13.  35 year old man with fatigue and pallor.  After an abnormal peripheral blood smear was obtained (panel 1), chest radiographs were taken that showed an anterior mediastinal mass.   It was excised.

Diagnosis = Intrathymic yolk sac carcinoma, with intratumoral myeloblastic differentiation & secondary acute myeloid leukemia

(Mouse-swipe links below, right-click, & choose "Open Link")

http://ijs.sagepub.com/content/10/2/157.refs

http://onlinelibrary.wiley.com/doi/10.1002/1097-0142%2819940301%2973:5%3C1535::AID-CNCR2820730537%3E3.0.CO;2-7/full