All are true about silicosis except?: (A) Bifringent crystals seen, (B) Pleural plaque seen, (C) Lower lobe is ussualy involved, (D) Most common pnemoconiosis
Answer is C. Ans. (c) Lower lobe is ussualy involved(Ref: Robbins 9th/pg 689; 8th/pg 687)Silicosis involves upper lobe more commonly than lower lobe. Examination of the nodules by polarized microscopy reveals the birefringent silicate particles (silica is weakly birefringent).