Trigeminal neuralgia is a common disease, clinically divided into primary trigeminal neuralgia and secondary trigeminal neuralgia. Among the patients with secondary trigeminal neuralgia caused by various tumors, benign tumors account for the majority, and trigeminal neuralgia caused by malignant tumors is very rare in clinical practice. However, patients with trigeminal neuralgia secondary to malignant tumors are clinically atypical, difficult to diagnose and have poor prognosis, which should be highly valued by clinical workers. 1. Intracranial malignant tumors causing trigeminal neuralgia: benign tumors account for the majority of patients with secondary trigeminal neuralgia caused by various tumors, among which cholesteatoma of the pontocerebellar horn is the most common, followed by trigeminal nerve sheath tumor, meningioma, auditory neuroma and other tumors of the pontocerebellar horn, and trigeminal neuralgia caused by malignant tumors is very rare in clinical practice. Through the review of domestic and foreign literature for many years, we found that malignant metastases invading the skull base are the most common among malignant tumors causing trigeminal neuralgia, among which intracranial metastases to the nasopharynx, maxillary sinus, maxilla, parotid gland and soft tissue of the head and neck are the most common, followed by glioma and quadriple ventricular ventricular meningioma originating in the brain. In addition, intracranial metastases from esophageal cancer, lung cancer, gastric cancer, prostate cancer, malignant lymphoma, and basal cell carcinoma have also been reported in the individual literature. link M J et al. also reported a case of secondary trigeminal neuralgia in a patient with malignant transformation of cholesteatoma of the pontocerebellar horn into squamous cell carcinoma, which is very rare in the etiology of secondary trigeminal neuralgia. The predominant sites of intracranial metastases causing trigeminal neuralgia are the pontocerebellar horn region and the base of the middle cranial fossa, often invading the Meckel’s cavity. In contrast, malignant tumors of intracerebral origin are mainly located in the pontocerebellum and at the beginning of the trigeminal nerve. 2. Clinical characteristics of secondary trigeminal neuralgia caused by malignant tumors: In patients with secondary trigeminal neuralgia, the pain manifestations of patients with different nature of tumors also have their own characteristics. Patients with pontocerebellar horn cholesteatoma mostly show typical trigeminal neuralgia, or even the only symptom or the first symptom. Pontocerebellar horn tumors such as trigeminal nerve sheath tumor, meningioma and auditory neuroma can sometimes also show typical trigeminal neuralgia. However, the manifestation of trigeminal neuralgia caused by malignant tumor is often atypical clinically. Patients usually first show pain in the distribution area of a single branch of the trigeminal nerve, and then gradually expand to the distribution area of other branches as the tumor grows, and then develop into pain on one side of the face, and multiple groups of symptoms or subsequent symptoms may appear at the same time, such as facial sensory disorders, symptoms and signs of facial and auditory nerve involvement, and even somatic sensory and motor dysfunction. Intracranial metastases are very common but rarely cause trigeminal neuralgia, especially if the cancer stimulates or compresses the trigeminal nerve to cause trigeminal neuralgia symptoms before the primary lesion is detected and intracranial pressure is increased, it is easy to be mistaken for primary trigeminal neuralgia. Moreover, its pathogenesis is diverse, and patients are often seen in multiple departments for a long time, which brings many difficulties to clinical diagnosis. However, early detection and treatment of malignant tumors can have a great impact on the prognosis of patients, so it should be highly valued by clinical workers. For patients suspected of primary trigeminal neuralgia, comprehensive physical examination and detailed imaging should be performed, especially when the patient has atypical pain symptoms and there is adjacent cranial nerve dysfunction or malignant tumor in other parts of the body, the possibility of intracranial malignant tumor secondary to trigeminal neuralgia should be thought of.