Chronic restrictive lung disease

• various diverse etiologies that share a common clinical picture

Chronic diffuse interstitial lung disease

• patient becomes short of breath and you find that his lung is stiff

• in over 2/3 of cases, etiology is unknown

  • often occurs post ARDS

  • drug- and treatment-related

  • immunologic disorders

Lung cells

• type I pneumocytes cover 95% of alveolar surfaces and are vulnerable to injury; less numerous than type II pneumocytes

• type II pneumocytes are more numerous and produces surfactant. eventually, they differentiate into type-I-like cells

Interstitial space contains

• fibrin, collagen, elastin, ECM

• monocytes, macrophages, lymphocytes

Stimulation of macrophage leads to recruitment of neutrophils and subsequent activation of fibroblasts

• so one type of cell (type I cell) respond to this injury

• type II then replaces dying type I cells

• histology semi-acute, then chronic with lots of fibrosis
  

• gross diagram : progression of fibrosis, contraction of thickened wall stretches air spaces wider

• development of honeycomb

• stiff lung

• gross: honeycomb lung
  

Category: Pathology Notes