抄録
We report a case of recurrence of an aneurysmal bone cyst (ABC) which developed in the right proximal ulna of a 9-year-old girl. Radiography revealed a radiolucent lesion with a bulging, thin cortex, septa, and a ground-glass appearance. Magnetic resonance imaging revealed that the tumor, measuring 73×30mm, was located in the proximal ulna near the physis, and contained septa and a fluid-fluid level. The tumor was subsequently diagnosed as an ABC by open biopsy, and was treated by surgical curettage and packing with artificial bone. However, the tumor recurred 4 months after surgery. First, the recurrent tumor was subjected to wide curettage, then absolute ethanol was injected into the cyst, followed by packing with artificial bone. The post-reoperative course was uneventful without recurrence. ABCs show a high rate of recurrence. Many arise near open physes or articular cartilage in skeletally immature patients. The risk of recurrence is highest in pediatric patients with juxtaphyseal lesions. In the present case, concern about possible damage to the physis and thin cortex discouraged us from curetting the tumor aggressively. Preservation of the physis remains a high priority of treatment, and adjuvant therapy, such as injection of absolute ethanol, application of liquid nitrogen, or argon laser cautery, should be combined with curettage whenever possible.
