J Maxillofac Oral Surg 8(2):127–131 127 REVIEW Keratocystic odontogenic tumor: a Suhas S Godhi1 · Pankaj Kukreja2 1 Professor review 2 Senior Lecturer Dept. of Oral and Maxillofacial Surgery, ITS Centre for Dental Studies and Received: 16 January 2009 / Accepted: 10 May 2009 Research, Uttar Pradesh © Association of Oral and Maxillofacial Surgeons of India 2009 Abstract The odontogenic keratocyst is a very well known odontogenic cyst. There are many types of cysts of the jaws, but what makes the odontogenic keratocyst unusual are its characteristic histopathological and clinical features, including potentially aggressive behaviour, high recurrence rate, and an association with the nevoid basal cell carcinoma syndrome. The characteristic histologic Address for correspondence: feature i.e. the presence of parakeratin, is unique amongst all the different inflammatory and developmental cysts that occur in the jaws. Many treatment Suhas S Godhi modalities have been advocated for its treatment, but none in particular has been Dept. of Oral and Maxillofacial Surgery I.T.S Centre for Dental Studies and regarded as the best treatment option. The 2005 WHO classification now uses the Research term ‘keratocystic odontogenic tumor’. We present a review of treatment modalities Muradnagar, Ghaziabad of the KCOT. Uttar Pradesh - 201206, India Ph: 09899450488 Keywords Odontogenic tumor · Cyst E-mail: [email protected] Introduction we present a review of treatment odontogenic tumor due to its tendency to modalities of the KCOT. recur. He suggested: Ever since Philipsen in 1956 first 1. Unilocular cysts to be treated by intra- described a cyst of the jaws lined by oral resection. keratinizing epithelium which was known Discussion 2. In areas of difficult access, as odontogenic keratocyst, surgeons have decompression and secondary been toiling to find an ideal treatment for Mikulicz in 1876 first described the KCOT enucleation is advocated. it. The knowledge regarding the treatment as a part of a familial condition affecting 3. Large multilocular cysts should be of the odontogenic keratocyst, now the jaws, but the term odontogenic treated by resection and primary bone renamed as the Keratocystic Odontogenic keratocyst was first introduced by graft. Tumor (KCOT) [51], has been ever Philipsen in 1956. In 1960, Shear [4] In a systematic review of the treatment increasing over the past few decades, and stated that, ‘in most respects, the diagnosis and prognosis, Blanas et al. [7] in 2000, yet, the issue is still a debate in oral and of primordial cysts is of academic have concluded that a simple enucleation maxillofacial surgery. Various treatment importance only. They are entirely simple results in an unnecessarily high recurrence modalities have been tried for the in nature and will not recur if enucleated. rate when treating the KCOT. For a routine successful treatment of the KCOT, ranging Since then, a wide range of treatment KCOT in a person who is likely to return from simple enucleation to resection, but modalities have been put forward for its for a follow-up treatment, Carnoy’s solution none has been regarded as the ideal treatment. appears to be the least invasive procedure treatment. The KCOT behaves like a tumor Eyre and Zakrzewska [5] in 1985, have with a lowest recurrence rate. If the lesion in many ways, for e.g. involvement of stated the following treatment options for is very large, decompression of the cyst large areas of the bone, high recurrence the KCOT - followed by enucleation will also have a rate, distinctive histopathological features 1. Enucleation: low recurrence rate. Use of Carnoy’s of the lesion, disregulation of the PTCH • with primary closure solution should also be considered at the (patched) gene in both Nevoid basal cell • with packing enucleation stage. If the patient is unlikely carcinoma syndrome associated and • with chemical fixation to return for follow-up, the lesion should sporadic odontogenic keratocysts, etc. On • with cryosurgery be resected. the other hand, successful treatment by 2. Marsupialization: Bradley and Fischer [8], in 1975, have marsupialization denies its tumor • only described the combined enucleation and characteristics. Truly, cases of carcinoma • followed by enucleation cryosurgical treatment of the KCOT. Webb arising in KCOT have been reported [1,2]. 3. Resection: and Brockbank [9] in 1984, have presented In fact, recurrence of the lesion has been Bramley [6], in 1971, proposed a the treatment of the KCOT of the mandible reported in a bone graft [3]. In this article, treatment plan for the keratinising cystic using a combination of enucleation and 123 128 J Maxillofac Oral Surg 8(2):127–131 cryosurgery. They have followed up the case for 5 years and have found no recurrence. They suggest that cryosurgery, as an adjunct to enucleation, may prove to be a conservative and reliable method of treatment with a low recurrence rate. Recurrence of the KCOT ranges from 2.5% [11,12] to 62% [10,12]. Different studies show different recurrence rates (Table 1). The possible mechanisms of Fig. 1 Preoperative radiograph Fig. 2 Postoperative radiograph (6 months) recurrence have been described by Voorsmit et al. [11] in 1981. These state that any lining epithelium left behind in the oral cavity may give rise to a new lesion formation. Daughter cysts, microcysts or epithelial islands can be found in the walls of the original cysts. New KCOTs may develop from epithelial offshoots of the basal layer of oral epithelium [12]. Fig. 3 Postoperative radiograph (12 months) Fig. 4 Postoperative radiograph (17 months) Both conservative approach as well as aggressive approach has been advocated for resection without continuity defects as a behind in the mucosa, which develop into the treatment of the KCOT. Conservative radical treatment, in which removal of the a new KCOT. approach, however, has not gained much cyst, teeth and the overlying soft tissue is Sometimes the KCOT may mimic the popularity, because complete removal of followed by packing of the resulting cavity appearance of an endodontic lesion. In a case the KCOT can be difficult because of the to minimize the risk of recurrence. reported by Pace R et al. [23] such a lesion thin friable lining, limited surgical access, Nakamura et al. [18] in 2002 have stated was successfully treated by complete skill and experience of the surgeon, and that Marsupialization, as well as enucleation and application of Carnoy’s desire to preserve adjacent vital structures. decompression, has the purpose of relieving solution. At 2-year follow-up, no clinical The goals of treatment should involve the pressure within the cystic cavity and signs or symptoms were found and the lesion eliminating the potential for recurrence allowing the new bone to fill the defect. It, had disappeared radiographically. Rai S and while also minimizing the surgical consequently, saves the contiguous structures Gauba K [24] have successfully treated a morbidity [13,14,15]. such tooth roots, the maxillary sinus or the case of jaw cyst bifid rib basal cell nevus Enucleation followed by chemical inferior alveolar canal can be saved from syndrome. Cystic changes can arise in cauterization using Carnoy’s solution along surgical damage. They have concluded in relation with unerupted lower third molars. with excision of overlying attached mucosa their study that marsupialization was highly Chye CH and Singh B [25] have described has been used for the treatment of KCOT. successful in reducing the size of the KCOT a case of a large KCOT which developed Stoelinga [16] in 2001 has concluded in a before surgery. It was more effective in the rapidly and aggressively over a short period long term follow up study that this method mandibular body than the ramus region. It of 2 years and presented with acute gave rise to a fairly low number of did not adversely affect the recurrence symptoms. The KCOT was enucleated and recurrences. Peripheral ostectomy tendency. The characteristics of the KCOT the residual cavity was treated with Carnoy’s combined with carnoy’s solution may give may become less aggressive during the course solution. Kumar M, Bandtopadhyay and nil recurrence rate [15]. In our experience, of marsupialization. Thapliyal GK [26] have reported a case of a we have treated a series of five patients by Some authors have advocated KCOT occurring in the anterior mandible, enucleation followed by chemical marsupialization as a viable treatment for an uncommon site, with the lesion crossing cauterization. All the cases radiographically the KCOT [19,20]. Pogrel and Jordan the midline being a unique occurrence. show a complete resolution of the lesion [20,21] in 2004, have treated 10 KCOTs In a retrospective study of 255 chinese (Figs. 1, 2, 3 and 4). The patients are still by marsupialization, and they found out that patients, Zhao YF et al. [27] have under periodic observation in our institute, all the 10 KCOTs resolved completely with concluded that KCOT treated with and show no signs of recurrence at present. this form of treatment alone. Their study enucleation alone have a higher recurrence A strict follow up protocol, which allows also suggested that the cyst lining may get rate. Enucleation with adjunctive treatment for early surgical intervention in case of replaced by normal epithelium during this can decrease recurrence rate. Radical recurrence, limits the extent of second treatment. excision has no recurrence but does have surgery and thus, gives rise to less According to Stoelinga [16,22], the highest morbidity rate and should be morbidity. It seems likely that offshoots of complete elimination of recurrences is reserved for multiple recurrent cysts after the basal layer of the epithelium of the oral probably not possible for two reasons. First, conservative means. mucosa are a major cause for the some cysts are still treated like ordinary Tolstunov and Treasure [28] have development of some KCOT and some odontogenic cysts because a preoperative advocated a surgical treatment algorithm recurrences.