Definitions and usage
Heterogeneous: consisting of dissimilar elements.
Heterogenous: 1. not originating within the body; 2. of foreign origin; 3. heterogeneous.
Heterogeneous, with that fourth e, is the opposite of homogeneous (which is different from homogenous). Most of us will never have use for heterogenous in its most strictly defined senses, where it is a term used almost exclusively in biology and medicine. In general usage, however, it is commonly used in place of heterogeneous.
Post-transplant lymphoproliferative disease (PTLD) is a morphologically heterogenous group of lymphoid proliferations of varying clonal composition seen following bone marrow or solid organ transplantation. [Nature]
Signal characteristics in MRI and the heterogenous tumor blushin angiography suggested other possibilities. [European Journal of Cardio-Thoracic Surgery]
To succeed in a global marketplace, future managers need to fine-tune their ability to collaborate with and lead heterogeneous teams. [Fortune]
[T]hey’re minimalist, like his Imagism, a heterogeneous mixture of the colloquial and arcane, foreign languages and others’ voices, like the “Cantos.” [Wall Street Journal]
Members of this heterogeneous population may wed from each other, but they never or seldom agree on anything. [American Chronicle]