanced CT with tumor diameter of 2.95 cm is useful for the differential diagnosis of adrenal hidden pheochromocytoma.