Multiple odontogenic keratocysts: report of a case

Although odontogenic keratocysts are common in clinical practice, the simultaneous occurrence of multiple cysts in both the maxilla and mandible of a patient is rare. We report a case of an otherwise healthy individual who developed 17 cysts over 15 years.     

Ultrastructure of odontogenic keratocysts.

The ultrastructural features of an odontogenic keratocyst are described. The results of the investigation suggest that the basal lamina complex in the odontogenic keratocyst appears to be morphologically normal. The frequently observed splitting of the epithelium from the capsular tissue is marked by the separation of the epithelium and the basal lamina complex from the connective tissue. The morphologic features of the parakeratinized surface zone of the epithelium suggest that the odontogenic keratocyst may be characterized by "incomplete" parakertinization.     

The multifocal nature of odontogenic keratocysts

The odontogenic keratocyst, OKC, is a very aggressive intraosseos lesion with a recurrence rate of approximately 25 percent to 60 percent.' The tendency for this lesion to "return" after surgical treatment has prompted studies to obtain more information concerning the inherent nature of the lesion. The OKC lesions are usually treated with enucleation of the soft tissue lining, curettage and ostectomy of the bony margins, or with more aggressive block resection. The purpose of this study was to characterize the multifocal aspect of the OKC and to demonstrate the presence of cystic lesions remote from the margins of the primarily diagnosed cyst itself. A retrospective chart review was conducted of seven patients who had sustained a long history of recurrent OKCs. Three types of documentation were reviewed for each patient: Orthopantomograms, cephalograms, and CT scans, which had been taken over the long-term course of the disease, Detailed operation reports of surgical procedures to treat the OKC lesions, and; Large histologic specimens from the six patients who received total resection of the involved mandibular bodies. These hemimandibulectomy slides offered a unique opportunity to observe OKC activity throughout a wide osseous area. All patients hod been operated multiple times over a period of 10 to 21 years, coming eventually to mandibular resection. The operating surgeon in all of the cases was one of the authors, Philip J. Boyne, DMD, MS, DSc. All patients exhibited the multifocal nature of OKCs with demonstrable cyst formation at distant sites in the mandible. Two patients had local recurrences at the margins of the primary lesion in addition to cyst formation at distant sites. The authors concluded that clinicians should respect the multifocal nature of OKCs. The "recurrences" observed in OKCs may not necessarily be due to the degree of skill of the surgeon or the technique used to eradicate the primary cyst, but instead are probably a reflection of the multifocal nature of the pathologic lesion itself. The OKC is a very aggressive intraosseos lesion of the jaws, which not infrequently clinicians detect in the process of routine oral examination.     

The experimental production of odontogenic keratocysts

Abstract. In the course of transplantation studies using tooth germs from isologous mice, it was shown that as the tooth germs developed to form teeth, cysts also formed in the epithelium of the enamel organs. It was found that, these cysts were producing keratin. Cysts developed in association with all the developing tooth germs, and by 120 days post-transplantation many of the cysts had completely enveloped the crowns of the developing teeth. It has been clearly demonstrated that in addition to enamel production, tooth germ epithelium is capable of cystic change and keratin formation. As many histological similarities exist between the experimentally induced keratin producing cysts and human odontogenic keratocysts, it is suggested that the development of the experimentally induced cysts from enamel organs actively involved in amelogenesis may be of direct significance to the etiology of human odontogenic keratocysts.     

Multiple odontogenic keratocysts of the jaws

Single odontogenic cysts are very well documented in the literature. Of those less common reports concerning multiple jaw cysts, many have been associated with systemic conditions or syndromes such as Gorlin-Goltz or basal cell naevus syndrome, Hunter's syndrome and mucopolysaccharidosis, for example, Maroteaux-Lamy syndrome. A case of multiple odontogenic keratocysts unassociated with any syndrome is reported so as to add to the growing number of such cases in the literature. The possibility of this case being a partial expression of the Gorlin-Goltz syndrome is discussed.     

Marsupialization for odontogenic keratocysts: long-term follow-up analysis of the effects and changes in growth characteristics

OBJECTIVE: This study evaluated the effects of marsupialization on odontogenic keratocysts (OKCs) and its role in conjunction with enucleation and curettage. STUDY DESIGN: Twenty-eight primary OKCs, treated by marsupialization before enucleation and curettage, were examined in this study. The effect of marsupialization and recurrence data after a follow-up period of at least 3 years were evaluated. The changes of growth characteristics during marsupialization were analyzed by means of histopathologic and immunohistochemical studies with monoclonal anti-Ki-67 antibody. RESULTS: The effect of marsupialization was evaluated as extremely effective (64.3%), moderately effective (32.1%), and poorly effective (3.6%). In 5 lesions, the cysts disappeared macroscopically and further surgery was not done. Recurrence was observed in 6 lesions (21.4%), and there was no significant difference in recurrence rates between the lesions treated with or without marsupialization. There appeared to be a predilection for recurrence in the lesions in the mandibular ramus region and also for radiographically multilocular lesions. Microscopic examination showed substantial changes from a parakeratinized or orthokeratinized epithelium into a hyperplastic, stratified, nonkeratinizing squamous epithelium after marsupialization in many cases. There was no significant difference in labeling index between premarsupialization (20.2% +/- 12.0%) and postmarsupialization (15.3% +/- 10.3%). CONCLUSION: Marsupialization was found to be effective as a preliminary treatment for large OKCs. This procedure does not appear to affect the recurrence tendency of OKCs, and the probable changes in growth characteristics become rather less aggressive.     

The conservative management of large odontogenic keratocysts

Odontogenic keratocysts, although well recognised to have a high recurrence rate are not invasive tumours and should not be treated by radical surgery with its attendant morbidity. Four cases of successful management by marsupialisation, and three examples of successful enucleation and packing are described, suggesting that conservative methods can be used in the treatment of large odontogenic keratocysts.     

The implications of inflammation in odontogenic keratocysts

The histologic features of 112 odontogenic keratocysts (OKC's) were examined from both a clinical and histopathological perspective with emphasis on the microscopic presence of inflammation and its relationship to transformation of the classic epithelial cyst lining found in OKC's to a nonkeratinized lining characteristic of common inflammatory odontogenic cysts. Eighty-five (76%) of these cases exhibited inflammation. The sensitivity of inflammation as a predictor of this aforementioned transformation is 100%, and its positive predictive value is 88%. The specificity of the same parameters remains high at 73%. Using previous studies, the implications of these findings on the biologic behavior of OKC's is discussed with special reference to therapeutic considerations.     

Effects of positive pressure in odontogenic keratocysts

Intracystic fluid pressure is thought to be involved in odontogenic cyst growth. In this study, we investigated the effects of positive pressure on the expression of interleukin-1alpha (IL-1alpha), matrix metalloproteinases (MMPs), and prostaglandin E2 (PGE2) in odontogenic keratocysts to determine whether this pressure stimulates inflammatory cytokine production and signaling of osteoclastogenic events. Positive pressure enhanced the expression of IL-1alpha mRNA and protein in odontogenic keratocyst epithelial cells, and increased the secretion of MMP-1, MMP-2, MMP-3, and PGE2 in a co-culture of odontogenic keratocyst fibroblasts and the epithelial cells. The pressure-induced secretions were inhibited by an interleukin-1 receptor antagonist. Recombinant human interleukin-1alpha (rhIL-1alpha) increased the secretion of MMP-1, MMP-2, MMP-3, and PGE2 in the fibroblasts. Furthermore, in the fibroblasts, rhIL-1alpha enhanced the expression of macrophage colony-stimulating factor (M-CSF) mRNA, and rhIL-1alpha-induced PGE2 increased the expression of nuclear factor kappaB ligand (RANKL) mRNA. Thus, positive pressure may play a crucial role in odontogenic keratocyst growth via stimulating the expression of IL-1alpha in epithelial cells.     

The implications of inflammation in odontogenic keratocysts

The histologic features of 112 odontogenic keratocysts (OKC's) were examined from both a clinical and histopathological perspective with emphasis on the microscopic presence of inflammation and its relationship to transformation of the classic epithelial cyst lining found in OKC's to a nonkeratinized lining characteristic of common inflammatory odontogenic cysts. Eighty-five (76%) of these cases exhibited inflammation. The sensitivity of inflammation as a predictor of this aforementioned transformation is 100%, and its positive predictive value is 88%. The specificity of the same parameters remains high at 73%. Using previous studies, the implications of these findings on the biologic behavior of OKC's is discussed with special reference to therapeutic considerations.     

Lectin histochemistry of ameloblastomas and odontogenic keratocysts

The cell membrane carbohydrate components of 10 simple (follicular and/or plexiform pattern) and 5 acanthomatous ameloblastomas, one plexiform unicystic ameloblastoma, one soft tissue ameloblastoma and 11 odontogenic keratocysts were studied in paraffin-embedded tissues using horseradish peroxidase-conjugated lectins. The presence of glucose and mannose was demonstrated by intense labelling with Concanavalin ensiforme (Con A) in 73% of the ameloblastomas examined, while periodate oxidation of the specimens prior to Con A (PA/Con A) stained 53% of the cases. Ameloblastomas did not express receptors for Triticum vulgaris (WGA), Erythrina chrystagalli (ECA), Arachis hypogea (PNA), and Ulex europaeus (UEA-1). The plexiform unicystic ameloblastoma and the soft tissue ameloblastoma examined showed the same cell membrane glycoproteins as the simple and acanthomatous ameloblastomas. Forty-five per cent of the keratocysts demonstrated Con A reactivity from the basal to the keratinized layer, while 72% of these specimens showed positive PA/Con A reactivity from the parabasal to the keratinized layer. Staining with WGA, ECA, PNA, and UEA lectins also revealed the presence of N-Acetyl-glucosamine and fucose oligosaccharides in the plasma membrane of basal, spinous and keratinized cell layers of the odontogenic keratocysts. The distinct cell surface carbohydrate composition of the ameloblastoma and odontogenic keratocyst may be responsible for the differences in biological behavior in these conditions.     

Scanning electron microscopic study of odontogenic keratocysts

Three odontogenic keratocysts were examined with a scanning electron microscope (SEM) on their surface cells, prickle cells, basal cells, and the epithelial-connective tissue interface. The microridges of the surface cells had a short, discontinuous, branched or beaded appearance. Intracellularly, the flattened keratinized cells formed a network consisting of delicate microfilaments. The prickle cells had numerous cytoplasmic projections and a large round nucleus that occupied most of the cytoplasm. The basal cells had two types of cytoplasmic process and a large oval polarized nucleus. The epithelium and the lamina propria were connected by a fibrous and fibrillar network.     

Cartilage in the walls of odontogenic keratocysts

Only one histologically documented case of cartilage in the wall of an odontogenic keratocyst has been reported in the English language literature. Four new cases are presented with the clinical, radiographic and histopathologic features described. To our knowledge this finding has not been reported in association with any other type of odontogenic cyst.     

Agnor as a marker of malignant transformation in odontogenic keratocysts

Nucleolar Organizer Region (AgNOR) counts have been reported as a useful, complementary diagnostic tool for several neoplasias. The morphometric evaluation of AgNOR has also been shown to contribute to the detection of incipient cellular alterations. The aim of the present study was to perform a morphometric analysis of AgNOR in keratocysts (KC), and in three rare cases of malignant transformation of keratocysts (KCm) to explore their use as a marker of the process of malignant transformation in this entity. We performed a study of the 3 cases of keratocysts that had suffered transformation into squamous cell carcinoma (SCC) that were available in our files and of 8 cases of solitary keratocysts (KCs). Paraffin sections were silver stained and employed to perform a morphometric analysis of 7 parameters related to number, size and shape of AgNORs. A comparative analysis of the epithelium of solitary keractocyts (KCs), the cystic epithelium adjacent to the area of transformation (KCm) and the epithelium of the SCC cords was performed. The epithelia of KCs and KCm exhibited statistically significant differences for four of the parameters analyzed: nuclear volume (VNUC), single AgNOR volume (VNOR), Total AgNOR per nucleus (TVNOR) and Contour Index of nuclei (CINUC). KCs and SCC exhibited statistically significant differences for all of the parameters. Given the ease with which this technique can be applied to routine histopathological material, we propose AgNOR evaluation as a diagnostic and prognostic aid in cystic entities that are suspected to have a neoplastic potential.     

Clinicopathologic study of odontogenic keratocysts in Singapore and Malaysia

This was a retrospective study of odontogenic keratocysts in people from the Singapore-Malaysian region. The purpose of this study was to present the clinicopathologic features of odontogenic keratocysts in the Oriental population and to compare these data with those from other reported studies. Biopsy records from 1981 to 1992 of 61 cases of odontogenic keratocysts from patients in Malaysia and Singapore showed that 42.6% of patients were female and 57.4% of patients were male. Among patients with cysts, 75.4% were Chinese, 6.6% were Malays, 9.8% were Indians and 8.2% were other ethnic groups. The mean age of these patients was 26.98 +/- 15.38 years with a peak incidence occurring in the second to fourth decades. The location of the lesions was more often in the mandible (65.5%) than the maxilla (31.0%). There was a marked predilection for lesions to occur in the posterior mandible. Histologically, 90.2% of the cysts were lined with a para-keratinized stratified squamous epithelium while only 3.3% of the cysts were lined with orthokeratinized stratified squamous epithelium. Mixed para-keratinized and orthokeratinized epithelial linings were observed in 4 cases (6.5%). The cyst linings were mainly uninflamed (95.1%). Inflammation of the cyst wall was found in 42 cases (68.8%). Twelve (19.7%) cases contained keratin in the lumen. A satellite cyst was observed in only 6 cases (9.8%). In conclusion, most clinical and histological features seen in this study were similar to those found for Caucasians. The only clinical feature that was different was the peak age incidence, that ranged from the second to fourth decades, with an absence of a second peak. Odontogenic keratocysts presenting at the site of the dentigerous cyst were observed in 7 cases (11.5%).