UCLA Radiological Sciences Proceedings

Primary synovial chondromatosis is an uncommon, benign synovial proliferative disorder rarely seen in children. The most commonly affected joint is the knee, followed by the hip. The symptoms of this condition are progressive and insidious and may include pain, joint stiffness, and swelling. Radiography is an appropriate first imaging modality that typically shows multiple calcified loose bodies within the affected joint space. Magnetic resonance imaging should then be performed to evaluate for the presence of noncalcified cartilaginous loose bodies and soft tissue involvement prior to surgical treatment that is necessary to prevent permanent joint damage. The recurrence of primary synovial chondromatosis is common, especially in cases of incomplete surgical excision. We report a case of primary synovial chondromatosis in a child. The diagnostic and the treatment considerations of the case are briefly discussed.

Overuse or structural bony abnormalities of the scapulothoracic “articulation” make it susceptible to chronic friction, which can lead to bursitis and soft tissue changes. Clinically, scapulothoracic bursitis is associated with pain, crepitus, and scapular snapping. On physical examination, a firm, large subscapular mass may be present, sometimes with rapid growth. Asymptomatic cases without scapular snapping can be clinically indistinguishable from soft tissue tumors of the chest wall. Characteristic imaging findings of scapulothoracic bursitis include a well-circumscribed cystic mass, internal debris, and intralesional hemorrhage. Recognition of these characteristic findings is essential to avoid misinterpretation and unnecessary treatments. Here, we describe a case of an incidentally discovered, asymptomatic, fluorodeoxyglucose (FDG)-avid subscapular mass with typical imaging features of scapulothoracic bursitis. Additional imaging and histopathologic examination of sampled tissue confirmed the diagnosis. To our knowledge, this incidental finding is the first documented case of FDG-avid scapulothoracic bursitis.

Fenestration of the internal carotid artery (ICA) is an extremely rare congenital abnormality thought to be secondary to incomplete segmental fusion of vessels at the early stages of their development. Fenestration is usually asymptomatic and often misdiagnosed as arterial dissection. Distinction between the two can be challenging on both magnetic resonance angiography and computed tomography angiography, and digital subtraction angiography must often be utilized for precise characterization of the abnormalities. Certain imaging features, namely the length of the involved arterial segment, the regularity of luminal contour, the symmetry of arterial limbs, and the absence/presence of fusiform dilatation of either limb, produced by noninvasive angiography have the potential to help distinguish between an ICA fenestration and dissection. We report a case of an asymptomatic, true fenestration of a short segment of ICA and discuss its imaging characteristics.