Abstract. Pulmonary large-cell neuroendocrine carcinoma (LCNEC) is a rare and malignant form of lung cancer with a poor prognosis for patients. The common sites of metastases are the liver, adrenal glands, bone and brain. LCNEC rarely metastasizes to the small intestine, ovaries, tonsils, mandible, vulva or spine. To the best of our knowledge, there have been no reports of leptomeningeal metastasis of LCNEC to date. The present case report describes an unusual case of leptomeningeal metastasis from pulmonary LCNEC alongside a review of the literature. Biopsies of pulmonary lesions and cervical lymph nodes confirmed the diagnosis of LCNEC in a 39-year-old male patient. At 2 months after chemotherapy, the patient began to experience hoarseness, epileptic seizures and blurred vision. Furthermore, the patient presented with radiating pain and numbness in his lower left limb. Imaging findings and cytological examination of cerebral spinal fluid supported the diagnosis of leptomeningeal metastasis. The patient's neurological symptoms were markedly alleviated following receipt of radiation and intrathecal chemotherapy. The patient survived for 4.9 months after diagnosis with leptomeningeal metastasis. To the best of our knowledge, the present case report is the first to describe leptomeningeal metastasis from pulmonary LCNEC confirmed by neuroimaging and cerebral spinal fluid cytology. It suggests that leptomeningeal metastasis does occur in this rare disease, and aggressive treatment may result in improved symptoms and possibly survival times.
IntroductionPulmonary large-cell neuroendocrine carcinoma (LCNEC) is a rare type of lung cancer that accounts for <1% of all primary lung malignancies (1). Since the biological behavior of LCNEC is similar to that of small cell lung cancer (SCLC), patients with LCNEC are often misdiagnosed and have an extremely poor prognosis (2). The 5-year survival rates for patients with LCNEC have been revealed to be significantly decreased compared with patients with other histological types of non-small cell lung cancer (NSCLC) (2,3).The common sites of metastasis from LCNEC are the liver, adrenal glands, bone, and brain, with hematogenous metastasis being the primary cause of treatment failure. Until recently, the rare sites of metastases from LCNEC which have been reported include the ovaries, small intestine, mandible, tonsil, vulva and prostate (4-9). In addition, Tsimpas et al (10) reported a case of LCNEC metastasis in the cauda equina; however, the patient in this study did not receive a cerebrospinal fluid (CSF) test and was not able to be diagnosed with leptomeningeal metastasis. Paydas et al (11) reported a case of leptomeningeal metastasis from LCNEC, but no cytological examination had been performed and no line-enhancement imaging for the diagnosis of leptomeningeal metastasis was performed for the patient. To the best of our knowledge, the present case report is the first to describe leptomeningeal metastasis from pulmonary LCNEC confirmed by neuroimaging and CSF cytology. Thu...