MKI67 and adrenal cortex carcinoma: To facilitate and standardize the diagnosis of ACC, several multiparametric scoring systems have been developed based on combined histopathological features, such as the Weiss score and the Helsinki score.4 The Weiss score considers nine histopathologic parameters and remains one of the most used scoring systems in clinical practice to classify conventional ACC in adults.5 A more recently developed score, the Helsinki score, focuses on a combination of the Ki67 proliferation index, mitotic rate, and the presence of necrosis.