Friday Quiz # 13 Answer | Figure 1

CincyKidsRad

Cincinnati Children's Radiology

Friday Quiz # 13 Answer

Sagittal (image 1) and axial (image 2) CT of the thoracic spine show an abnormal appearance of the occiput, thoracic vertebral bodies, and visible ribs. The skull base is thickened and sclerotic with a ground-glass matrix. Vertebral bodies are enlarged with a ground-glass matrix. Pathologic fractures with vertebral plana are present at multiple levels. The findings are typical of polyostotic fibrous dysplasia. Other entities that can cause multiple lucent lesions in the skull include metastatic neuroblastoma or Langerhans' cell histiocytosis. Lesions that can cause expansion of the skull include metastatic neuroblastoma, beta thalassemia, and sickle cell disease.

Similar Cases

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.

Hand radiograph shows multiple lucent lesions in the majority of metacarpals and bones of the fingers. The lesions are all lucent, mildly expansile, and contain a ground glass matrix typical of enchondromas. Patients with multiple enchondromas are said to have Ollier disease. Patients with Ollier disease have a 25% risk of developing chondrosarcoma by age 40.

Coronal image from an F18-FDG PET in a patient with Langerhans cell histiocytosis (LCH) shows uptake within the collapsed vertebral body (arrow). LCH is the most common cause of vertebra plana in a child. LCH is an oncologic disorder causing abnormal proliferation of histiocytes. In children, other causes of vertebra plana include leukemia, osteomyelitis, osteoporosis (usually related to medications such as long-term steroid therapy), and metastatic disease.

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. Fibrous dysplasia usually presents in the second and third decades of life, with craniofacial involvement accounting for up to a quarter of monostotic cases.