ConditionsCancer (Malignant Neoplastic Diseases)Cancer With Primary Site Unknown
Blue Book Listing 13.22

Cancer With Primary Site Unknown

Metastatic cancer where the origin can't be identified.

What you have to prove

Metastatic carcinoma, except for squamous cell carcinoma confined to the neck nodes.

Medical evidence SSA expects

Pathology (from biopsied metastasis), imaging survey, and oncology notes.

Common misconceptions

Squamous cell head/neck lymph node disease from an unknown primary is sometimes curable and therefore excluded. Most true unknown-primary adenocarcinomas meet the listing.

Didn't meet the listing? You can still qualify via a Medical-Vocational Allowance — SSA's determination that your residual functional capacity, combined with your age, education, and work history, leaves no jobs you can do. See our appeals guide for what to do after an initial denial.