High
Power #10643,These entities are benign, reactive, proliferative lesions of the
conjunctiva characterized clinically by a yellow-white thickening with
increased vascularity.Sunlight and other environmental exposure are thought to be
predisposing elements.These lesions are both identical histopathologically with the
pinguecula being limited to the area of the conjunctiva (#21874) and the
pterygium encroaching on the cornea (#11996, #21876, #21972).Histologically, these lesions are characterized by degeneration of
collagen in the substantia propria of bulbar conjunctiva (elastoid and
basophilic degeneration)(#21879).The epithelium is alternately thinned (atrophy) or thickened (proliferative)
and shows no atypia(#21877, #10643).This is not pre-malignant as is the counterpart of this lesion in
the skin (solar or actinic keratosis).
