“…Although the etiology of EC transforming into malignancy is unclear, tobacco use, male gender, chronic irritation, trauma and recurrent infection are the triggering factors that have been suggested. Persistent chronic irritation due to chronic inflammation or repeated trauma cause the damage to the lining cells of cyst and the repeated damage and repair process finally could result in dysplastic changes and invasive carcinoma [3] , [9] , [11] . In a long-standing EC, the MT can occur suddenly with some abnormal changes in the cyst including; a firm mass replacing the cyst, increase in size, discharge, pain, ulceration and bleeding inside the cyst which do not response to conservative treatment [7] , [10] , [12] .…”