Leptomeningeal metastasis of pulmonary large-cell neuroendocrine carcinoma: A case report and review of the literature.

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.