Tehran University of Medical Sciences Acta Medica Iranica 0044-6025 53 1 2015 01 15 69 73 EN Hosein Dalili Department of Pediatrics, Breast Feeding Research Center, Tehran University of Medical Sciences, Tehran, Iran. Zahra Dalili Kajan Department of Maxillofacial Radiology, School of Dentistry, Guilan University of Medical Sciences, Guilan, Iran. 2015 10 11 This case report presents an eight-year-old girl having periauricular swelling and severe pain during mouth opening on the right-side temporomandibular joint (TMJ). CBCT showed extensive destruction of the base of the skull and the roof of the glenoid fossa on the right side. The findings based on CT and MRI images with and without contrast are discussed herein. This report highlights a skull base eosinophilic granuloma that mimics TMJ disorder and the importance of proper evaluation of CBCT images to make an early diagnosis. https://acta.tums.ac.ir/index.php/acta/article/view/4933 https://acta.tums.ac.ir/index.php/acta/article/download/4933/4301