Head and neck squamous cell carcinoma (HNSCC) is the most common type of heterogeneous malignant tumor. Over 60% of HNSCC patients are at locally advanced stage at the time of diagnosis. Despite the emergence of advanced diagnosis and treatment measures, the prognosis of patients with recurrent or metastatic HNSCC remains poor. The Period (PER) gene family is an important member of the circadian clock genes, with family members PER1, PER2, and PER3 showing differential expression in HNSCC, participating in biological processes such as proliferation, apoptosis, invasion, or metastasis of tumor cells. In most studies, they exhibit anti-cancer effects and are closely related to the tumor microenvironment, immunotherapy, chronotherapy, etc., making them potential biomarkers. A comprehensive analysis of the expression of PER gene family in HNSCC, its biological role in the occurrence and development of tumor and the corresponding molecular biological mechanism is helpful to explore its potential application value in the diagnosis and treatment of HNSCC.

Objective To evaluate the value of enhanced CT scan in differential diagnosis of thyroid neoplasm.Methods 27 cases of thyroid neoplasm including 18 cases of thyroid adenoma and 9 cases of thyroid papillary carcinoma proved by operation and pathology were retrospectively analyzed.Results In 18 cases of thyroid adenoma,there were 12 cases with well defined enhanced ring and 6 cases with enhanced nodule in adenoma.In 9 cases of thyroid papillary carcinoma,there were no complete enhanced ring on the wall,and 4 cases with enhanced nodule on the wall,there were 7 cases with fine granular or plague like calcifications and 4 cases with sign of surrounding structures involved.Conclusion In CT diagnosis of thyroid neoplasm,enhanced scan is necessary for characterization of the tumors.Invasion of surrounding structures is a characteristic sign of malignancy.Nodules enhancement of the tumor wall accompanied with granular calcification is the signs of thyroid papillary carcinoma,tumor sharp wall is the sign of adenoma.