Giant ischial osteochondroma causing ischiofemoral impingement and sciatic nerve compression in a pediatric patient with Albright's hereditary osteodystrophy.

An 8-year-old female with Albright's hereditary osteodystrophy (AHO) presented with severe right buttock pain, difficulty walking, and a palpable mass in the right ischiofemoral region. Imaging studies demonstrated a large, ossified lesion compressing the sciatic nerve. Surgical resection of the mass resulted in complete resolution of symptoms and restoration of normal gait and function. AHO is a rare genetic disorder caused by mutations in the GNAS1 gene and is characterized by musculoskeletal abnormalities, including a predisposition to subcutaneous ossifications. While osteochondromas are typically asymptomatic, they can cause significant clinical symptoms when they enlarge or impinge on adjacent neurovascular structures. This case illustrates the rare co-occurrence of AHO and a symptomatic giant osteochondroma, underscoring the importance of early recognition and surgical intervention to prevent functional impairment due to neurovascular compression.