en Surgery Surgery گزارش مورد Case report A rare case of squamous cell carcinoma ex pleomorphic adenoma in maxillary sinus is presented. The patient is a 50-year-old woman presenting with a slow-progressive swelling in left side of her face that she has noticed 2 years earlier. The lesion was not painful and caused asymmetry and mild exophthalmos. Microscopic examination revealed that the tumor was composed of two components partly of a pleomorphic adenoma and partly of a squamous cell carcinoma. Immunohistochemical examination for Ki-67 and SMA and mucicarmin staining were also done and confirmed the diagnosis of carcinoma ex pleomorphic adenoma. There is no evidence of recurrence 12 months after operation. Pleomorphic adenoma, Malignant transformation, Squamous cell carcinoma, Case report 57 62 http://jbrms.medilam.ac.ir/browse.php?a_code=A-10-154-3&slc_lang=en&sid=1 Sara Amanpour saraamanpour@gmail.com 10031947532846001380 10031947532846001380 No 1. Department of Oral and Maxillofacial Pathology, School of Dentistry, Kerman University of Medical Sciences, Kerman, Iran Sorena Fardisi Sorenafardisi22@yahoo.com 10031947532846001381 10031947532846001381 No Department of Oral and Maxillofacial Surgery, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran. Reza Tabrizi rezatabrizz@gmail.com 10031947532846001382 10031947532846001382 No 3. Department of Oral and Maxillofacial Surgery, School of Dentistry, Shahid Beheshti University of Medical Sciences, Tehran, Iran Mohammad Reza Zarei Zarei66@yahoo.com 10031947532846001383 10031947532846001383 No 4. Department of Oral Medicine, Kerman Oral and Dental Diseases Research Center, Kerman, Iran. Maryam Raoof maryam.raoof@gmail.com 10031947532846001384 10031947532846001384 Yes 5. Laboratory of Molecular Neuroscience, Neuroscience Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences, Kerman, Iran Roya Khatami maryam.raoof@gmail.com 10031947532846001385 10031947532846001385 No