Tehran University of Medical Sciences Journal of Craniomaxillofacial Research 2345-5489 12 4 2026 02 09 288 291 Hasti Sarabi Kia Department of Oral and Maxillofacial Surgery, School of Dentistry, Isfahan University of Medical Sciences, Isfahan, Iran. Arash Esmaeili Department of Oral and Maxillofacial Surgery, School of Dentistry, Isfahan University of Medical Sciences, Isfahan, Iran. Bahareh Fattahi Department of Oral and Maxillofacial Pathology, School of Dentistry, Kashan University of Medical Sciences, Kashan, Iran. Shahram Sarkhosh Department of Oral and Maxillofacial Surgery, School of Dentistry, Isfahan University of Medical Sciences, Isfahan, Iran. 2025 10 30 2026 01 24 This case report elucidates the significant oncologic risk associated with long-standing pleomorphic adenoma (PA), wherein the cumulative risk of malignant transformation to carcinoma ex pleomorphic adenoma (CXPA) escalates over time. It details the management of a 46-year-old female with a 25-year history of a palatal mass, which exhibited recent rapid growth—a key clinical warning sign. Diagnosis was confirmed via incisional biopsy following clinical and cone-beam computed tomography assessment, which revealed bony erosion. The patient was successfully treated with complete surgical excision, with final histopathology confirming a benign PA. The case underscores a critical clinical dilemma: delayed intervention for PA inadvertently heightens malignancy risk and complicates management. Consequently, this report strongly advocates for prompt diagnosis and definitive surgical excision upon initial detection of PA to preempt transformation and mitigate the profound prognostic implications of CXPA.  Keywords: Pleomorphic adenoma; Carcinoma ex pleomorphic adenoma; Palatal neoplasms. https://jcr.tums.ac.ir/index.php/jcr/article/view/576 https://jcr.tums.ac.ir/index.php/jcr/article/download/576/473