Prof. Andrew M. Schreiner, Dept. of Pathology and Laboratory Medicine, New York Presbyterian Hospital, Weill Cornell Medical Center, New York, USA

The patient is an 83 year-old female who presented with cough.  Chest CT scan showed a right hilar mass.  CT-guided fine needle aspiration was performed.  The following are images from a ThinPrepTM slide:

 fig 1 march10 Fig. 1
 fig 2 march10  fig 3 march10
Fig. 2 Fig. 3

Your diagnosis?