Question

A female presents with a history of progressive breathlessness. Histology shows heterogeneous patchy fibrosis with several fibroblastic foci. The most likely diagnosis is:

• A. Cryptogenic organizing pneumonia
• B. Non-specific interstitial pneumonia
• C. Usual interstitial pneumonia
• D. Desquamative interstitial pneumonia

Hint:

Patchy heterogeneous fibrosis plus fibroblastic foci equals UIP.

Answer 1

The Correct Option is C

The histology line is doing all the work here, so anchor on the two buzzwords. First, fibrosis that is heterogeneous and patchy means the scarring varies from place to place and from old to new, with damaged lung sitting right beside preserved lung. Second, fibroblastic foci are little nests of actively proliferating fibroblasts that mark ongoing injury. Put these together and you have the textbook signature of usual interstitial pneumonia, the tissue pattern underlying idiopathic pulmonary fibrosis, which classically presents with relentless progressive breathlessness. Now sweep the distractors. Non-specific interstitial pneumonia is the opposite in character: its fibrosis is uniform and time-synchronous across the lung and it pointedly lacks fibroblastic foci, so it cannot be the answer. Cryptogenic organizing pneumonia fills the distal airspaces with granulation-tissue plugs called Masson bodies rather than scarring the interstitium. Desquamative interstitial pneumonia, tied to smoking, packs the alveolar spaces with pigment-laden macrophages and again lacks the patchy heterogeneity. The only pattern that fits heterogeneous fibrosis plus fibroblastic foci is UIP. \[\boxed{\text{Usual interstitial pneumonia}}\]