Tehran University Medical Journal

Background: Head and neck squamous cell carcinoma (HNSCC) is the malignancy of squamous cells (the epidermal layer of skin) in cavities in head and neck includes: larynx, pharynx, paranasal sinuses and oral cavity. The main goal of this research was to understand the effect of mutations in two important genes (KRAS and BRAF) in RAS/MAP kinase (EGFR) signaling pathway in tumor cells with head and neck squamous cell carcinoma in Iran.
Methods: The present cross-sectional study performed from October 2015 to September 2016 on 40 patients suffering from head and neck squamous cell carcinoma, all confirmed by pathology department of Imam Khomeini hospital. Tumor samples were achieved from the surgical cancer department of Imam Khomeini hospital and stored in liquid nitrogen until starting tests. The tests done in genetic laboratory of Tehran University of Medical Sciences. Techniques we used in this research, were DNA extraction based on phenol-chloroform approach, Multiplex PCR (M-PCR) to amplify mentioned exons and KRAS/BRAF strip assays to detect mutations in mutated hotspots in exon 2 of KRAS and codon V600E in BRAF gene.
Results: In this study, we observed 7 mutations in codons 12 and 13 exon 2 in KRAS gene (about 17.5%) and 4 mutations in codon V600E in BRAF gene (about 10%) of obtained tumor samples. The hotspot mutation in codon 12 were Asp (10%) and Ser (5%) respectively. In BRAF, the most common mutation, as we expected according to other researches, was observed in codon V600E. We also observed that 29 people of these patients were male (about 72.5%) and 11 patients were female (about 27.5%). Moreover, 28 patients were over 50 years, while 7 patients were below the age of 50.
Conclusion: The results of this study showed that mutations in genes KRAS and BRAF especially in studied hotspots, and the effects on their molecules in EGFR signaling pathway are important in involving head and neck squamous cell carcinoma, as other cancers. These findings may be considered in choosing drugs for targeted chemotherapy.

Background: Primary intraosseous squamous cell carcinoma (PIOC) of the mouth is a very rare but well-known carcinoma. It is locally invasive and its prognosis is quite poor. It may originate from the walls of an odontogenic cyst or de novo from the remnant epithelium at this region. Because the early symptoms of such malignancies are sometimes similar to those of inflammatory or periodontal diseases, early diagnosis is the most important step toward appropriate treatment.
Case Presentation: The case was a 46-year-old female with a sudden luxation of two posterior mandibular molars referred to a general dentist in May 2019. With diagnosis of periodontitis, the teeth were extracted without finding the cause of the tooth luxation. After four months, because of pain, swelling and non-healing socket of extracted teeth she referred to the department of Oral medicine in Mashhad Faculty of Dentistry. The patient was healthy with no systemic disease, drug history or familial history of cancer and no history of trauma, habits, tobacco, alcohol, and smoking. ln clinical examination, a nodular swelling with extensive ulcer and rolled borders along with hyperkeratosis and erythema on the posterior part of the right mandibular ridge was observed. The Extraoral examination revealed a tender mobile lymph node in the right submandibular region. After radiographic evaluation, with an initial diagnosis of SCC originated from the socket of extracted mandibular molars, incisional biopsy was performed, and histopathological analysis of the specimen revealed a primary intraosseous squamous cell carcinoma (grade II) and then necessary treatments (surgery, radiotherapy, chemotherapy) were performed.