Detection of Cauda Equine Syndrome With 18F-FDG PET/CT and Leptomeningeal Metastasis by 68Ga-DOTATATE in the Same Patient With Large Cell Neuroendocrine Carcinoma of Lung.

Leptomeningeal metastasis is the metastatic spread of the disease to leptomeninges from solid tumors such as breast, lung cancer, and melanoma. Cauda equine syndrome is a neurological condition caused by compression of the cauda equine. The incidence of large cell neuroendocrine carcinoma in resected lung cancers appears to be 2.1% and 3.5%. The incidence of clinically diagnosed leptomeningeal metastasis in patients with solid tumors is approximately 5%. Here, we present cauda equine syndrome caused by the metastasis of large cell neuroendocrine carcinoma detected by 18F-FDG PET/CT and also 68Ga-DOTATATE PET/CT.