The occult primary malignancy.
D001706:Biopsy; D002294:Carcinoma, Squamous Cell / Q000556:secondary* / Q000628:therapy; D006258:Head and Neck Neoplasms / Q000556:secondary* / Q000628:therapy; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology*; D008223:Lymphoma / Q000556:secondary / Q000628:therapy; D009333:Neck; D011379:Prognosis