Cerebral cavernous malformations: Typical and atypical imaging characteristics.

Cavernous malformations (CMs) are benign vascular malformations that maybe seen anywhere in the central nervous system. They are dynamic lesions, growing or shrinking over time and only rarely remaining stable. Size varies from a few millimeters to a few centimeters. CMs can be sporadic or familial, and while most of them are congenital, de novo and acquired lesions may also be seen. Etiology is still unknown. A genetic molecular mechanism has been proposed since a cerebral cavernous malformation gene loss of function was found in both familial and sporadic lesions. Additionally, recent studies suggest that formation of CMs in humans may be associated with a distinctive bacterial gut composition (microbioma). Imaging is fairly typical but may vary according to age, location, and etiology. Follow-up is not well established because CMs patients have a highly unpredictable clinical course. Angiogenic and inflammatory mechanisms have been implicated in disease activity, as well as lesional hyperpermeability and iron deposition. Imaging and serum biomarkers of these mechanisms are under current investigation. Treatment options, including surgery or radiosurgery, are not well defined and are dependent upon multiple factors, including clinical presentation, lesion location, number of hemorrhagic events, and medical comorbidities. Our purpose is to review the imaging features of CMs based on their size, location, and etiology, as well as their differential diagnosis and best imaging approach. New insights in etiology will be briefly considered. Follow-up strategies, including serum and imaging biomarkers, and treatment options will also be discussed.

Imaging of pediatric nasal masses: A review.

Several conditions may present as nasal masses in pediatric age, including congenital and developmental disorders, inflammatory and infectious conditions, neoplastic and neoplastic-like lesions, and other miscellaneous disorders. A confident presurgical diagnosis can be challenging and imaging is often key in the management of these lesions. We provide a pictorial review of pediatric nasal masses and discuss a location-based approach to the diagnosis of these lesions on imaging studies. Acquaintance with the most common pathologies and awareness for its characteristic imaging features can aid the physician in the differential diagnosis. Location and extension of the lesion can be particularly helpful. Midline masses raise suspicion for developmental nasal midline lesions, including frontoethmoidal cephalocele, dermoid/epidermoid cyst, and neuroglial heterotopia. In case of trauma, nasal septum hematoma/abscess should be considered. Developmental or odontogenic cystic lesions and osseous neoplasms and neoplasm-like lesions can originate from the maxilla and palate. Although most nasal tumors show overlapping imaging characteristics, some have suggestive features, such as nasopharyngeal angiofibroma and esthesioneuroblastoma. Malignant tumors tend to be locally aggressive, demonstrating invasive features, bony erosion, intermediate signal on T2-weighted images, and restricted diffusion on diffusion-weighted imaging. In certain cases, a definite diagnosis can only be made histologically. Nonetheless, detailed characterization of the lesion is crucial prior to invasive procedures in order to avoid complications.