A case of synchronous double primary lung cancer with neuroendocrine features

We report a case of unique double primary lung cancers with neuroendocrine features in a 63-year-old male smoker. The mass in the left lower lobe (LLL ) was a small cell/large cell carcinoma with spindle cell sarcomatous areas and organoid structure. The mass in the left upper robe (LUL) was a tubula r adenocarcinoma with neuroendocrine features including organoid nests show ing occasional rosette formation, nuclear palisading in the periphery of th e nests and positive immunoreaction for CD56, chromogranin A and synaptophy sin. The difference in histological structures between the two masses led u s to diagnose double primary lung cancer. The combination of small cell lun g carcinoma and spindle cell carcinoma is very uncommon. The relationship b etween LLL and LUL tumors remains unclear. Multiple lung cancers with neuro endocrine features have only rarely been reported in the literature. The pa tient in our case died of widespread cancer 2 years and 4 months after the surgery without adjuvant chemotherapy, a longer postoperative survival time than in cases of ordinary extensive small cell lung cancer. Multiple lung cancers with neuroendocrine features are extremely rare and similar cases h ave not been reported in the literature. Neuroendocrine differentiation has attracted widespread attention and, therefore, examining neuroendocrine fe atures in lung cancers is important.