Occult metastatic mesothelioma--diagnosis by fine-needle aspiration. A case report.

Fine-needle aspiration biopsy of an enlarged right axillary lymph node was performed on a 33-year-old woman with Ebstein's cardiac anomaly. Microscopic examination of the cytologic material revealed large discohesive cells with abundant pale cytoplasm, "ruffled" cytoplasmic borders, and prominent central nucleoli. Immunocytochemical analysis of the aspirate confirmed the mesothelial origin of these cells and prompted the diagnosis of metastatic mesothelioma. Autopsy examination revealed a large pericardial mesothelioma with metastases to mediastinal and axillary lymph nodes. This case report demonstrates the usefulness of fine-needle aspiration biopsy in the diagnosis of metastatic mesothelioma.