Radiological review of skull lesions

Abstract

Calvarial lesions are often asymptomatic and are usually discovered incidentally during computed tomography or magnetic resonance imaging of the brain. Calvarial lesions can be benign or malignant. Although the majority of skull lesions are benign, it is important to be familiar with their imaging characteristics and to recognise those with malignant features where more aggressive management is needed. Clinical information such as the age of the patient, as well as the patient’s history is fundamental in making the correct diagnosis. In this article, we will review the imaging features of both common and uncommon calvarial lesions, as well as mimics of these lesions found in clinical practice.Teaching Points • Skull lesions are usually discovered incidentally; they can be benign or malignant. • Metastases are the most frequent cause of skull lesions. • Metastatic lesions are most commonly due to breast cancer in adults and neuroblastoma in children. • Multiple myeloma presents as the classic “punched out” lytic lesions on radiographs. • Eosinophilic granuloma is an osteolytic lesion with bevelled edges.

Imaging of skull vault tumors in adults

“…Nevertheless, it is very polymorphic on imaging, and bone invasion can take different forms instead of the specific hyperostosis: well-defined lytic (simulating metastases or plasmacytoma), permeative/moth eaten (simulating lymphoma or small-round cell metastasis), or even aggressive periosteal reaction (eventually misleading to the suspicion of osteosarcoma or metastasis) ( Fig. 12) [18,43,44].…”

Fibrous Dysplasia, Paget's Disease of Bone, and Other Uncommon Sclerotic Bone Lesions of the Craniofacial Bones

“…The presence of remnants of normal bone fatty marrow is an important discriminator with a malignant osseous process that does not exhibit normal yellow marrow. 24 The T2 signal is high in this phase, and enhancement is present, owing to its hypervascularity. 27 Due to the hypervascular nature of PD, scintigraphy shows increased uptake even before lytic areas develop on CT. 18 In the second mixed phase, skull radiography may exhibit the characteristic cotton wool appearance.…”

“…Craniofacial involvement causes increased head size and possible cranial nerve compression. 24 Deafness is reported in up to 85% of patients with temporal bone involvement. 25 Transformation to osteosarcoma (1%), chondrosarcoma, or giant cell tumor is a well-known, albeit rare, complication.…”

Osseous Manifestations of Primary Hyperparathyroidism: Imaging Findings

“…Salt-and-pepper skull refers to diffuse, lytic foci interspersed between regular bone in the calvarium giving a granular skull appearance that occurs as a result of HPT [32]. In PHPT, the pathogenesis involves trabecular bone resorption that leads to decreased differentiation of the diploic space bone marrow and the inner and outer tables of the calvarium [5].…”

“…e expanded differential diagnosis of skull demineralization includes osteoporosis associated with aging and less commonly anemias such as sickle cell and thalassemia, HPT, metastatic bone disease, multiple myeloma, and the lytic phase of Paget disease [35]. In differentiating the calvarium salt-and-pepper International Journal of Endocrinology skull of PHPT from other lesions of the calvarium, further confirmation with patient characteristics, clinical history, laboratory analysis, and imaging in combination is essential [32].…”