Keratocystic odontogenic tumour (KCOT) misdiagnosed as a dentigerous cyst

Abstract

SUMMARYKeratocystic odontogenic tumours are known for their peculiar behaviour, varied origin, debated development, unique tendency to recur and disputed treatment modalities. Thus, it has been the subject of much research over the last 40 years. It was formerly known as odontogenic keratocyst (OKC). OKC received its new title as keratocystic odontogenic tumour (KCOT) by the WHO (2005) in order to suggest its aggressive and recurrent nature. KCOT is a benign intraosseous neoplasm of the jaw. Involvement of the maxillary sinus is an unusual presentation. We present the case of an 11-year-old child with extensive KCOT and an impacted canine in the right maxillary sinus. The cyst was initially misdiagnosed to be a dentigerous cyst based on the clinical and radiographic features though a differential diagnosis of KCOT and adenomatoid odontogenic tumour was made. The histological examination of the specimen finally confirmed it to be a KCOT. The clinical, radiological and histological features of this tumour along with its surgical management have been discussed. BACKGROUND

Keratocystic Odontogenic Tumor of the Maxillary Anterior Region Masquerading as a Radicular Cyst

“…Till date, only a handful of cases has been reported of KCOT crossing maxillary midline [6]. When KCOT occurs in maxilla, diagnostic difficulties arise owing to lack of characteristic clinical and radiographic features [2]. The maxillary KCOTs are usually smaller in size.…”

“…It was reclassified by WHO (2005) as a benign tumor, and the use of term KCOT was recommended as it reflects on its neoplastic nature [1]. Often due to atypical clinical and radiographic presentations, KCOTs have been misdiagnosed as odontogenic cysts (viz., dentigerous cyst, radicular cyst, and lateral periodontal cyst) and have been undertreated [2][3][4]. Since KCOT has an aggressive biological behavior, it is essential to distinguish it from odontogenic cysts [5].…”

Giant keratocystic odontogenic tumor: a challenging diagnosis

“…Therefore, the best way to confirm its diagnosis is by recognizing its characteristic histopathologic features 2. The histopathologic features of KCOT are confirmatory with distinctly different epithelial lining.…”

“…However, in 1967, Toller suggested that the OKC should rather be regarded as a benign neoplasm and not as a typical cyst 2. Ever since Mikulicz presented the first case of OKC, in 1876, as a “dermoid cyst,” this interesting lesion has been the subject of debate owing to its varied origin, debated development, peculiar behavior, unique tendency to recur, and disputed treatment modalities 3…”

Expression of p73 and TRAIL in odontogenic cysts and tumors

“…In fact, dentigerous cyst and KCOT can share clinical and radiological features; furthermore, KCOT may have the gross appearance of a dentigerous cyst in some cases, so that a correct diagnosis can only be made by histopathological analysis (5).…”