Pluteus pouzarianus is a similar species that differs from Pluteus cervinus by its lack of raphanoid smell, presence of clamps in the pileipellis, a two layered pileipellis of hyaline hyphae overlaying brown hyaphae, and growth on coniferous wood.

Another name that gets thrown around is P. magnus. Mike Wood found the following two descriptions in the literature for Pluteus magnus:

Singer, R. (1956). Contributions Towards a Monograph of the Genus Pluteus. Transactions of the British Mycological Society 39, 145-232.
&
Banerjee, P. & Sundberg, W.J. (1995). The Genus Pluteus Section Pluteus (Pluteaceae, Agaricales) in the Midwestern United States. Mycotaxon 53, 189-246.

He has photocopies of these descriptions at:
http://www.mykoweb.com/...
http://www.mykoweb.com/...

A description of P. pouzarianus by Else Vellinga can be found in.

Bas, C., Kyper, Th. W., Noordeloos, M. E. & Vellinga, E. C. (1990). Flora Agaricina Neerlandica—Critical monographs on the families of agarics and boleti occuring in the Netherlands. Volume 2. Pluteaceae, Tricholomataceae. A. A. Balkema: Rotterdam, Netherlands. 137p.

and online at:

Google Books

MykoWeb has photos and comments on P. pouzarianus at:

http://www.mykoweb.com/CAF/species/Pluteus_pouzarianus.html

With this group a little microscopy goes a long way.