Iowa State University Veterinarian Records, RS 22/6/0/9, University Archives, Special Collections Department, Iowa State University, http://www.add.lib.iastate.edu/spcl/arch/rgrp/22-6-0-9.html
Pharyngeal lymphoid hyperplasia (PLH) is a condition in horses involving proliferation of one of the equine tonsillar structures. It has been diagnosed more frequently in the past few years due to a greater awareness of its existence, a developing prevalence of endoscopic examination, and/or an increased incidence of the syndrome.
Neumeister, Mary Lynn and Reinertson, E. L.
"Pharyngeal Lymphoid Hyperplasia,"
Iowa State University Veterinarian: Vol. 44
, Article 1.
Available at: http://lib.dr.iastate.edu/iowastate_veterinarian/vol44/iss1/1