The fourth Edition of the World Health Organization’s Classification of Tumours of Endocrine Organs from 2017 introduced some novelties based primarily on genetic research, compared to the previous edition from 2004. The most common primary tumors of the adrenal cortex are adenomas, and of the adrenal medulla are pheochromocytomas. As such, these tumors have their specificities in pathohistological diagnosis, by which they differentiate from tumors of other localizations. In the daily work of the pathologist dealing with the diagnosis of the tumor of the adrenal gland, differential diagnostic problems can occur, where biological behavior of the tumor cannot be predicted based on its morphological appearance; this primarily refers to cortical neoplasms and phaeochromocytomas. Scoring systems are used in these cases, Weiss and Lin-Weiss-Bisceglia criteria for cortical neoplasms, and PASS criteria for pheochromocytomas, where by recognizing the suggested morphological parameters, value or score is obtained which predicts the biological behavior of the tumor, i.e. differentiates benign from malignant neoplasms. The accepted algorithm of diagnostics of adrenocortical neoplasms also includes immunohistochemical staining for ki-67, which potentially can differentiate adrenocortical adenoma from carcinoma. Despite the introduction of these scoring systems, the only safe indicator of malignancy is still distant metastasis.