This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory System, Subject name: Radiology
Chest X-ray showing opacity in the lung with irregular calcification is suggestive of 
Select and explain. 
A. Lung carcinoma, B. Hamartoma, C. Hydatid cyst, D. Adenoma
B: Hamartoma
Answer: B: Hamartoma 
Explanation: Ans. b (Hamartoma) (Ref. Harrison's medicine 17lh/558)Opacity in the lung with irregular calcification, i.e., poporn calcification = Hamartoma.The calcification of hamartomas can be stippled or conglomerate, referred to as "popcorn" calcification.# Opacity in the lung with "Bull's eye" calcification Lung granuloma# Opacity in lung with "Air crescent" SignAspergilloma (fungal ball).# Asympyomatic opacity in the lung without calcification can be Adenoma & bronchial atresia.# Opacity in the lung with corona radiate and or amorphous calcification Lung carcinoma# Opacity in lung with 'cyst in cyst'/floating water lilly/Callomate signHydatid cyst.# Opacity in the lung without calcification (if at all present-is arc-like) Hydatid cyst Also know:Carney's triad: multiple pulmonary chondromas + gastric epithelioid + extra-adrenal pheochromocytomas paragan- glioma.