Introduction: Multicentric carpotarsal osteolysis (MCTO) is a rare genetic skeletal disorder characterized by progressive osteolysis of the carpal and tarsal bones and frequent early misdiagnosis as juvenile idiopathic arthritis. Pathogenic variants in the MAFB gene are a recognized molecular cause. Early recognition is crucial, as conventional immunomodulatory therapies are typically ineffective, and emerging evidence suggests a potential role for denosumab in disease control. Case presentation: We report a 13-year-old girl, one of twins born to healthy nonconsanguineous parents, who developed bilateral wrist swelling with carpal involvement at approximately 3 years of age. She was initially treated as juvenile idiopathic arthritis with methotrexate and other immunomodulatory agents without clinical improvement. Progressive osteolysis subsequently led to marked destruction and loss of the wrist and carpal bones, and she was clinically diagnosed with multicentric carpotarsal osteolysis. Genetic testing confirmed a pathogenic MAFB gene mutation consistent with the diagnosis. She currently presents with bilateral knee pain on movement, tenderness, and joint effusions, with progressive functional limitation. Her parents express significant concern regarding potential loss of ambulation. She is presently receiving bisphosphonate therapy . Recent case reports describe disease stabilization with denosumab in genetically confirmed MCTO, underscoringthe importance of molecular diagnosis for therapeutic decision-making. Conclusion: This case highlights the progressive nature of MCTO, its poor response to immunosuppressive therapy , and the importance of genetic confirmation. Given ongoing functional decline despite bisphosphonate therapy , consideration of denosumab may represent a potential therapeutic option.