Calcifying epithelial odontogenic (Pindborg) tumor with malignant transformation and metastatic spread

Background. Pindborg tumors (calcifying epithelial odontogenic tumors) are uncommon neoplasms of odontogenic origin most often located in the posterio r mandible. First described in detail in 1955 by Pindborg, these tumors are considered benign but can be locally aggressive in nature, with recurrence rates of 10% to 15% reported. The malignant form of this tumor is exceedin gly rare, Methods. We describe the case of a 84-year-old woman initially treated for a painful infected left mandibular third molar. The patient underwent extra ction of the tooth and excision of an associated soft tissue component. Sub sequent histologic review identified a Pindborg tumor of the left posterior mandible. Results. After initial excision, this tumor recurred twice, with the recurr ences exhibiting a progression to a malignant Pindborg tumor (odontogenic c arcinoma) with vascular invasion and spread to a cervical lymph node. Furth er treatment involved radical surgery and adjuvant radiotherapy. At last re view 12 months after treatment, the patient was disease free. Conclusions. This article describes only the second case of odontogenic car cinoma. The transformation from benign to malignant histologic findings has not previously been documented in this tumor. The salient clinical feature s of this case are presented along with supportive pathologic and radiologi c evidence. (C) 2001 John Wiley & Sons, Inc.