syphilis tertiary syphilis MESH:C536774 DOID:8200 ICD10CM:A52 ICD9CM:097.0 disease_ontology UMLS_CUI:C0153188 NCI:C128414 SNOMEDCT_US_2020_03_01:72083004 A syphilis that is characterized as the third stage of syphilis that develops after the disappearance of the secondary symptoms and is marked by ulcers and gummas under the skin and commonly by involvement of the skeletal, cardiovascular, and nervous systems. late syphilis