Clinical presentation and treatment of four children with pulmonary mucoepidermoid carcinoma.

Primary lung cancer in childhood is extremely rare, with an incidence rate of less than 2/100,0000, and pulmonary mucoepidermoid carcinoma (PMEC), is even rarer. Their symptoms are usually not specific, and there are no guidelines for their management, which makes their clinical management a challenge for pediatricians. The purpose of this report is to discuss the clinical presentation, positive signs, examinations, pathological characteristics, surgical modalities, chemotherapy regimens, and prognosis in children. The clinical data of four patients diagnosed with PMEC at the Children's Hospital of Chongqing Medical University from June 2021 to November 2022 were retrospectively analyzed, and their clinical features, treatment, and prognosis were summarized. Among them, two were male and two were female; their ages ranged from 3 years and 10 months to 10 years and 11 months, and all were staged according to tumor node metastasis classification (TNM). Immunohistochemical tests were performed in all children, among which four cases were positive for cytokeratin (CK), two cases were positive for CK7, four cases were positive for p63, about 5-10% of tumor cells were positive for Ki67. Among the four children, three had surgery alone and one had surgery + chemotherapy. All four children are presently living, with no evidence of tumor recurrence or metastasis. PMEC in children is very rare, and its age of onset and symptoms are not specific, and there is no obvious correlation with gender. Its diagnosis mainly relies on pathomorphological diagnosis, and immunohistochemical detection has no specific performance. The prognosis of children with PMEC is related to the clinical stage and whether surgery is performed. Whether further chemotherapy or radiotherapy is needed for patients who cannot undergo surgical resection and for those who have a combination of distant metastases requires further clinical studies.