MedicalTerminology DB
Cancer & Tumors Cancer & Oncology

occult primary tumor

Meaning of occult primary tumor: Cancer in which the site of the primary (original) tumor cannot be found.

Definition of occult primary tumor

Cancer in which the site of the primary (original) tumor cannot be found. Most metastases from occult primary tumors are found in the head and neck.

Written and maintained by James Murray Last updated July 21, 2026 Educational reference, not medical advice. Read the limitations.

For learning, not diagnosis. This glossary provides general educational information and is not a substitute for advice from a qualified healthcare professional. If you may be experiencing a medical emergency, contact local emergency services.