This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Pathology
Conglomerate Nodules in X-ray seen in? 
Select and explain. 
A. Hypersensitivity Pneumonitis, B. Sarcoidosis, C. Silicosis, D. Lobar Pneumonia
C: Silicosis
Answer: C: Silicosis 
Explanation: Complicated Silicosis (Progressive Massive Fibrosis--PMF)Massive fibrosis and conglomerate nodule formation in upper lobes with scarring and retraction of hilar upwardsConglomerate nodules are > 1 cm in size usually in mid-zone or periphery of upper lobes Compensatory emphysema occurs in lower lung fields Nodules tend to disappear from rest of lung when PMF develops Progressive Massive Fibrosis (PMF) may cavitate from tuberculosis or ischemic necrosis(Refer: Wolfgang F.Dahne's Radiology Review Manual, 6th edition, pg no: 532)