Fine needle aspiration biopsy features with histologic correlation inmediastinal hepatoid yolk sac tumor presenting with sternum metastasis:a case report.
BACKGROUND: The hepatoid variant of yolk sac tumor (H-YST) is an exceedinglyrare and highly malignant neoplasm. We present and discuss our experience with cytologic andhistopathologic features of a mediastinal H-YST presenting with sternum metastasis, which to thebest of our knowledge has not been previously reported. CASE: A 38-year-old man presented with alarge mass on the sternum. Computed tomography of the thorax showed a large anterior mediastinalmass with sternum metastsis and multiple lung metastases. Laboratory examination revealed elevatedserum alpha-fetoprotein (60,000 IU/mL). No tumor was found in the other organ systems. Apercutaneous fine needle aspiration biopsy and subsequent open surgical biopsy were performed on thesternum metastasis. Cytologically, the tumor was composed of monotonous, large, round to polygonalhepatoid cells forming solid sheets and trabeculae entrapped with endothelial cells resemblinghepatocellular carcinoma. Histopathologic sections of tumor showed tumor cells with eosinophilic toclear cytoplasm arranged in a solid, trabecular growth pattern, with some acinar formations.Immunohistochemical study supported the hepatoid origin. CONCLUSION: Fine needle aspirationcytology, together with the characteristic clinical presentations and specific tumor markers, iscrucial to the initial diagnosis of H-YST.
Ceyhan,K　Utkan,G　Dincol,D　Erdogan,N　Erekul,S　Umudum,H
Division of Clinical Cytology, Department of Pathology, Faculty of Medicine,Ankara University, Turkey. korayceyhan@yahoo.com
Neoplasms　 Sternum　 biopsy characteristics　 Fine needle biopsy, NOS NeoplasmMetastasis
