Adrenal neoplazmlarda patolojik özellikler, Ki-67 proliferasyon indeksi ve Melan-A ekspresyonu

Aim: Differential diagnosis of adrenocortical neoplasms and pheochromocytoma may occasionally be very difficult. Although recently developed molecular techniques are encouraging, histopathologic features and immunohistochemical markers are still the mainstay of diagnosis. The aim of this study is to re-evaluate the clinicopathologic features of our cases diagnosed as adrenocortical adenoma/carcinoma and pheochromocytoma. Material and Methods: Sixteen cases of adrenocortical neoplasm and 7 cases of pheochromocytoma, 3 of which were bilateral, diagnosed between 1995 and 2010 at Dokuz Eylul University Pathology Department were reviewed. The immunohistochemical staining of Ki-67 and melan-A were examined. Results: The mean age of the adrenocortical neoplasm cases was 45 years (range, 25-60). Fifteen of 16 adrenocortical neoplasms were cortical adenoma and 1 was cortical carcinoma. The mean Ki-67 proliferation index in the cortical adenoma cases was 1.7% (range, 0.2-6.0%). Four of the 15 adenoma cases (27%) were melan-A positive. In one cortical carcinoma case, the Ki-67 proliferation index was 20% and melan-A was negative. The mean age of the pheochromocytoma cases was 46 years (range, 28-63). Four pheochromocytoma cases were benign, whereas 3 cases, 2 of which were bilateral, had histopathologic features suggesting malignant behavior. The mean Ki-67 proliferation index of 10 pheochromocytomas from 7 cases was 3.3% (range, 0.2-20.0%), and none of these cases showed melan-A immunoreactivity. Conclusion: Although the number of patients is limited in this study, our findings suggest that Ki-67 immunohistochemical stain can be used in routine practice to determine tumor biology in adrenal neoplasms, and melan-A positivity may favor cortical origin in differential diagnosis of adrenocortical tumors and pheochromocytoma.