Oral squamous cell carcinoma of the tongue dorsum with multiple cancer-associated mutations in the TP53 gene.

OBJECTIVES: Squamous cell carcinoma (SCC) of the tongue is one of the most common oral cancers, tongue dorsum being a site of low incidence of primary SCC. We report a rare case of SCC of the tongue dorsum in a 69-year-old man having a history of multiple cancers, including esophageal cancer, gastric cancer, and renal cell carcinoma. We discuss the findings in relation to past reports. MATERIALS AND METHODS: TP53 was PCR amplified using the genomic DNA extracted from peripheral blood mononuclear cells and formalin-fixed, paraffin-embedded tissue sections from the tumor site of the patient, and was sequenced. RESULTS: Physical examination revealed an elastic hard mass on the tongue dorsum, with a size of 22 x 15 mm. There were no palpable enlarged lymph nodes in the cervical and submandibular region. An incisional biopsy was performed. The diagnosis was well-differentiated SCC of tongue, T2N0M0, Stage II, and was treated through surgery. Surgical specimen of the deep ulcer area showed increased expression of p16 protein with no expression of p53 protein. He had a heterozygous gene polymorphism (c.215C > G: p.Pro72Arg) and a germline mutation (c.838A > T: p.Arg280*) of the TP53. However, there has been no recurrence or metastasis of the tongue carcinoma through the follow-up for 3 years. CONCLUSION: Germline TP53 mutation and codon 72 polymorphism are risk factors for uncontrolled cell proliferation, possibly leading to the patient's clinical phenotype. Therefore, strict follow-up is required when treating those who are at a higher risk of cancer due to a TP53 mutation.