CincyKidsRad

Cincinnati Children's Radiology

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### 2024 Friday Quiz 23 Answer

Coronal CT (Image 1) and 3D reformatted CT (Image 2) show a bony mass (arrow) arising from the left parietal bone. The mass features a ground-glass matrix and deforms the skull's surface, characteristic of fibrous dysplasia. Differential diagnosis for a skull bony lesion includes calcified cephalohematoma and bone metastases, such as those from neuroblastoma. Calcified cephalohematomas typically lack a ground-glass matrix and instead have a calcified rim with a crenulated core. Neuroblastoma metastases are more spiculated. Fibrous dysplasia usually presents in the second and third decades of life, with craniofacial involvement accounting for up to a quarter of monostotic cases.

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##### More about this case

Resolved Common presentation

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##### Similar cases

Axial contrast-enhanced CT of the abdomen (image 1) shows the large retroperitoneal mass (arrow) uplifting the abdominal aorta (arrowhead). There are diffuse bone metastases with an abnormal appearance of the vertebral bodies on the sagittal CT of the spine (image 2). MIBG scan (image 3) shows bone metastases involving the calvarium, humeri, ribs, spine, pelvis, and femurs. The imaging findings are consistent with neuroblastoma. Neuroblastoma most commonly arises from the adrenal glands. It displaces and uplifts vessels. Neuroblastoma most commonly metastasizes to bone, bone marrow, and the liver.

A frontal skull radiograph exhibits a bony mass (arrow) arising from the outer table of the skull with a ground-glass matrix. What is your diagnosis for this finding?

Anterior projection from an MIBG scan shows diffuse skeletal metastases and a large intra-abdominal neuroblastoma. The bone metastases are most pronounced in the skull. Neuroblastoma is the most common extracranial solid malignancy of childhood. It most commonly metastasizes as two bones. Other entities that can cause diffuse thickening of the calvarium include thalassemia, sickle cell disease, and certain medications. #FridayQuizDay #FridayQuiz

Coronal CT image in a 3 month old with swelling since birth shows an evolving cephalohematoma in the left parietal bone (red arrow). This occurs from bleeding below the periosteum, so a cephalohematoma will be confined by the sutures. Occasionally as it evolves, it may mimic a more aggressive, lytic skull lesion, such as in this case, but it eventually incorporates into the skull. #NeuroWednesday

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