Tehran University Medical Journal

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Different opinions exit in histological typing of bone cysts. Epidermoid cysts are very rare as the small numbers of published cases indicate. They arises following preceding trauma exclusively in distal phalanges and skull. The roentgenogram shows a round osteolytic resion with no trabecular pattern. We observed 2 cases of epidermoid cyst of finger in Imam Khomeini hospital central path department the patients were young workers complaining from local pain several months after trauma. Bone curettage was performed.

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Background: Simple bone cyst is a common benign lesion in the proximal humerus, especially in prepubertal children. Up to 75 percent of patients with the bone cyst have a pathologic fracture and the most significant complication is recurrent pathologic fracture. Since the process of spontaneous healing of these fractures is rare, treatment is required. Ideal treatment for simple bone cyst should stabilize pathologic fractures, assist healing and provide a quick return to normal activity with reduced complication and recurrence.
Methods: In this descriptive case series study, 24 patients with simple bone cysts of the humerus were selected for retrograde flexible intramedullary nailing from the lateral cortex of the distal humerus, since 2000 to 2005 at Imam Khomeini Hospital, Tehran. The mean age of the patients was 14.4 years, ranging from 6-39 years. Results were evaluated by plain radiography using the classification system of Capanna et al.
Results: The mean duration of follow up for 23 of the patients was 31 (9-51) months. One patient with short-term of follow-up was excluded. Of these patients, 91.3% were healed either completely (65.2%) or with residual minor defect (26.1%). Only one cyst (4.3%) persisted with no response to treatment and one patient (4.3%) had a recurrence of the cyst. However, there was no instance of recurrent pathologic fracture among these patients.
Conclusion: This study shows that flexible intramedullary nailing is an effective treatment for humeral simple bone cysts that reduces the chance of complication, recurrence of cyst or pathologic fracture. This technique provides sufficient stability for quick return to normal activity.