Spectrum of lytic lesions of the skull: a pictorial essay

Lytic lesions of the skull include a wide range of diseases, ranging from benign conditions such as arachnoid granulations or vascular lacunae, to aggressive malignant lesions such as lymphomas or metastases. An early and correct characterisation of the nature of the lesion is, therefore, crucial, in order to achieve a fast and appropriate treatment option. In this review, we present the radiological appearance of the most frequent lytic lesions of the skull, describing findings from different imaging modalities (plain X-rays, CT and MRI), with particular attention to diagnostic clues and differential diagnoses. TEACHING POINTS: • Osteolytic skull lesions may be challenging to diagnose. • Association of different imaging techniques may aid image interpretation. • Clinical information and extensive knowledge of possible differential diagnoses is essential. • Some osteolytic tumours, although benign, may present as locally aggressive lesions. • Malignant lesions require accurate staging, followed by variable treatment approaches.