GENERALIZED METAPHYSEAL MODIFICATION WITH CONE-SHAPED EPIPHYSES FOLLOWING LONG-TERM ADMINISTRATION OF 13-CIS-RETINOIC ACID

We report on a 6-year-old girl with short stature which developed foll owing the administration of 13-cis-retinoic acid (a synthetic derivati ve of vitamin A or retinoid) for 40 months as adjunct chemotherapy for neuroblastoma. Radiographic examination suggested osteophyte formatio n in the cervical spine, which is the most common skeletal manifestati on of retinoid toxicity [10, 11]. In addition, severe metaphyseal cupp ing with a cone-shaped epiphysis primarily affecting rapidly growing l ong bones was found, which represented impaired enchondral ossificatio n. This epi-metaphyseal alteration, though unusually severe, was remin iscent of the premature epiphyseal closure which has been described as an adverse effect of 13-cis-retinoic acid [10-12]. Other minor skelet al changes included posterior scalloping of the vertebral bodies and i ncreased interpediculate distances, which were related to a widened sp inal canal found on CT. A literature search disclosed several primary skeletal dysplasias with superficial radiological similarities to thos e of the present patient. However, these entities showed significant c linical and radiological differences from our patient. Conclusion The precise cause of the generalized skeletal alteration in the present pa tient remained unknown, but it conceivably resulted from the administr ation of 13-cis-retinoid acid.