We report two cases of solitary cortical tubers not associated with tuberous sclerosis and having an appearance simulating neoplasm in two patients presenting with seizures. CT showed solitary, hyperdense frontal lobe lesions in both patients. MR revealed a lesion hyperintense on both T1- and T2-weighted images in one patient and a heterogeneous mass with a target appearance in the other. Histologically, the lesions were consistent with cortical tubers.