Discovery of metabolite biomarkers for odontogenic keratocysts.

INTRODUCTION: Odontogenic keratocysts (OKCs) are locally aggressive and have a high rate of recurrence, but the pathogenesis of OKCs is not fully understood. We aimed to investigate the serum metabolomic profile of OKCs and discover potential biomarkers. METHODS: Metabolomic analysis was performed on 42 serum samples from 22 OKC patients and 20 healthy controls (HCs) using gas chromatography‒mass spectrometry to identify dysregulated metabolites in the OKC samples. LASSO regression and receiver operating characteristic (ROC) curve analyses were used to select and validate metabolic biomarkers and develop diagnostic models. RESULTS: A total of 73 metabolites were identified in the serum samples, and 24 metabolites were dysregulated in the OKC samples, of which 4 were upregulated. Finally, a diagnostic panel of 10 metabolites was constructed that accurately diagnosed OKCs (sensitivity of 100%, specificity of 100%, area under the curve of 1.00). CONCLUSION: This study is the first to investigate the metabolic characteristics and potential metabolic biomarkers in the serum of OKC patients using GC‒MS. Our study provides further evidence to explore the pathogenesis of OKC.

Transformation of an odontogenic keratocyst into a solid variant of odontogenic keratocyst/keratoameloblastoma during long­term follow­up: A case report.

Keratoameloblastoma (KA) and solid variant of odontogenic keratocyst (SOKC) are rare odontogenic lesions, and their relationship and differences are unclear. The present study described a case that started as an odontogenic keratocyst (OKC) and transformed to SOKC/KA upon recurrence. Briefly, a 26­year­old man presented with swelling in the right cheek and was referred to the Department of Oral and Maxillofacial surgery, Hiroshima University Hospital (Hiroshima, Japan). At the initial visit, unicystic bone permeation was observed extending from the right canine to the molar, maxillary sinus and nasal cavity. After the biopsy, the patient underwent excisional surgery and was diagnosed with OKC. Thereafter, the lesion recurred six times over a period of 13 years and showed different histopathological features from those of the primary lesion, all consisting of numerous cysts with keratinization, which were diagnosed as SOKC/KA. The Ki­67 positivity rate was ~10%, which was higher than that of the primary lesion, but there was no atypia. Genetic analysis of the recurrent lesion revealed mutations in adenomatous polyposis coli and Kirsten rat sarcoma viral oncogene homolog. This case originated from OKC, and the morphological features of OKC and KA were mixed upon recurrence, supporting the commonality and association between the two. However, multiple mutations different from those of OKC and ameloblastoma were detected, suggesting an association of SOKC/KA with increased proliferative activity and a high recurrence rate.

Pediatric Oral Pathology: Odontogenic Cysts.

Cysts encountered in the head and neck typically arise from epithelium that would normally be programmed to form teeth or tooth-supporting structures (odontogenic epithelium). These cysts come with a confusing array of similar-sounding names and histopathologic features that are sometimes shared between conditions. Here we describe and contrast the relatively-common lesions: hyperplastic dental follicle, dentigerous cyst, radicular cyst, buccal bifurcation cyst, odontogenic keratocyst, glandular odontogenic cyst, and the less-common gingival cyst of the new-born and thyroglossal duct cyst. The goal of this review is to help clarify and simplify these lesions for the general pathologist, pediatric pathologist, and surgeon.

Focal Abscess: Description of a clinical case.

Purpose The purpose of this article is to present a case report of a periapical lesion found in a 24-year-old female who presented to a university dental hygiene clinic with a chief complaint of vestibular pain around tooth #22. Radiographically, the lesion appeared radiolucent and unilocular with well-defined borders and significant bone resorption. The area of radiolucency increased in size over a period of five weeks indicating an aggressive pathosis. Given the clinical and radiographic presentations, the differential diagnosis included an odontogenic keratocystic tumor (odontogenic keratocyst), central giant cell granuloma, periapical cyst, and squamous cell carcinoma. Biopsy revealed the diagnosis of a focal abscess. The patient's presenting signs and symptoms are reviewed. Management and contributing factors are discussed.

A retrospective study of the malignant change of odontogenic keratocyst.

The odontogenic keratocyst (OKC) is a common cystic lesion of the maxilla and mandible. Squamous cell carcinoma (SCC) arising from OKC or dysplasia occurring in OKC is rare. This study aimed to explore the incidence and clinical features of the dysplasia and malignant transformation of OKC. In this study, 544 patients diagnosed with OKC were collected. Among them, 3 patients were diagnosed as SCC arising from OKC, and 12 patients were diagnosed as OKC with dysplasia. The incidence was calculated. Clinical features were analyzed by chi-square test. In addition, a representative case reconstructing mandible with vascularized fibula flap under general anesthesia was reported. And cases reported before were reviewed. The incidence of the dysplasia and malignant transformation of OKC, which are highly associated with the clinical features of swelling and chronic inflammation, is about 2.76%. But the relevance between the dysplasia and malignant transformation and age, gender together with pain is not statistically high. All in all, the clinical features of swelling and chronic inflammation can be considered as characteristics of the dysplasia and malignant transformation of OKC. Although the pain isn't statistically relevant, it may be a dangerous clew. Also, combined with earlier literatures, the dysplasia and malignant transformation of OKC shows unique features of radiographs and histopathology.

Cystic Lesions of the Jaws: The Top 10 Differential Diagnoses to Ponder.

BACKGROUND: Cystic lesions of the gnathic bones present challenges in differential diagnosis. This category includes a smorgasbord of odontogenic and non-odontogenic entities that may be reactive or neoplastic in nature. While most cystic jaw lesions are benign, variability in biologic behavior makes distinction between these entities absolutely crucial. METHODS: Review. RESULTS: Two clinical cases are presented in parallel and are followed by an illustrated discussion of the ten most likely differential diagnoses that should be considered when confronted with a cystic jaw lesion. Strong emphasis is placed on the histologic differences between these entities, empowering readers to diagnose them with confidence. Perhaps even more importantly, the more common diagnostic pitfalls in gnathic pathology are discussed, recognizing that a definitive diagnosis cannot be rendered in every situation. The histologic diagnoses for the two clinical cases are finally revealed. CONCLUSION: Cystic lesions of the maxilla and mandible may be odontogenic or non-odontogenic. The most common cystic lesions are the reactive periapical cyst, and the dentigerous cyst (which is developmental in nature). It is important to note that cystic neoplasms also occur in the jaws, and that the presence of inflammation may obscure the diagnostic histologic features of lesions like odontogenic keratocyst and unicystic ameloblastoma. Ancillary testing is of limited diagnostic value in most scenarios. However, both clinical and radiographic information (such as the location, size, duration, associated symptoms, and morphology of the lesion in its natural habitat) are significantly useful.

Different presentations of the Buccal Bifurcation Cyst: A case series.

The buccal bifurcation cyst (BBC) is an uncommon odontogenic inflammatory cyst affecting the vestibular aspects of the first or second mandibular molar of pediatric patients. Its etiopathogenesis is not fully understood, but it is hypothesized that food and detritus impacting buccal periodontal pockets in titled tooth would be responsible for inflammation of the pericoronal tissues, leading to proliferation of epithelial rests and subsequent cystic formation. The true prevalence of the BBC is not known, but it is estimated to be less than 1% of all the inflammatory cysts. Most cases are unilateral but bilateral cases may account for up to 30% of all BBCs, which can generate confusion to unfamiliar clinicians. Maxillary cases are extremely uncommon, and to our knowledge, there are no cases published in the English literature. In this case series, we present five BBC cases; two unilateral, two bilateral, and one affecting the maxilla. We included clinical, imaging, and histopathological information to highlight the different presentations that this cyst might have, with the final aim to aid clinicians in its diagnosis and ultimately, its treatment.

Histopathological and histomorphometric analysis of glandular odontogenic cyst-A diagnostic aid.

OBJECTIVES: Compare recognized microscopic parameters, including variations in width, plaque-like thickenings, intra-epithelial microcysts, clefts, mucous, hob-nail, ciliated and clear cells, between glandular odontogenic cyst (GOC) and GOC-like cysts, investigate the extent of cyst circumference exhibiting these features, and inflammation. MATERIALS AND METHODS: Archival records of cysts with histological features of GOC evaluated between 2000 and2020 were retrieved. Slides were revised, and the expression of features throughout the cyst wall was analyzed. Cysts with at least 5 features were classified as GOC, cysts with 3-4 features as GOC-like. RESULTS: The study included 74 cysts, 47 males M, 25 females (2 unknown gender), aged 19-81 years, 62 (83.8%) GOC, 12 (16.2%) GOC-like. Mandible was involved in 44 (59.5%), maxilla in 30 (40.5%), 18 (25%) were associated with unerupted teeth. Cyst classified as GOC had significantly higher rates of all parameters investigated, (except ciliated and clear cells), than GOC-like cysts (p ≤ 0.05). 26 (40.6%) cases showed GOC features in >50% of cyst circumference, 21 (32.8%) involved 25-50%, 17 (26.6%) <25%. More than 50% circumference involvement was highly and independently predictive for a diagnosis of GOC, <25% was highly and independently predictive for GOC-like (p = 0.003). Hobnail cells (p = 0.008) and plaque-like thickenings (p = 0.038) were significantly more frequent in inflamed cysts. CONCLUSION: Besides the number and type of histological features, GOC can be characterized by their distribution within the cyst circumference (focal Vs diffuse), and it may serve as a new diagnostic aid. It is suggested that GOC and GOC-like may represent a single spectrum.

The extra-osseous odontogenic keratocyst: An anachronism?

INTRODUCTION: The aim of this study was to review the literature on extra-osseous odontogenic keratocysts, and to present the best possible approach to these lesions. MATERIAL AND METHODS: A comprehensive literature search was performed using the strategy: (keratocyst) and (soft tissue)). A total of 25 articles were included, 20 reported on extra-osseous odontogenic keratocysts in the soft tissues of the mouth and 17 presented as gingiva cysts. DISCUSSION: Almost all articles were published in the last 20 years and 16 even in the last 10 years. Extra-osseus odontogenic keratocysts are usually found in the cheek or present as gingiva cysts of adults. Muscle abutment of the cheek lesions is common but infiltration of muscles has also been reported. CONCLUSION: In almost none of the reported cases was a preoperative diagnosis available. Based on the clinical presentation and available laboratory tests it is suggested to always do an aspiration biopsy to ascertain the diagnosis preoperatively. This is particularly relevant for those who appear in the soft tissues of the mouth.

Characterization and Classification of Keratinized Odontogenic Cysts in 29 Dogs.

This retrospective case series presents a unique group of odontogenic cysts that are lined by heavily keratinized epithelium and contain laminated keratin. Keratinized odontogenic cyst (KOC) is proposed as appropriate terminology for the described lesions. The series evaluates cysts from 29 dogs, including clinical presentation, diagnostic imaging, and histopathology. All 29 lesions occurred in tooth bearing regions of the jaws; 21 were maxillary and 8 were mandibular. These keratinized odontogenic cysts were unilocular or multilocular, and some demonstrated considerable expansion resulting in bone destruction. In 13 of 29 cases, there was evidence of tooth displacement associated with the expansion of the KOC. The KOCs did not have a distinctive radiographic appearance. 48% of the cysts had a soft tissue defect through which the keratin contents could be visualized. Cyst contents ranged from hard mineralized keratin to fluid consistency with soft flecks of keratin. The pathoetiology of KOCs is unknown; however, the biological behavior is benign and thought to be slowly progressive despite potential for locally destructive growth. Recurrence is uncommon when cyst enucleation and debridement are aggressive or when solid cysts are excised en bloc.

Surgical enucleation of radicular cyst in endodontically treated primary mandibular molar.

Radicular cysts are most common odontogenic cysts seen in the orofacial region, but not commonly detected in paediatric cases. This case report describes the accidental detection of radicular cyst and its surgical management in an 8-year-old boy in lower left back region of the jaw. The article also gives an insight about radicular cyst from its aetiology to the various other treatment modalities.

Imaging of odontogenic keratocysts: a pictorial review.

INTRODUCTION: The aim of the present article was to review and depict the main radiological features of odontogenic keratocysts (OKCs), thus helping the differential diagnoses from other odontogenic cysts and neoplasms. EVIDENCE ACQUISITION: A review of articles published between January 2000 and October 2020 using Medline and the MeSH Term "odontogenic keratocyst" in combination with the following terms "imaging," "radiology," "panoramic radiograph," and "computed tomography," was performed. EVIDENCE SYNTHESIS: Radiographically, OKCs are well-defined unilocular or multilocular radiolucencies bounded by corticated margins. Most lesions are unilocular; instead, multilocular OKCs represent about the 30% of cases, mainly involving the posterior mandible. When, particularly in large lesions, OKCs display a multilocular presentation with adjacent satellite cysts (daughter cysts) a "soap-bubble appearance" can be recognized. DISCUSSION: Panoramic radiograph and CT still play an important role in the diagnosis and treatment planning of OKCs. Unfortunately, it may not be easy to differentiate OKCs from other odontogenic lesions, especially when they are small and unilocular. CONCLUSIONS: Histopathological findings are still necessary to obtain a definitive diagnosis.

Unicystic Ameloblastoma of Mandible: A Case Report.

Ameloblastomas of jaws are benign odontogenic tumors of epithelial origin with four clinical variants: solid multicystic type, unicystic type, desmoplastic type, and extraosseous type. The incidence rate of ameloblastoma is 0.92 per million person-years. Unicystic ameloblastoma refers to those cystic lesions that show clinical and radiologic characteristics of an odontogenic cyst but shows a typical ameloblastomatous epithelium lining part of the cyst cavity, with or without luminal and/or mural tumor proliferation on histological examination. Here is a unique case of unicystic ameloblastoma involving the mandible in a 70-year-old patient. The case was managed by segmental mandibulectomy and flap repair. Unicystic ameloblastoma accounts for only 13% of all known cases in scientific literature. Considering the rarity of the lesion, the purpose of presenting this report on a clinical case is to emphasize the importance of radiological evaluation and histopathological examination for the diagnosis of ameloblastoma. Keywords: ameloblastoma; odontogenic cysts; odontogenic tumors; segmental mandibulectomy.

Peripheral odontogenic keratocysts in buccal soft tissues: two cases report.

Peripheral odontogenic keratocysts are rarely observed, and cases of odontogenic keratocysts of buccal soft tissues are even rarer. This study was performed to present two rare cases of odontogenic keratocysts in buccal soft tissues and review related literature.

Comparing the efficacy of sinus irrigation with traditional Caldwell-Luc procedure following odontogenic cyst surgery involving the maxillary sinus.

A large maxillary odontogenic cyst could intrude into the maxillary sinus. The traditional approach following surgery for such a cyst is the Caldwell-Luc procedure. However, the traditional CDL procedure is associated with more complications and damage of the sinus mucosa. The purpose of this study was to assess a new method with easier operation, which not only prevented postoperative infection but also caused less damage to the maxillary sinus mucosa. A large odontogenic cyst in the maxillary sinus of 40 patients was diagnosed through radiographic imaging and postoperative histopathology. Twenty patients were treated with maxillary sinus saline irrigation after surgery, while 20 patients underwent the traditional Caldwell-Luc procedure. The therapeutic efficacy was evaluated by clinical examination and radiographic imaging; the longest follow-up was 36 months. The postoperative reaction was evaluated. There was a statistically significant difference in facial swelling, visual analog scale (VAS) and temperature elevation between the 2 groups. Sinus irrigation following large odontogenic cyst surgery involving the maxillary sinus can serve as an alternative to standard CDL and has the advantages of fewer complications, reduced trauma, restoration of the mucosa and more satisfactory results.

Central mucoepidermoid carcinoma arising directly from a glandular odontogenic cyst of the mandible: a case report.

BACKGROUND: Central mucoepidermoid carcinoma (MEC) is a rare salivary gland tumor that affects the jawbone. Glandular odontogenic cyst (GOC) is also a rare odontogenic developmental cyst with glandular differentiation. GOC shares some histological features with central MEC, and a pre-existing GOC can develop into central MEC. Here, we present a rare case of central MEC developed directly from a pre-existing GOC of the mandible. CASE PRESENTATION: A 67-year-old Japanese man presented with a cystic lesion in the right third molar region. Histologically, the biopsy specimen demonstrated both typical findings of a GOC component lined with non-keratinized squamous epithelium and a recognizable component of central MEC consisting of polycystic nests with mucous cells, intermediate cells, and epidermoid cells in the cyst wall. The results from the immunohistochemistry for cytokeratin (CK) profiling demonstrated that, while both central MEC and GOC expressed CKs 7, 14, 18, and 19, CK13 was interestingly exclusively expressed in GOC. Fluorescence in-situ hybridization (FISH) revealed the rearrangement of the Mastermind like (MAML)-2 gene in both the MEC and GOC components. CONCLUSIONS: Our case suggests that central MEC and GOC may be in the same spectrum of diseases caused by the rearrangement of the MAML-2 gene. However, given that the expression profile of CK13 was completely different between central MEC and GOC, they can be considered as separate tumors. Overall, we demonstrated a rare case in which central MEC may have originated directly from the GOC.

Odontogenic keratocysts are an important clue for diagnosing basal cell nevus syndrome.

Basal cell nevus syndrome (BCNS) is an autosomal dominant skin disorder characterized by multiple basal cell nevi. Patients with BCNS tend to develop basal cell carcinoma (BCC) and frequently show skeletal abnormalities. Most cases of BCNS are caused by mutations in patched 1 (PTCH1). PTCH1 encodes a transmembrane receptor protein for the secreted molecule sonic hedgehog, which plays a key role in the development of animals ranging from insects to mammals. We analyzed two Japanese BCNS patients from two independent families. Both of our patients had multiple jaw keratocysts. In one patient, these were the key to noticing his BCNS, as he had no skin tumors. The early detection of PTCH1 mutations would enable BCNS patients to be carefully followed up for the occurrence of BCC. The diagnosis of BCC at the early stage leads to prompt surgical treatments, resulting in a good prognosis. The present cases suggest that keratocysts of the jaw might be an important clue for diagnosing BCNS.

Cell Block and Its Impact in the Diagnosis of Jaw Lesions over Fine Needle Aspiration Cytology.

OBJECTIVES: To determine the role and efficacy of fine needle aspiration cytology (FNAC) and cell block in diagnosis of jaw lesions and compare the agreement between FNAC and cell block to predict the diagnosis. METHOD: The sample comprised 51 cases, including 12 odontogenic keratocysts (OKCs), 8 ameloblastomas, 22 radicular cysts, 7 dentigerous cysts, and 1 each of intraosseous mucoepidermoid carcinoma (MEC) and adenomatoid odontogenic tumor (AOT). FNAC samples remaining after hematoxylin and eosin (H&E)-stained cytosmear diagnosis were centrifuged at 3,000 rpm for 10 min. The supernatant was discarded and sediment mixed with 2-3 mL alcohol and filtered. To this, 10% formalin was added, filtered, taken for routine processing, and stained with H&E. The result of FNAC smear and cell block was compared with histopathological diagnosis. RESULTS: On cytological examination of the smears, 7 OKCs and 22 radicular cysts were diagnosed, whereas ameloblastomas, AOT, intraosseous MEC, and dentigerous cysts were not. This gave an agreement of 56.8% with the biopsy reports. Cell block sections stained with H&E of 12 OKCs, 22 radicular cysts, 1 MEC, and 3 cases of ameloblastoma offered a diagnosis in accordance with the biopsies giving an agreement of 74.5%, while dentigerous cyst and AOT failed to do so. In comparison with FNAC, additionally 5 cases of OKC and 1 of MEC could be detected, and in ameloblastoma, out of 8 cases, only 3 yielded a concordant diagnosis through the cell block technique. CONCLUSION: In comparison with FNAC, the architectural pattern and the morphology of the cells were better preserved by the cell block technique. This substantiates that cell block could be used as an ancillary technique to aid in definitive diagnosis of head and neck swellings.

Nine cases of soft tissue keratocysts arising from buccal mucosa and lateral fascial deep region: Clinicopathological and immunohistochemical study.

BACKGROUND: Soft tissue keratocysts (SKC) are extremely rare and show similar microscopic morphology to keratocystic odontogenic tumor. The aim was to investigate immunohistochemical (IHC) features and origin of SKCs developing in buccal mucosa and lateral facial deep region. MATERIAL AND METHODS: Expression of CK19, CK10/13, Ki67, Cyclin D1 and Osteopontin (OPN) of 9 SKCS were investigated using IHC. Forty different types of cysts in jaw/soft tissue were used as control. Follow-up was performed. RESULTS: CK10/13 positivity occurred more frequently and intensely in SKC and intraosseous parakeratinized odontogenic keratocysts (COKC). However, OPN positivity was observed only in COKC. CONCLUSION: This is the largest case series of SKCs; along with first attempt to investigate the expression of OPN on SKC. Given the microscopic and immunohistochemical features, we prefer the view that SKC is odontogenic origin but represents the soft tissue counterpart of COKC, since their expressions of OPN were extremely different.