Teratoma With Mediastinal Embryonic Carcinoma Concomiting Hystiocytic Sarcoma In The Bone Marrow

Background: Association of extragonadal germ cell tumors EGCT with haematological malignancies is rare with a very limited prognosis. Methods and findings: We report a case of a man, 21 years old, with progressive dyspnea, chest pain, night sweats, generalized edema, hemoptysis, pancytopenia and increased serum levels of alpha-fetoprotein (AFP), beta-fraction of the hormone chorionic gonodotrophin (beta-HCG) and lactic dehydrogenase. Chest computed tomography described a mediastinum mass measuring 11.3 x 7.3 cm whose biopsy revealed malignant germ cell neoplasia expressing positivity for cytokeratin, CD30 and AFP, indicating an embryonal carcinoma with teratoma. Bone marrow biopsy revealed interstitial infiltration by malignant neoplastic cells positive for CD68, CD163 and lysozyme, allowing the diagnosis of histiocytic sarcoma. The patient had a poor evolution, with death, sixteen days after admission. Conclusion: Histiocytic proliferations are very rare and rapidly fatal. Etiopathogenic theories for the simultaneity of these malignancies have been described based on processes of transformation from a same cellular precursor.