Unusual Onset of Intraosseous Epidermoid Cyst in Distal Phalanx

초록

Purpose : An intraosseous epidermoid cyst is a rare benign cystic lesion. It is thought to result from congenital factors or trauma. An osteolytic lesion with a sclerotic margin is a radiological feature which is shared with other diseases. Therefore, it is important to differentiate an intraosseous epidermal cyst with other tumors at distal phalanx. We would like to share experience of intraosseous epidermoid cyst in distal phalanx of ring finger. Methods : A 15-year-old male with a painful mass on the ring finger distal phalanx was presented after history of trauma. Based on X-ray, we observed radiolucent lesion which causes cortical thinning on the site. For the treatment and diagnosis, removal of intraosseous lesion and subsequent bone graft were planned. A fish mouth incision was performed on the fingertip and opened the thinned cortex. We removed the creamy material and performed wide curettage. On dorsum of wrist, transverse incision made radial side to Lister’s tubercle on ipsilateral radius. The harvested cancellous bone of the radius was grafted to the defect of distal phalanx. We didn`t perform bone fixation. Results : Intraosseous epidermoid cyst was confirmed with permanent biopsy. Grafted bone was well survived and well healed. There was no donor site problem. For 12 months, there was no evidence of recurrence. Conclusions : Many types of intraosseous tumors could be on the phalange such as enchondroma, intraosseous ganglion cyst, intraosseous lipoma, etc. But, intraosseous epidermoid cyst is very rare. In cyst lesion, it is necessary to make accurate diagnosis with radiologic imaging study and histological examination