Imaging Characteristics of Occipital Bone Osteoblastoma

Abstract

Osteoblastoma is a rare benign tumor of the calvarium. We present the case of a 20-year-old female with occipital osteoblastoma and discussion of imaging modalities of calvarial osteoblastoma. To our knowledge, this is the ninth reported case of occipital osteoblastoma. Imaging characterization of osteoblastoma may vary. Plain radiograph, CT, MRI, and CT angiography establish osteoblastoma characterization and vascular supply prior to surgical resection.

Clinical characteristics and diagnostic imaging of cranial osteoblastoma

“…While only rarely infiltrative, osteoblastoma may grow to such large sizes as to compress or depress the brain parenchyma [10,26,55], often adhering to surrounding structures and underlying dura. Although the dura is usually normal in appearance, it may also be thinned [52].…”

“…Soft tissue density is sometimes present in a portion of the lesion [33,49,51,59,67,73]. Due to its vascularity, it is typically an enhancing lesion [10,18,20,22,31,35,54,55,66,74,75]; although, nonenhancing lesions have also been reported [15,32,34,44,76]. Despite many of the lesions having some or all of the characteristics described, there is great variety in its radiographic appearance, and it is often nonspecific [7].…”

“…Despite many of the lesions having some or all of the characteristics described, there is great variety in its radiographic appearance, and it is often nonspecific [7]. As such, there is much controversy about the capacity to diagnose osteoblastoma based solely on CT scan [45,55].…”

“…While CT scan provides important information regarding bony involvement, MRI provides critical information about adjacent brain parenchyma and helps narrow the differential; its ability to delineate tumor extension of the osteoblastic lesion, however, is variable [14,41,55]. Osteoblastoma and edema can have similar appearance on MRI, obscuring lesion borders [40].…”

“…Cases of dural enhancement without any gross reactive changes or contact with tumor have also been reported [41]. Most cranial osteoblastomas are hypointense to isointense on T1-weighted images [10,14,16,18,24,40,41,43,54,55,[57][58][59]62,66,71,75,77]. They have a variable presentation on T2-weighted images, with 19% having some degree of signal void, 29% having areas of hypointensity, 14% having areas of isointensity, and 38% having areas of hyperintensity.…”