A 68-year-old man presents with a history of recurrent bilateral pleural effusions over the past six months and recent CT scan of the chest showing persistent small bilateral effusions ground-glass opacities in the superior segment of the left lower lobe and surrounding atelectasis. The patient underwent thoracoscopy and local pleurectomy and wedge biopsy of the left lower lobe. Additional history obtained post hoc disclosed a 5-year history of Waldenstrom's macroglobulinemia.
Pulmonary AmyloidosisPulmonary amyloidosis includes a spectrum of clinicopathologic entities that commonly have deposition of amorphous, eosinophilic, fibrillar amyloid proteins in extracellular spaces in the alveolar interstitum, around blood vessels, and/or in the tracheobronchial submucosa.Four clinical syndromes are associated with pulmonary amyloidosis:
- Systemic or Generalized
- Limited or Localized
- Diffuse Alveolar Septal
There are three main types of limited amyloidosis that involve the lung:
- diffuse alveolar septal
Multinucleated foreign-body-type giant cells are frequently seen around the edges of nodular deposits but are an uncommon finding in the diffuse alveolar septal pattern. This case showed an area with numerous giant cells and intracellular "ingested" amyloid could be demonstrated with a Congo red stain. Stains for AFB and fungi were performed to rule out infection and were negative.
The usual pulmonary pathology textbooks can be referenced. Hope you enjoyed!