Histologic features of organizing pneumonia pattern

Key histologic features

Organizing pneumonia: intraluminal organizing fibrosis in distal airspaces (bronchioles, alveolar ducts, and alveoli)

Patchy and peribronchiolar distribution

Preservation of lung architecture

Uniform and recent temporal appearance

Mild interstitial chronic inflammation (eg, lymphocytes and edema)

Foamy macrophages are common in alveolar spaces, likely due to bronchiolar obstruction

Pertinent negative findings

Absence of severe fibrotic changes (eg, honeycombing); incidental scars or apical fibrosis may be present

Granulomas are absent; giant cells are rare or absent

Lack of prominent infiltration of eosinophils or neutrophils

Absence of necrosis or abscess

Absence of vasculitis

Lack of hyaline membranes or prominent airspace fibrin*

* Intra-alveolar fibrin deposition is seen in acute fibrinous and organizing pneumonia; it is unclear whether this is a separate entity or a variant of organizing pneumonia.

Graphic 60654 Version 5.0

خرید پکیج

Histologic features of organizing pneumonia pattern