Early clinical diagnosis of synchronous multiple primary lung cancer.

The diagnosis of synchronous multiple primary lung cancer (SMPLC) remains a formidable challenge. The aim of the present study was to identify useful clues for the clinical diagnosis of SMPLC, in particular for the early stages. The medical records of 10 patients diagnosed with SMPLC with different histological types were analyzed retrospectively. Chest computed tomography (CT) findings showed two pulmonary lesions in all patients. The two lesions displayed malignant characteristics of primary lung cancer. The levels of a number of tumor markers, including carcinoembryonic antigen, neuron-specific enolase, cytokeratin fragment 21-1, squamous cell carcinoma and CA125 increased in 2 patients. Auxiliary examinations of other physical sites in these patients did not show signs of neoplasm metastasis. Two tumors were separately staged and appropriate treatment was carried out based on the revised stage, which provided more benefits for SMPLC patients. The diagnosis of SMPLC might be delayed or mistaken owing to its similarity to neoplasm metastasis. A high index of awareness is required for the early diagnosis of this disease. The malignant characteristics of primary lung cancer in various lesions may be valuable clues for the diagnosis of SMPLC. Alterations in the levels of tumor markers may be a poor diagnostic tool for the detection of SMPLC. Separate biopsies for different pulmonary masses should be performed for clinical staging as soon as possible and reasonable treatment based on the stage should also be selected.