Squamous cell carcinoma arising in a dentigerous cyst in a 16-month-old girl

Squamous cell carcinoma arising in a dentigerous cyst is a rare lesion with distinct histopathology and stringent criteria for diagnosis.(1,2) During the past century, <60 cases have been reported.(3) Of the previously documented cases, all have occurred in adults. We present the case of a squamous cell carcinoma arising in a dentigerous cyst in a 16-month-old girl. This case poses interesting questions regarding the pathophysiology of these tumors and highlights the importance of maintaining a high index of suspicion regardless of age when evaluating cystic lesions of the mandible and maxilla.

CD1a-positive cells in odontogenic cysts

Langerhans cells (LC) are bone marrow-derived cells that have a CD1a-positive immunophenotype and are an important portion of the cell-mediated immune response. The aim of this study was an immunohistochemical evaluation of CD1a positive cells in different types of oral cysts. Fifty-five cysts were studied: 18 odontogenic keratocysts (OKC), of which five were orthokeratotic and 13 parakeratotic; 19 radicular cysts; and 18 dentigerous cysts. Positive LC was 80% for orthokeratotic OKC, 33% for parakeratotic OKC, approximately 35% for radicular cysts, and approximately 20% for dentigerous cysts. The results show that OKC with well-differentiated epithelial linings presented a greater number of LC than the other cysts. However, when the cyst wall was inflamed there were no differences in LC expression in the different types of cysts. The data confirm that LC distribution seems to be associated with the degree of differentiation of the epithelia.

Ki-67 expression in dentigerous cysts, unicystic ameloblastomas, and ameloblastomas arising from dental cysts

This study investigated whether or not an ameloblastoma developing in the wall of a dentigerous cyst is a distinct lesion from the unicystic ameloblastoma. An immunohistochemical evaluation of Ki-67 in dentigerous cysts, unicystic ameloblastomas, and ameloblastomas arising in dentigerous cysts was done. The values of Ki-67 positivity were 3.14 for the dentigerous cyst, between 5.32 and 16.56 for unicystic ameloblastoma, and 11.77 for ameloblastoma arising in a dentigerous cyst. Statistically significant differences were found between the dentigerous cyst and the unicystic ameloblastoma and between the dentigerous cyst and the ameloblastoma arising from a dentigerous cyst. No statistically significant difference was present between unicystic ameloblastoma and ameloblastoma arising from dentigerous cyst. These immunohistochemical data confirm the hypothesis that an ameloblastoma arising from a dentigerous cyst has a similar biological behavior to the unicystic ameloblastoma and should be considered as merely a histologic variant.

Bilateral mandibular cysts associated with cyclosporine use: a case report

Cyclosporin A (CsA) is used in the treatment of patients undergoing renal transplantation. There are a number of side effects associated with its use. In particular, the gingival overgrowth represents the most important in the oral cavity. The authors present a case of bilateral mandibular cysts in an 8-year-old boy, treated with CsA after renal transplantation. The genesis of the mandibular cysts might be associated with the combined use of CsA and a calcium channel blocker post-transplantation. CsA-induced gingival overgrowth might contribute to cysts by two mechanisms: interference with control mechanisms that regulate the reabsorption of gingival stromal tissue, allowing progressive dental eruption, and an increase in the gingival connective tissue components. Gingival hypertrophy might mechanically obstruct the eruption of the developing tooth.

Pathologic changes in the pericoronal tissues of unerupted third molars

OBJECTIVE

The purpose of this study was to determine whether the incidence of pathologic conditions affecting the pericoronal tissue of unerupted third molars justifies their routine removal.

METHOD AND MATERIALS

The pericoronal tissue associated with completely unerupted third molars was submitted for histologic examination after surgical tooth removal was performed in 37 males and 55 females, aged 13 to 63 years. The 104 unerupted third molars comprised 68 mandibular third molars (65.38%) and 36 maxillary third molars (34.62%).

RESULTS

The incidence of normal tissue of a dental follicle was 41.35%, and the incidence of pathologic tissue was 58.65% (dentigerous cyst, 50.96%; chronic nonspecific inflammatory tissue, 4.81%; odontogenic keratocyst, 1.92%; ameloblastoma, 0.96%). The incidence of pathologic conditions was higher than that of normal conditions in all third molar positions. In younger patients, normal tissue was more commonly found, but in patients older than 20 years, the incidence of pathologic tissue was higher than the incidence of normal tissue.

CONCLUSION

Unerupted third molars should be removed before pathologic changes can occur in their pericoronal tissues. This justifies routine removal of unerupted third molars from patients older than 20 years.

Immunohistochemical localization of fibroblast growth factors FGF-1 and FGF-2, and receptors FGFR2 and FGFR3 in the epithelium of human odontogenic cysts and tumors

Acidic (FGF-1) and basic (FGF-2) fibroblast growth factors are members of a family of growth factors that function in growth, differentiation and regeneration of a variety of tissues. Their presence in human odontogenic cysts and tumors has not been previously investigated. This study was designed to detect immunohistochemically the presence of these factors and two fibroblast growth factor receptors (FGFR2 and FGFR3) in a cross section of odontogenic cysts and tumors, to determine if they may be involved in the differentiation of odontogenic epithelium or, more specifically, in the development of particular cysts or tumors. Archival formalin-fixed paraffin-embedded tissues were used. With some exceptions, FGF-2 and the receptor FGFR2, were found in the cytoplasm and occasionally in the nuclei of cells of odontogenic epithelium, while FGF-1 and the receptor FGFR3, were absent or only focally or weakly detected, using standard immunohistochemical techniques. The data are similar to those published for normal murine odontogenesis, suggesting that these factors are associated with odontogenic differentiation rather than pathogenesis. The presence of significant nuclear staining in odontogenic epithelium associated with embryonic mesenchyme in ameloblastic fibromas and ameloblastic fibro-odontomas suggests that FGF-2 may be involved in directing nuclear activity at the histodifferentiation stage of odontogenesis.

An aggressive dentigerous cyst in a seven-year-old child

A review of literature indicates that very few of these cysts are found in children less than ten years of age, in spite of the fact that the cysts are associated with the eruption and/or formation of the secondary dentition. Although dentigerous cysts are rare in the first decade of life, a thorough review of a child's initial radiographs is of obvious importance as indicated by this case report. Of prime importance in this matter is the age at which the initial panoramic radiographic examination is performed on a child. According to the guidelines recommended by the American Academy of Pediatric Dentistry, the first panoramic radiographic examination should be performed following the eruption of the first permanent tooth. In this case, the appropriate radiographic survey was not conducted. A proper survey should include: Proper exposure of the film. Proper development of the film. Proper interpretation of the film. This child had a quadrant of dentistry performed three months prior to the discovery of the lesion. The previous dental provider noted that a panoramic radiograph had been exposed. It is unclear whether all of the aforementioned steps were followed or completed in order for the provider to obtain the information needed to render a diagnosis, and to properly refer this patient for a more in-depth examination of her mandibular swelling. The mere fact that this child's right mandibular first molar was fully erupted and the left one had not erupted at all, would be reason enough to take a panoramic radiograph to investigate the cause of the clinical absence of the contralateral first molar. This article has presented a case in which a proper panoramic radiographic examination performed at the time of eruption of the first permanent tooth may have led to an earlier diagnosis of the cyst, and thus might have prevented the loss of multiple permanent teeth.

P53 protein expression in odontogenic cysts

p53 protein seems to be related to the suppression of cell proliferation. p53-positive tissues seem to have a higher proliferative activity than p53-negative ones. Odontogenic keratocyst (OKC) has a different behavior from other types of cysts because it is more aggressive, with a tendency to recurrence. Twenty-two dentigerous cysts, 24 radicular cysts, and 20 OKCs were used in the present study. Two dentigerous cysts (9.1%), 2 radicular cysts (8.3%), and 9 OKCs (45%) expressed the p53 protein. The differences between the three groups were statistically significant (p = 0.003). In 10 cases of OKCs epithelial dysplasia was found. One of the 10 OKCs without dysplasia and 8 of the 10 OKCs with dysplasia were p53-positive: the difference between the two groups was statistically significant (p = 0.007). The overexpression of p53 protein was not on the other hand correlated with the occurrence of multiple, bilateral, and recurrent OKCs. Moreover the distribution of p53-positive cells was parabasal in contrast with other types of cysts. These qualitative and quantitative differences in proliferative activity in OKCs seem to point to an alteration in cell cycle control.

[Ameloblastoma of the maxillary sinus. Apropos of a case]

The ameloblastoma is benign odontogen tumour developed from epithelial remains of MALASSEZ. Because of the inclination to invade in an inexorable way all the surrounding tissues and of the faculty of recurrence after removal, one attributes him the qualifier of good-hearted tumour to local wickedness. The mandibulary localization is the most frequent. Toward the maxillary, it is mostly observed in the tuberosity region. The authors report in the work one case of ameloblastoma developed from the pericoronal cyst of an intrasinusal ectopic canine tooth.

Follicular or dentigerous (tooth-containing) cyst in the premaxilla of an otherwise edentulous 65-year-old man

A unilocular follicular or dentigerous cyst (FDC) with a diameter of 12 mm was observed incidentally in the premaxilla of a midsagittal section of the head of a 65-year-old cadaver. The mucosal lining of the cyst was grey in color and granular in texture: the osseous walls had a thickness of less than 1 mm. In the floor of the cyst, a slender, fully developed incisor tooth was fixed in a horizontal position. The alveolar processes of the maxilla and mandible were completely edentulous. Postmortem computer tomography showed the cyst in an osteolytic lesion of the premaxilla, and histology revealed a lining of non-keratinized stratified squamous epithelium supported by a lamina propria of dense connective tissue.

Long-term follow-up on keratocysts treated according to a defined protocol

A prospective study was conducted on 82 odontogenic keratocysts (OKCs) diagnosed in 80 patients over a 25 year period. The clinical and radiographic data were correlated, which resulted in an accurate picture of the clinical presentation, relationship with teeth and incidence of lingual perforations in mandibular OKCs. In 40% of the cysts no suspicion had arisen before surgery, in 60% the diagnosis was secured before surgery. This last group of patients was treated according to a defined protocol, with the exception of the maxillary OKCs, which entailed excision of the attached, overlying mucosa and enucleation of the cyst after which the defect was treated with Carnoy's solution. The other patients underwent just enucleation of the cysts. For the first 5 years the patients were seen every year, thereafter every 2 years if possible. Recurrences (9/82) were mainly found in the patients in which the cyst had just been enucleated. Only three cysts recurred in the group treated according to the above mentioned protocol. Most recurrences presented within 5 years, but late recurrences did occur even after 25 years. The aetiology and pathogenesis of OKCs is briefly discussed in the light of the present findings. It is concluded that the suggested treatment protocol and follow-up schedule provides a safe means to manage a lesion that is known to recur and may even give rise to life threatening situations.

Odontogenic carcinoma occurring in a dentigerous cyst: case report and clinical management

This case report describes an unusual odontogenic carcinoma, which was detected during routine periodontal examination. The lesion occurred in a dentigerous cyst associated with an impacted third molar in an otherwise asymptomatic 66-year-old male patient. The impacted tooth and lesion were excised based on evidence of radiographic change and clinical findings. An unusual histopathologic presentation is reported. The treatment provided for this tumor and the management of impacted teeth is reviewed.

Interleukin-1alpha-dependent regulation of matrix metalloproteinase-9(MMP-9) secretion and activation in the epithelial cells of odontogenic jaw cysts

Interleukin-1alpha (IL-1alpha) and matrix metalloproteinase-9 (MMP-9) are thought to be involved in odontogenic cyst expansion. In this study, we investigated the effects of IL-1alpha on the secretion and activation of MMP-9 in odontogenic jaw cysts. An active form of MMP-9 was present in odontogenic keratocyst (6 of 8 cases) fluids more frequently than dentigerous cyst (3 of 10 cases) and radicular cyst (3 of 10 cases) fluids, although proMMP-9 was present in all cyst fluids. Odontogenic keratocyst fragments in explant culture secreted a larger amount of IL-1alpha than dentigerous cyst and radicular cyst fragments in explant culture, and spontaneously secreted both proMMP-9 and an active form of MMP-9. The fragments of dentigerous cysts and radicular cysts secreted a small amount of proMMP-9, but no active form of MMP-9. Exogenously added recombinant human IL-1alpha (rhlL-1alpha) increased the secretion and activation of proMMP-9 in the fragments of dentigerous cysts and radicular cysts. The epithelial cells isolated from odontogenic keratocysts secreted IL-1alpha and proMMP-9 without stimulation. Under the cultivation on a fibronectin-coated dish, rhIL-1alpha increased the secretion of proMMP-9 from the epithelial cells in a dose-dependent manner. Moreover, rhIL-1alpha induced the secretion of proMMP-3 and plasminogen activator urokinase (u-PA) from the epithelial cells, and converted the secreted proMMP-3 to the active form in the presence of plasminogen. The secreted proMMP-9 was also activated in the presence of rhIL-1alpha and plasminogen. Hence, our results suggest that IL-1alpha may up-regulate not only proMMP-9 secretion but also proMMP-9 activation by inducing proMMP-3 and u-PA production in the cyst epithelial cells by autocrine/paracrine regulatory mechanisms.

Early soft tissue pathosis associated with impacted third molars without pericoronal radiolucency

OBJECTIVES

This study was performed to histologically evaluate soft tissue pathosis in pericoronal tissues of impacted third molars that did not exhibit pathologic pericoronal radiolucency.

STUDY DESIGN

One hundred impacted third molars without evidence of abnormal pericoronal radiolucency (follicular space <2.0 mm) were removed for reasons other than participation in this study, and the pericoronal tissues were submitted for histopathologic examination. Specimens were fixed and processed routinely and were stained with hematoxylin and eosin before independent evaluation by each of 2 oral pathologists. A subset of both diseased and healthy tissues underwent additional evaluation for the presence of proliferating cell nuclear antigen (PCNA) for assessment of cellular activity.

RESULTS

Of the specimens submitted, 34% showed squamous metaplasia suggestive of cystic change equivalent to that found in dentigerous cysts. Soft tissue pathosis was significantly higher in patients over 21 years of age (P =.001). Five of 8 diseased specimens demonstrated PCNA uptake, whereas none of 10 healthy specimens were PCNA positive.

CONCLUSIONS

These findings suggest that radiographic appearance may not be a reliable indicator of the absence of disease within a dental follicle. We conclude that the incidence of soft tissue pathologic conditions is higher than generally assumed from radiographic examination alone.

Dentigerous cyst with an impacted canine in an unusual position-a case report

A dentigerous cyst is a type of an odontogenic cyst associated with the crown of an impacted, embedded or unerupted tooth. In this article, we report a case of dentigerous cyst with an impacted canine in an unusual position which was surgically removed.

Case report of a pigmented dentigerous cyst and a review of the literature on pigmented odontogenic cysts

This paper reports the first case of a dentigerous cyst containing melanin-pigment and melanocytes in the lining epithelium, and the first case of a odontogenic cyst with macroscopically visible pigmentation in the cyst wall. The patient was a 29-year-old Japanese male with a cystic lesion in the left retromolar area of the mandible. Pathologic examination revealed the lesion to be a dentigerous cyst with or without mild surface keratinization, and numerous granules of melanin-pigment were distributed in the basal cells of the epithelial lining. Furthermore, dendritic melanocytes were scattered in the basal layer. Review of the literature revealed that pigmented odontogenic cysts are uncommon, and only 11 cases have been documented; eight were odontogenic keratocyst, one was a gingival cyst, one was a botryoid odontogenic cyst, and one was a lateral periodontal cyst. The possible origin of melanocytes in odontogenic lesions is discussed.

Immunohistochemical study of bcl-2 protein, Ki-67 antigen and p53 protein in epithelium of glandular odontogenic cysts and dentigerous cysts

The aim of the present study was the evaluation of the immunohistochemical expression of the apoptosis-inhibiting protein bcl-2, the cell-cycle-related antigen Ki-67 and the p53 protein, which is involved both in cell cycle and apoptosis regulation, in the lining epithelium of glandular odontogenic cysts of the jaws. Formalin-fixed and paraffin-embedded tissue sections of three glandular odontogenic cysts and six dentigerous cysts were immunostained with a standard avidin-biotin peroxidase procedure, after microwave antigen retrieval. The glandular odontogenic cysts showed immunoreactivity for bcl-2 protein in the basal and suprabasal layers, while staining in dentigerous cysts was basal or focal. Most mucous cells and superficial cuboidal cells were negative. The percentage of Ki-67- or p53-positive cells was lower in glandular odontogenic cysts compared with dentigerous cysts. The findings suggest that the biological behavior of glandular odontogenic cysts may be associated with deregulation of cell death in the lining epithelium, while cell proliferation and p53 status do not seem to play a significant role.

Collagen fibres in the wall of odontogenic keratocysts: a study with picrosirius red and polarizing microscopy

The collagen in the walls of 15 keratocysts was studied histochemically by staining sections with picrosirius red and examining them with polarizing microscopy. This was compared to 15 cases of dentigerous cyst and 15 cases of radicular cyst. Polarization colours of the collagen fibres were recorded according to their width. No differences were found between the polarization colours of thin fibres (<0.8 microm) in all three lesions; the polarization colours of thick fibres (1.6-2.4 microm) in keratocysts were significantly more greenish-yellow when compared with those of dentigerous cysts and radicular cysts. The staining of the collagen fibres in the keratocysts is similar to that reported in odontogenic neoplasms, which suggests that the stroma of keratocysts could be regarded not just as a structural support of the cyst wall, but as playing a part in the neoplastic behaviour of the cyst.

Pathologic change in soft tissues associated with radiographically 'normal' third molar impactions

Our aim was to evaluate the incidence of histological abnormalities in soft tissues surrounding impacted third molar teeth when there were no pathological conditions apparent on the corresponding radiographs. Ninety-six dental follicles were collected from third molar teeth of 63 patients. No tooth had a follicular space greater than 2.4 mm as measured on the panoramic radiograph. Specimens were examined by each of three oral pathologists, and only those independently diagnosed as cystic by all three pathologists were considered diseased. A diagnosis of dentigerous cyst was made in 31 cases; 22 of 60 mandibular specimens (37%) and nine of 36 maxillary specimens (25%) were affected. No disease other than dentigerous cyst was seen. We conclude that the incidence of dentigerous cyst associated with impacted third molar teeth is higher than reported in radiographic studies alone. The importance of histological diagnosis of dentigerous cyst should be evaluated further in the light of this unexpectedly high incidence of microscopic disease.