The Collaborative International Dictionary of English v.0.48:

Karyostenosis \Kar`y*o*ste*no"sis\, n. [NL., fr. Gr. ka`ryon a
   nut, kernel + ? a being straitened.] (Biol.)
   Direct cell division (in which there is first a simple
   division of the nucleus, without any changes in its
   structure, followed by division of the protoplasm of the
   cell); -- in opposition to karyokinesis.
   [1913 Webster]