Published online Jul 6, 2019. doi: 10.12998/wjcc.v7.i13.1686
Peer-review started: February 15, 2019
First decision: March 9, 2019
Revised: March 27, 2019
Accepted: May 1, 2019
Article in press: May 1, 2019
Published online: July 6, 2019
Processing time: 143 Days and 21.2 Hours
Orthokeratinized odontogenic cyst (OOC) is a benign odontogenic cyst. It is a variant of the common odontogenic keratocyst (OKC). This case report describes a rare malignant transformation of OOC, with the aim of raising awareness of the malignant potential of OOC and distinguishing it from OKC.
In August 2018, a 52-year-old man was referred to the Department of Oral Maxillofacial and Head–Neck Oncology of Wuhan University. The patient presented with severe pain in the left mandible for 2 mo, and had a 5-year history of osteomyelitis and mandibular cyst with three recurrences. His latest diagnosis by pathological examination was OOC of the left mandible with mild-to-moderate local proliferation. However, the cyst showed malignant potential by radiographic examination. We performed partial mandibulectomy and sent the lesion tissue for pathological examination. As expected, the cyst had deteriorated to moderately differentiated squamous cell carcinoma. During postoperative follow-up, the patient went for chemotherapy in September 2018 and successfully completed four cycles.
Surgeons should be more aware of OOC, which is usually benign but can become malignant.
Core tip: Orthokeratinized odontogenic cyst (OOC) is a benign odontogenic cyst that rarely undergoes malignant transformation. In order to highlight the malignant potential of OOC, especially in patients with a history of recurrence and inflammation, we describe a rare case of recurrent OOC that transformed into squamous cell carcinoma after the patient underwent curettage twice.