Buschke-Ollendorff Syndrome: A Rare Cause of Unilateral Genu Valgum.

Buschke-Ollendorff syndrome is a rare, often benign, autosomal dominant skin disorder. This syndrome commonly presents with non-tender connective tissue nevi and sclerotic bony lesions. Characteristic skeletal findings such as melorheostosis and hyperostosis are usually present. Most cases are detected incidentally. Skin lesions appear first and become less noticeable with age. Bone lesions occur in the later decades of life. Another rarely associated symptom, melorheostosis, is manifested by the appearance of wax running through the cortex of the bone. Plain radiographs usually show cortical hyperostosis. This study aims to present a case report of Buschke-Ollendorff syndrome from an orthopedic aspect and emphasize the importance of the disease since it can be easily assessed as a bone tumor. Second, to the best of our knowledge, this is the first case presented with a unilateral genu valgum deformity with a long-term follow-up in the relevant literature.