NCI Definition: The spread of a malignant neoplasm from an unknown primary to another region remote from the primary site. [1]

Disease Details

Metastatic Malignant Neoplasm of Unknown Primary, Metastatic Neoplasm of Unknown Primary Origin, Unknown primary malignant neoplasm (NOS), occult primary tumor, Unknown primary malignant neoplasm, Cancer of Unknown Primary Site, cancer of unknown primary origin, Metastatic Malignant Neoplasm of Unknown Primary Origin
Metastatic Malignant Neoplasm
Carcinosarcoma of Unknown Primary, Melanoma of Unknown Primary, Carcinoma of Unknown Primary, and Cancer of Unknown Primary, NOS
OncoTree Name
Cancer of Unknown Primary
OncoTree Code


1. National Cancer Institute. NCI Thesaurus Version 18.11d. https://ncit.nci.nih.gov/ncitbrowser/ [2018-08-28]. [2018-09-21].

2. The AACR Project GENIE Consortium. AACR Project GENIE: powering precision medicine through an international consortium. Cancer Discovery. 2017;7(8):818-831. Dataset Version 8. This dataset does not represent the totality of the genetic landscape; see paper for more information.

3. All assertions and clinical trial landscape data are curated from primary sources. You can read more about the curation process here.