doi:10.1007/s12094-017-1807-yengLosa, F.Soler, G.Casado, A.Estival, A.Fernández, I.Giménez, S.Longo, F.Pazo-Cid, R.Salgado, J.Seguí, M.Á.SEOM clinical guideline on unknown primary cancer (2017)ART-2017-104275Cancer of unknown primary site is a histologically confirmed cancer that manifests in advanced stage, with no identifiable primary site following standard diagnostic procedures. Patients are initially categorized based on the findings of the initial biopsy: adenocarcinoma, squamous-cell carcinoma, neuroendocrine carcinoma, and poorly differentiated carcinoma. Appropriate patient management requires understanding several clinical and pathological features that aid in identifying several subsets of patients with more responsive tumors.2017http://zaguan.unizar.es/record/6528910.1007/s12094-017-1807-yhttp://zaguan.unizar.es/record/65289oai:zaguan.unizar.es:65289Clinical and Translational Oncology 20 (2017), 89 – 96byhttp://creativecommons.org/licenses/by/3.0/es/info:eu-repo/semantics/openAccess