Clinical and radiologic features of patients with CLTC::SYK fusions. (A) Radiologic and clinical images of the tumor in case 2. The tumor of the right lower arm was present at birth and had rapidly increased in size over time. On physical examination, the tumor was firm, adherent to the underlying musculature, and separate from the skin. The overlying skin exhibited telangiectatic changes, possibly because of fast growth of the tumor. Ultrasound revealed a well-demarcated, hypoechoic, vascularized lesion. MRI demonstrated that the tumor was closely related to the underlying extensor carpi radialis brevis muscle. A biopsy was taken 2 months after birth and a diagnosis of JXG was made. The patient was managed by active monitoring and the tumor gradually decreased in size and consistency. At a follow-up visit 1.6 years after diagnosis, the tumor was no longer recognizable. (B) Clinical and ultrasound images of the tumor in case 10. This infant presented 4 weeks after birth with a thoracal mass that had been noted by the parents for 1 day. On physical examination, the mass was firm-elastic, nontender, adherent to the underlying tissue, and separate from the skin. The patient had no other symptoms; therefore, a diagnosis of self-limiting sternal tumor of childhood37 was assumed, and the patient was managed by active monitoring. Follow-up ultrasound evaluations revealed slow progression of the parasternal lesion, which extended between the second and third ribs to the parietal pleura. Therefore, subtotal surgical resection was eventually performed at 6.5 months after presentation; pathological analysis resulted in a diagnosis of JXG. At 2 months after surgery, the parasternal lesion was not detectable using ultrasound and the child was in clinical remission.
