METHODS: A literature review was conducted using the keyword of "Odontogenic carcinosarcoma" and all relevant articles were screened. The data collected include demographic profile (age, gender), clinical information (symptoms, location, size), radiologic features, histopathological examination, management, recurrence, metastases, and survival status.

RESULTS: A total of 17 OCS cases including a new case from our hospital. The incidence of OCS was highest in the third decades of life with predilection for male and posterior region of mandible. Clinically, patients may present with swelling and neurological symptoms. Radiographic examination often showed radiolucency with ill-defined border. This tumour demonstrates an aggressive behaviour with reported cases of distant metastases to the lung, lymph nodes, rib, and pelvis. Here, we report an interesting case of OCS in a 38-year-old man with a previous diagnosis of ameloblastoma. The patient was diagnosed with ameloblastoma but refused surgical intervention and returned after 10 years with rapidly enlarging mass on the right side of mandible. Microscopically, the lesion appears as biphasic odontogenic tumour with malignant cytological features seen in both epithelium and mesenchymal components. The spindle to round mesenchymal tumour cells were only positive for vimentin. Ki67 proliferation index was high in both epithelium and mesenchymal components.

METHODS: We document a case of EBV-SMT in an HIV-positive 25-year-old man. The lesion was incised and assessed histologically and a panel of immune markers were performed. EBV association was demonstrated by in situ hybridization for EBV-encoded RNA (EBER-ISH).

RESULTS: Microscopically, the tumor composed of mildly pleomorphic, ovoid to spindled cells with numerous slit-like vascular channels. The tumor cells exhibited diffuse and strong immunoreactivity for smooth muscle actin (SMA) and focal positivity for h-caldesmon. EBER-ISH of the tumor cells revealed strong positive nuclear signals.

METHODS: We retrieved 4 previously reported SMCA, performed additional immunohistochemical and targeted next-generation sequencing (NGS). We also investigated the use of NKX3.1 as a marker for SMCA in the context of its prevalence and extent (using H-score) in a mixed cohort of retrospectively and prospectively tested head and neck lesions (n = 223) and non-neoplastic tissues (n = 66).

RESULTS: NKX3.1 positivity was confirmed in normal mucous acini as well as in mucous acinar class of lesions (5/6, mean H-score: 136.7), including mucinous adenocarcinomas (3/4), SG-IPMN (1/1), and microsecretory adenocarcinoma (MSA) (1/1). All SMCA were positive. Fluorescence in situ hybridization for SS18 rearrangements were negative in all successfully tested cases (0/3). NGS was successful in two cases (cases 3 and 4). Case 3 demonstrated a PTEN c.655C>T p.Q219* mutation and a SEC16A::NOTCH1 fusion while case 4 (clinically aggressive) showed a PTEN c.1026+1G>A p.K342 splice site variant, aTP53 c.524G>A p.R175H mutation and a higher tumor mutation burden (29 per Mb). PTEN immunohistochemical loss was confirmed in both cases and a subset of tumor cells showed strong (extreme) staining for P53 in Case 4.

METHOD: An electronic search to collate all the information on studies on homeobox gene expression in odontogenic lesions was carried out in four databases (PubMed, EBSCO host, Web of Science and Cochrane Library) with selected keywords. All papers which reported expression of homeobox genes in odontogenic lesions were considered.

RESULTS: A total of eleven (11) papers describing expression of homeobox genes in odontogenic lesions were identified. Methods of studies included next generation sequencing, microarray analysis, RT-PCR, Western blotting, in situ hybridization, and immunohistochemistry. The homeobox reported in odontogenic lesions includes LHX8 and DLX3 in odontoma; PITX2, MSX1, MSX2, DLX, DLX2, DLX3, DLX4, DLX5, DLX6, ISL1, OCT4 and HOX C in ameloblastoma; OCT4 in adenomatoid odontogenic tumour; PITX2 and MSX2 in primordial odontogenic tumour; PAX9 and BARX1 in odontogenic keratocyst; PITX2, ZEB1 and MEIS2 in ameloblastic carcinoma while there is absence of DLX2, DLX3 and MSX2 in clear cell odontogenic carcinoma.

STUDY DESIGN: A retrospective analysis was conducted on 371 cases at a Nigerian university hospital between 2000 and 2023. Age, gender, site, histological variants, tumor size and duration were analyzed. Statistical analyses included the Shapiro-Wilk test, Mann-Whitney U test, Chi-square test, and Spearman rank correlation analysis.

RESULTS: The median patient age was 30 years (mean age 32.2), with a male-to-female ratio of 1.12:1. 54.7% of cases occurred in young adults (age range 20-39 years). Among the lesions, 11.3% were in the maxilla and 88.7% in the mandible. Patients with mandibular lesions had a median age of 29 years, while those with maxillary lesions had a statistically significantly higher median age of 37.5 years p-value = 0.001. Median tumor size was 36 cm2 for the mandible and 24 cm2 for the maxilla (significant p-value of 0.002). There was no correlation between tumor size, age, or gender. However, there was a significant correlation between tumor size and the duration of the condition.

STUDY DESIGN: An observational study was conducted among 54 patients who reported to the outpatient department of Saveetha Dental College and Hospitals. The patients were divided into three groups: Group I healthy individuals (n = 18), Group II: case group (leukoplakia, OSMF, and leukoplakia and OSMF) (n = 18), and Group III: OSCC (n = 18). Real-time polymerase chain reaction analysis was carried out to assess the expression profiles of miRNA 21, miRNA 184, and miRNA 145. The statistical analysis was calculated using SPSS software version 23.