A large-cohort study of 2971 cases of epulis: focusing on risk factors associated with recurrence.

BACKGROUND: To analyze the clinicopathological features of different histological subtypes of epulis, and evaluate the risk factors associated with recurrence. MATERIALS AND METHODS: A retrospective study including 2971 patients was performed. The patients' sex, age, location, size, histological subtypes, recurrence information, oral hygiene habits, periodontitis symptoms and smoking history were retrieved from the patient medical records and follow-up information. RESULTS: Among the 2971 cases, focal fibrous hyperplasia (FFH) was the most common lesion (60.92%), followed by peripheral ossifying fibroma (POF) (29.32%), pyogenic granuloma (PG) (8.08%) and peripheral giant cell granuloma (PGCG) (1.68%). The peak incidence of epulis was in the third and fourth decade of life, with a mean age of 45.55 years. Female predominance was found in all types of lesions with a female to male ratio of 1.71:1. PG had the highest recurrence rate (17.18%), followed by POF (12.98%), FFH (9.55%) and PGCG (8.82%). Histological subtypes were significantly correlated with the recurrence of epulis (P = 0.013). Regular supportive periodontal therapy (P = 0.050) had a negative correlation with recurrence, whereas symptoms of periodontitis (P < 0.001) had a positive correlation with the recurrence of epulis. CONCLUSIONS: Controlling the periodontal inflammation and regular supportive periodontal therapy might help reduce the recurrence of epulis.

Ameloblastoma with mucous cells: A clinicopathological, BRAF mutation, and MAML2 rearrangement study.

OBJECTIVES: To investigate the clinicopathological features, BRAF V600E mutation, and MAML2 rearrangement of ameloblastoma with mucous cell differentiation. MATERIALS AND METHODS: Five cases of ameloblastoma with mucous cell differentiation were retrospectively studied. Clinicopathological features, BRAF V600E mutation, and MAML2 rearrangement were analyzed. Follow-up information was available for all cases. RESULTS: Of five cases, two cases were male and three were female, aged 18-55 years. Four cases were located in the mandible and one case in the maxilla. Histologically, four of the five cases (80%) presented with cystic features and three of the five cases (60%) with varying degrees of squamous metaplasia. The mucous cells were located in the epithelial islands or the luminal aspect of the cystic cavities. The BRAF V600E mutation was found in three of five cases (60%). All the cases showed no MAML2 rearrangement. Two cases were recurrent lesions, and one case had a local recurrence during the follow-up. CONCLUSIONS: Ameloblastoma with mucous cell differentiation is closely related to the cystic features, squamous metaplasia, and shows a high prevalence of BRAF V600E mutation. The absence of MAML2 rearrangement reveals that ameloblastoma with mucous cell differentiation and central mucoepidermoid carcinoma (MEC) are two distinct tumor entities.

Orthokeratinized odontogenic cyst (OOC): Clinicopathological and radiological features of a series of 48 cases.

OBJECTIVES: To demonstrate the clinicopathological and radiological features of orthokeratinized odontogenic cysts (OOCs), and analyze the epithelial cell proliferative activity between OOCs and odontogenic keratocysts (OKCs). MATERIALS AND METHODS: Clinicopathological and radiological analyses were performed in all OOC cases. The expression of cell proliferation markers, Ki-67 and cyclin D1, was detected by immunohistochemistry. RESULTS: A total of 48 OOC patients, 28 males and 20 females, were included. The mean age was 33.50 years, with a range of 13-61 years. The mandible was affected five times as frequently as the maxilla (mandible 40, maxilla 8). All OOCs were unilocular radiolucencies with well-defined margins, and 30 of 36 showed loss of continuity of the buccal or lingual cortices based on computed tomography (CT) images. Three cases exhibited root resorption; tooth displacement occurred in 4 cases. The average volume of the cysts on CT was 7794.25 ± 6952.98 mm3. All cysts were treated by enucleation or enucleation after decompression. The average follow-up time was 32.50 ± 27.58 months (ranging from 6 to 65 months), and the overall recurrence rate was 4.44% (2 of 45). Compared with OKCs, Ki-67 and cyclin D1 expression were significantly lower in OOCs (P < 0.001). CONCLUSIONS: OOCs occur more frequently in mandible with a slight male predilection and have a lower proliferative activity than OKCs. Radiologically, OOCs are more likely associated with buccolingual expansion and destruction of cortical bone. Due to the lower aggressiveness and recurrence rate, enucleation or decompression combined with enucleation is the first treatment choice for OOC.

Melanotic Neuroectodermal Tumor of Infancy: A Clinicopathological and BRAF V600E Mutation Study of 11 Cases.

PURPOSE: To investigate the clinicopathological features and BRAF V600E mutation of melanotic neuroectodermal tumor of infancy (MNTI). MATERIALS AND METHODS: Eleven cases of MNTI diagnosed at the Department of Oral Pathology were collected. Clinicopathological characteristics were obtained from the medical records. Immunostaining was performed by immunohistochemistry (IHC). Amplification-Refractory Mutation System-qPCR (ARMS-qPCR) and Sanger Sequencing were used to detect BRAF V600E mutation. RESULTS: Of the 11 cases, 3 cases were female and 8 cases were male. The mean age of the first symptoms was 3.2 months (range: 1 to 6 months). Ten cases (90.9%) located in maxilla but only one (9.1%) in mandible. Most of the cases demonstrated well-defined mass with lytic bone destruction and tooth germ affecting radiologically. Histologically, MNTI was consisted of large polygonal melanin-producing epithelioid cells and small round neuroblast-like cells which arranged in irregular alveolar, tubuloglandular and fissured architecture. The epithelioid cells expressed Vim, Pan-CK, NSE and HMB45, while the smalls cells expressed Syn, NSE and scattered Vim. Most cases showed low Ki-67 index (range: <1% to 50%). None of the MNTI cases showed BRAF V600E mutation. Most cases were treated with enucleation (45.4%) or curettage (36.4%). Among the 11 cases, 6 cases had follow-up information, and 2 cases had recurrence lesions after surgery. CONCLUSION: MNTI, an extremely rare tumor, mainly affects male infants with strong preference for maxilla. Distinct histopathological features and immunohistochemical profile are helpful to distinguish from other melanin-containing tumors and small round cell tumors. No BRAF V600E mutation in MNTI is detected in the present study and needs further investigations. The factors that contribute to the local recurrence of MNTI are controversial, but the close follow-up for the patients is recommended.

Modification of the anterior-posterior tongue rotation flap for oral tongue reconstruction.

The aim of this study is to evaluate the efficacy and long-term outcome of a modification of the anterior-posterior tongue rotation flap used for reconstruction of tongue following cancer ablation. From April 2016 to September 2017, 21 consecutive patients with tumor classification (T2), lymph node classification (N0) tongue cancer on the anterior and middle one-third portion were selected for this study. A modification of the anterior-posterior tongue rotation flap was selected for tongue reconstruction after the cancer resection. Patient's scorings of swallowing, chewing, speech and taste were recorded. Patient after tongue flap reconstruction acquired satisfied tongue movement that allows normal functional outcomes for swallowing, chewing, speech and taste. Local tumor recurrence was not observed during the follow-up examination (range, 12-24 months). The modification of the anterior-posterior tongue rotation flap was a safe and reliable treatment for medium-size tongue cancer (T2N0), especially suitable to patients who cannot endure prolonged surgery.

Primary pseudomyogenic hemangioendothelioma of right maxilla: a case with immunohistochemistry and FOSB rearrangement study.

OBJECTIVE: Primary pseudomyogenic hemangioendothelioma (PMH) of bone is an extremely rare vascular neoplasm. We present here a case of primary PMH occurring in the maxilla. STUDY DESIGN: A 34-year-old man was referred to our hospital for treatment because of possible recurrence after surgery and chemotherapy of a right maxillary malignant tumor. Morphologic features, immunophenotypes, and FOSB gene rearrangement status of the surgically sectioned sample were assessed by hematoxylin-eosin staining, immunohistochemistry, and fluorescence in situ hybridization, respectively. RESULTS: Morphologically, the tumor cells were arranged in a loose fascicular and sheet-like manner, with a large number of reactive woven bones forming. The most striking feature was the presence of epithelioid cells with abundant brightly eosinophilic cytoplasm, which resembled the rhabdomyoblast in appearance. The tumor was diffusely positive for AE1/AE3, CD31, erythroblast transformation-specific transcription factor, and Friend leukemia integration 1; negative for CD34, CAM5.2, epithelial membrane antigen, and desmin; and had retained expression of integrase interactor 1. The tumor harbored FOSB rearrangement. No distant metastasis was found during the follow-up period (18 months). CONCLUSIONS: To the best of our knowledge, this case represents the first report of PMH arising in the maxilla. The distinct morphologic features, immunophenotypes, and FOSB rearrangement could help achieve precise diagnosis and prevent misdiagnosis of mimics with overlapping features.

[Construction of clinical practice system of oral pathology for long-term program students in stomatology].

PURPOSE: To construct clinical practice system, making up for the shortcomings in the instructional framework of oral histology and pathology, promoting the integration of theory and clinical practice, and enhancing teaching quality of long-term students of stomatology. METHODS: Laying down clinical practice plans and formulating technical operation criteria for pathological experiments, constructing a complete database and training high-level teachers, and evaluating through the following three aspects: practice assessment, teacher-student symposium and questionnaire survey. RESULTS: After completing the clinical practice, the students got the average score of 89.37. In questionnaire survey, the students generally expressed that they had a better understanding of the specialized characteristics and routine skills of the speciality, and improved their practical ability, thus stimulating their interest in self-directed learning. CONCLUSIONS: The construction and practice of clinical practice system of oral histology and pathology can effectively improve the educational objectives and teaching quality of this discipline, which will play a positive role in scientific research and future medical work of long-term students majoring in stomatology.