Utility of cytokeratin 7 and 20 for the diagnosis cerebral metastases of adenocarcinoma

Objective: Histological features of metastasis are not always specific of t he origin. The usefulness of cytokeratin 7 and 20 (CK7 and CK20) in cerebra l metastases from an adenocarcinoma was studied in a series of 78 patients. Results. metastases from lung adenocarcinoma showed a CK7+/CK20- pattern in 79% of cases, CK7+/CK20+ in 19% and CK7-/CK20- in 2%. When observed positi vity for cytokeratin 20 was generally focal or weak. Breast adenocarcinoma metastases were CK7+/CK20- in 71% of cases CK7-/CK20- in 29%. less differen tiated rumours were usually negative for both cytokeratins. Metastases by c olonic adenocarcinoma were CK7-/CK20+ in 100% of cases. Cytokeratins 7 and 20 are useful Co distinguish lung from colonic metastatic carcinoma. in cas e of double positivity, a more intense CK7 expression is rather suggestive of a lung origin. Conclusion: these results might modify paraclinic investigations m search o f the primitive tumor.