Source:http://linkedlifedata.com/resource/umls/id/C0027667
MSH: Metastases in which the tissue of origin is unknown.,NCI: The spread of a malignant neoplasm from an unknown primary to another region remote from the primary site.,NCI: 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.