Definitive diagnosis requires cytologic and histopathologic evaluations. A benign nevus is read as (or understood as) having no cytologic or architectural atypia. Small degrees of cytologic variation can be observed and subsequent subtypes have been described. These demonstrate various degrees of cytologic atypia, including hyperchromasia, pleomorphism, prominent nucleoli. If the nodule is malignant or has indeterminate cytologic features, it may require surgery. Cytologic imprints may reveal schizont-laden endothelial cells. In this sense, it is termed a "cytologic smear". Usually, cytologic atypia is of more important clinical concern than architectural atypia. Helpful features for diagnosis are bland cytologic features and adjacent tubular and spindle cell components.