Comprehensive Molecular Characterization of Polymorphous Adenocarcinoma, Cribriform Subtype: Identifying Novel Fusions and Fusion Partners.

Polymorphous adenocarcinoma (PAC) is a common, usually low-grade salivary gland carcinoma. While conventional PACs are most associated with PRKD1 p.E710D hotspot mutations, the cribriform subtype is often associated with gene fusions in PRKD1, PRKD2, or PRKD3. These fusions have been primarily identified by fluorescence in situ hybridization (FISH) analysis, with a minority evaluated by next-generation sequencing (NGS). Many of the reported fusions were detected by break-apart FISH probes and therefore have unknown partners or were negative by FISH altogether. In this study, we aimed to further characterize the fusions associated with PAC with NGS. Fifty-four PACs (exclusively cribriform and mixed/intermediate types to enrich the study for fusion-positive cases) were identified and subjected to NGS. Fifty-one cases were successfully sequenced, 28 of which demonstrated gene fusions involving PRKD1, PRKD2, or PRKD3. There were 10 cases with the PRKD1 p.E710D mutation. We identified a diverse group of fusion partners, including 13 novel partners, 3 of which were recurrent. The most common partners for the PRKD genes were ARID1A and ARID1B. The wide variety of involved genes is unlike in other salivary gland malignancies and warrants a broader strategy of sequencing for molecular confirmation for particularly challenging cases, as our NGS study shows.

Pediatric Odontogenic Tumors.

Odontogenic tumors are rare tumors of the jaws that arise from remnants of the tooth forming apparatus. Some odontogenic tumors demonstrate strong predilection for pediatric patients including the unicystic ameloblastoma, adenomatoid odontogenic tumor, ameloblastic fibroma, ameloblastic fibro-odontoma, odontoma, and primordial odontogenic tumor. In this review, we discuss the clinical, radiographic, histopathologic, and molecular characteristics of select odontogenic tumors that demonstrate pediatric predilection and review management.

Pediatric Gnathic Bony and Mesenchymal Tumors.

Evaluation of bone pathology within the head and neck region, particularly the gnathic bonesis is complex, demonstrating unique pathologic processes. In part, this variation is due to odontogenesis and the embryological cells that may be involved, which can contribute to disease development and histologic variability. As with any boney pathosis, the key is to have clinical correlation, particularly with radiographic imaging prior to establishing a definitive diagnosis. This review will cover those entities that have a predilection for the pediatric population, and while it is not all inclusive, it should serve as a foundation for the pathologist who is evaluating bony lesions involving the craniofacial skeleton.

Efficacy and safety of a novel mucoadhesive clobetasol patch for treatment of erosive oral lichen planus: A phase 2 randomized clinical trial.

BACKGROUND: Oral lichen planus (OLP) is a chronic inflammatory disorder of the oral mucosa. Currently there is no approved treatment for OLP. We report on the efficacy and safety of a novel mucoadhesive clobetasol patch (Rivelin® -CLO) for the treatment of OLP. METHODS: Patients with confirmed OLP and measurable symptomatic ulcer(s) participated in a randomized, double-blind, placebo-controlled, multicenter clinical trial testing a novel mucoadhesive clobetasol patch (Rivelin® -CLO) in OLP across Europe, Canada, and the United States. Patients were randomized to placebo (nonmedicated), 1, 5, 20 µg Clobetasol/patch, twice daily, for 4 weeks. The primary endpoint was change in total ulcer area compared to baseline. Secondary endpoints included improvement from baseline in pain, disease activity, and quality of life. RESULTS: Data were analyzed and expressed as mean [SD]. One hundred thirty-eight patients were included in the study; 99 females and 39 males, mean age was 61.1 [11.6] years. Statistical analyses revealed that treatment with 20-µg Rivelin® -CLO patches demonstrated significant improvement with ulcer area (p = 0.047), symptom severity (p = 0.001), disease activity (p = 0.022), pain (p = 0.012), and quality of life (p = 0.003) as compared with placebo. Improvement in OLP symptoms from beginning to the end of the study was reported as very much better (best rating) in the 20-µg group (25/32) patients compared to the placebo group (11/30), (p = 0.012). Adverse events were mild/moderate. Candidiasis incidence was low (2%). CONCLUSIONS: Rivelin® -CLO patches were superior to placebo demonstrating statistically significant, clinically relevant efficacy in objective and subjective improvement and, with a favorable safety profile.

Ectopic teeth with disparate migration: A literature review and new case series.

Purpose: Ectopic eruption can be defined as the emergence of a tooth in an abnormal location, where the tooth does not follow its typical eruption pathway. While ectopic eruption within the dentate region is well-documented in the literature, ectopic eruption in non-dentate regions is relatively rare. This study aimed to report 6 cases of ectopic teeth and present a systematic review of the English-language literature on ectopic teeth, emphasizing demographic characteristics, radiographic features, potential complications, and treatment options. Materials and Methods: A literature search was conducted using the PubMed, Medline, Web of Science, and Cochrane databases. The demographic data and radiographic findings of patients presenting with ectopic teeth were recorded. Results: The literature review yielded 61 cases of ectopic teeth, with patients ranging in age from 3 to 74 years. The findings from these previously reported cases demonstrated that the most common location for ectopic teeth was the maxillary sinus, which is consistent with this case series. The Pearson chi-square test was performed to evaluate the correlation between age and location of ectopic teeth, and the results were found to be statistically significant (P<0.05). However, no statistically significant relationship was observed between sex and the location of ectopic teeth. Conclusion: The distinct features of these cases warrant reporting. This study presents the first case of supernumerary teeth in the condyle without any associated pathosis. Another notable characteristic is the pre-eruptive resorption of 2 inverted supernumerary teeth ectopically located in the palate, which predisposes to sinus opacification.

Cone-beam computed tomographic imaging of central giant cell granuloma: A comprehensive review.

Purpose: The aim of this study was to characterize the cone-beam computed tomographic (CBCT) imaging features of central giant cell granuloma (CGCG) of the jawbone. Materials and Methods: This study retrospectively reviewed 26 CBCT studies of histologically proven cases of CGCG during a period of 20 years, from 1999 to 2019. Patients' demographic data were recorded, and radiographic features were assessed (location, border, cortication, appearance of the internal structure, locularity, septation, expansion, cortical perforation, effects on surrounding tissue, whether the lesion crossed the midline, and lesion volume). Results: In this study, CGCGs were seen almost twice as often in the mandible than in the maxilla, and 64.7% of mandibular lesions involved the anterior region. Only 26.9% of lesions crossed the midline, a feature that was considered characteristic of CGCG. Furthermore, 65.4% of lesions were unilocular and 34.6% were multilocular. The correlation between a lesion's size and its locularity was statistically significant, and larger lesions showed a multilocular appearance. The mean volume of multilocular lesions was greater than that of unilocular lesions. Conclusion: CGCGs showed variable radiographic features on CBCT, and this imaging modality is highly effective at demonstrating the radiographic spectrum and lesional extent of CGCGs in the jawbone.

Enhanced detection of oral dysplasia by structured illumination fluorescence lifetime imaging microscopy.

We demonstrate that structured illumination microscopy has the potential to enhance fluorescence lifetime imaging microscopy (FLIM) as an early detection method for oral squamous cell carcinoma. FLIM can be used to monitor or detect changes in the fluorescence lifetime of metabolic cofactors (e.g. NADH and FAD) associated with the onset of carcinogenesis. However, out of focus fluorescence often interferes with this lifetime measurement. Structured illumination fluorescence lifetime imaging (SI-FLIM) addresses this by providing depth-resolved lifetime measurements, and applied to oral mucosa, can localize the collected signal to the epithelium. In this study, the hamster model of oral carcinogenesis was used to evaluate SI-FLIM in premalignant and malignant oral mucosa. Cheek pouches were imaged in vivo and correlated to histopathological diagnoses. The potential of NADH fluorescence signal and lifetime, as measured by widefield FLIM and SI-FLIM, to differentiate dysplasia (pre-malignancy) from normal tissue was evaluated. ROC analysis was carried out with the task of discriminating between normal tissue and mild dysplasia, when changes in fluorescence characteristics are localized to the epithelium only. The results demonstrate that SI-FLIM (AUC = 0.83) is a significantly better (p-value = 0.031) marker for mild dysplasia when compared to widefield FLIM (AUC = 0.63).

Longitudinal clinicopathologic data of the progression of oral mucosal melanoma-report of 2 cases and literature review.

Oral mucosal melanoma (OMM) is notorious for having a poor prognosis. Recognition of the early features of OMM by both clinicians and pathologists can play an important role in improving survival. Therefore, the purpose of this report is to increase awareness of the early features of OMM, by presenting 2 cases with longitudinal clinical and histopathologic documentation showing progression of OMM from a deceptively bland premalignant (noninvasive) oral melanocytic lesion (POML). By analyzing the clinical and histopathologic features of POML in our cases, and those in the literature, we found that the concerning features are (1) clinically, a pigmented lesion violating the ABCDE criteria or showing multiple recurrences; and (2) histologically, a melanocytic proliferation, in either a lentiginous or pagetoid pattern with or without cellular atypia. Making a diagnosis of POML prospectively is often challenging. Increasing awareness of the clinical and histopathologic features and complete surgical excision of POML are emphasized.