Cancer of unknown primary
From IDWiki
Differential Diagnosis
By overall frequency
- Lung (27%)
- Pancreas (24%)
- Liver or biliary (8%)
- Renal or adrenal (8%)
- Colorectal (7%)
- Genitourinary (7%)
- Stomach (6%)
- Unknown even with autopsy (27%)
By biopsy result
| Tumor type | % | Potential occult primary (site/types) |
|---|---|---|
| Well or moderately differentiated adenocarcinomas | 60 | Lung, pancreas, hepatobiliary tree, kidney, colon, ovary, breast |
| Squamous-cell carcinomas | 5 | Head and neck, lung, cervix, penis, vulva, bladder |
| Carcinomas with neuroendocrine differentiation | 1 | Pancreas, GI tract, lung |
| Poorly differentiated carcinomas (including poorly differentiated adenocarcinomas) | 25–30 | Adenocarcinoma, melanoma, sarcoma, lymphoma |
| Undifferentiated neoplasm | 5 | Carcinoma, lymphoma, germ-cell tumors, melanoma, sarcoma, embryonal carcinoma |
Investigations
| Assessment suggested | Target patient population |
|---|---|
| H&P | All patients |
| Basic bloodwork | All patients |
| CT chest/abdo/pelvis | All patients |
| Mammography | Women |
| Work-up for CUP subsets | |
| Breast MRI | Women with axillary adenocarcinoma |
| Serum AFP and hCG | Patients with midline metastatic disease |
| Serum PSA | Men with adenocarcinomatous bone metastases |
| Head and neck CT/PET scan (optional) | Cervical squamous cell carcinoma |
| Endoscopies | Sign/symptom/laboratory-oriented |
| Octreoscan and plasma chromogranin A | Patients with neuroendocrine tumour CUP |
| Additional diagnostic pathology | Sign/symptom/laboratory-oriented |
Further Reading
- Cancers of unknown primary site: ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up . Ann Oncol. 2015;26 Suppl 5:v133-8.
- SEOM clinical guideline on unknown primary cancer (2017). Clin Transl Oncol. 2018; 20(1): 89–96.
