Abstract
Background : Angiosarcoma is a rare and high-grade sarcoma that arises from the endothelial cells, occurring most commonly in the skin and soft tissues. Here, we describe the pleural fluid cytologic findings in a patient of cutaneous angiosarcoma with pleural metastasis.
Case : A 100-year-old woman with a history of cutaneous angiosarcoma of the left knee diagnosed two years previously was admitted to our hospital with fever and anorexia. Chest CT revealed massive pleural effusion on the left side. Cytologic examination of the pleural fluid revealed round to oval atypical cells with nuclei containing fine chromatin and prominent nucleoli ; the cells occurred both singly and in clusters. The distinguishing cytologic features included signet ring cell-like morphology, intracytoplasmic lumina-like features, acinar or gland-like formation, and a hobnail arrangement of the cells. The differential diagnosis based on these morphological features included adenocarcinoma and malignant mesothelioma. Immunohistochemistry of paraffin cell block sections of the pleural fluid revealed positive staining of the atypical cells for CD31, CD34 and D2-40, but negative staining for cytokeratin, suggestive of endothelial differentiation and confirming the diagnosis of metastatic angiosarcoma of the pleura.
Conclusion : In the present case, immunohistochemistry of the cell block sections was useful for a precise diagnosis of metastatic cutaneous angiosarcoma of the pleura.
