Tailbone osteoma is generally divided into two kinds: one kind of primary tumor, the cause of which is not yet clear, may be caused by virus, chronic stimulation, genetic mutation, etc. The other is metastatic tumor, in which tumors in other parts of the body are transferred to the tailbone through the blood circulation and so on. 1. Primary tumor: the cause of its development is not clear yet, it may be caused by virus, chronic stimulation, heredity, gene mutation, etc. Primary tumors are divided into benign and malignant, benign tumors are common, such as hemangioma, aneurysmal bone cysts, giant cell tumor of bone, malignant isolated plasma cell tumors and multiple myeloma, chordoma, etc. 2. Metastatic tumor: many advanced cancers, such as breast cancer, lung cancer, etc., metastasize to the caudal vertebrae through blood circulation or lymphatic circulation. If diagnosed with caudal spine osteoma, it is recommended to have it treated and handled by professional doctors in specialized hospitals.