Cutaneous and subcutaneous metastases from internal malignancies: an analysis of cases diagnosed by fine needle aspiration.

Cutaneous and subcutaneous metastases from internal malignancies are rare and indicate a dismal outcome for the patient. This study is designed to analyze cases of cutaneous and subcutaneous metastases from a known or unknown primary and evaluate usefulness of fine needle aspiration cytology as a diagnostic modality. The present study is a retrospective analysis of 83 patients who were diagnosed with metastatic skin deposits on fine needle aspiration cytology. Seventy-four patients were previously diagnosed cases of malignancy and nine patients had metastatic deposits simultaneously with the primary tumor. The commonest malignancies showing cutaneous metastases were from breast, colon and rectum, lung, ovary, and thyroid. The differential diagnoses are from primary cutaneous tumors. FNAC provides a rapid diagnosis and should be used as a preferred first line diagnostic modality in such patients. In our study, FNAC yielded a sensitivity and specificity of 100% as a microscopic method for confirmation.