Diagnosis of a sublingual epidermoid cyst using contrast medium radiography: a case report R. BenolieI, J. Kau and D. Nitzan Hadassah Faculty of Dental Medicine, Hebrew University, Jerusalem, Israel Received 7 June 1989 and in final form 21 September 1989 A case of a sublingual epidermoid cyst is presented. The of contrast radiography in diagnosis, localization and surgical treatment planning are exemplified. Keywords: Epidermal cyst; mouth floor; contrast media; diagnosis, oral Case report A 28-year-old Caucasian female was referred from the ENT department for investigation of a painless, growing swelling in the left submandibular area first noticed about 5 years before. It had been symptomless until one and a half months previously when pain and discomfort had forced the patient to seek help. There were no aggravating factors and the patient felt well. On examination she was apyrexic with a large swelling in the left submandibular area (Figure 1) which on palpation, was freely mobile, not tender and firm. No overlying skin changes were noted and there was no regional lymphadenopathy. Intra-orally, there was no sublingual swelling and saliva flowed freely from both Wharton's ducts. A grossly carious mandibular left first molar irrelevant to her symptoms, was extracted. An initial' differential diagnosis was made of neoplastic Figure 1 Profile of patient showing submandibular swelling © 1990 IADMFR 0250--832 x 90/010037-m or inflammatory salivary gland disease, ranula or dermoid cyst. Sialography was performed using an medium (Pantopaque, Lafayette Pharmacal Division, Alcan Labs. Inc., Puerto Rico, USA). The acinar pattern appeared normal apart from a filling defect anterosuperiorly (Figure 2, arrow). There was marked dilatation of the main duct. The position of the gland also seemed abnormal and an extraglandular space- occupying lesion was suspected. A radiograph taken 90 minutes later showed retained contrast medium but the dilatation of the main duct had disappeared. This was thought to be due to overfilling ,?f the gl.and. the point where the extraglandular lesion was impmgmg on the duct causing a partial obstruction; as the gland emptied: the pressure subsided and the dilatation resolved. In view of these sialographic findings, the possibility of a dermoid cyst was reconsidered and aspiration of the lesion through the floor of the mouth attempted. Straw-coloured fluid (5 ml), suggestive of an epider- moid cyst', was obtained and, through the same Figure 2 Sialogram showing duct dilatation and filling defect (arrowed) Dentomaxillofac. Radiol., 1990, Vol. 19, February 37