When tests are able to find the primary cancer, the cancer is no longer a CUP and treatment is based on the type of primary cancer.

Source: Childhood Carcinoma of Unknown Primary Treatment (PDQ®)–Patient Version, National Cancer Institute.

Source updated: January 12, 2024 · Captured 2026-09-09.

Selected source text with whitespace normalised. This Triangle page is not an NCI PDQ summary. Independent clinical review is pending.

When it is not known where the cancer first formed at diagnosis, adenocarcinomas, melanomas, and embryonal tumors (such as rhabdomyosarcoma or neuroblastoma) are tumor types that are often diagnosed later in children and adolescents.

Source links and citations

adenocarcinomas
melanomas
embryonal tumors
rhabdomyosarcoma
neuroblastoma
adolescents

Preserved source evidence · Independent clinical review pending · Not medical advice