Pulmonary amyloidosis: A case series

Abstract

Amyloidosis is a spectrum of diseases, in which various proteins which are usual components of plasma are deposited as insoluble beta-pleated sheets extracellularly, disrupting function of various organs. Amyloid light-chain amyloidosis occurs due to the deposition of proteins, derived from immunoglobulin light chains, routinely manifesting with multisystem involvement. Pulmonary involvement is seen in about 50% of cases. Three common patterns of pulmonary amyloidosis on computed tomography (CT) chest are tracheobronchial, nodular parenchymal, and diffuse alveolar septal variety. We hereby report two cases of pulmonary amyloidosis, one being a case of diffuse alveolar septal pulmonary amyloidosis, which is an extremely rare pattern of involvement, with a very poor prognosis, and the other one being tracheobronchial pattern of involvement, which usually results due to the localized deposition of amyloid in the tracheobronchial tree. Knowledge about pulmonary amyloidosis is important due to its poor prognosis and nonspecific findings in CT chest.

Keywords: Amyloid light-chain amyloidosis; apple-green birefringence; chemotherapy; diffuse alveolar septal pattern; diffuse parenchymal pattern; pulmonary amyloidosis; tracheobronchial amyloidosis; video-assisted thoracoscopic surgery-guided lung biopsy.

Figure 1

Computed tomography chest showing diffuse centrilobular nodules

Figure 2

Computed tomography chest repeated after 6 months showing worsening centrilobular nodules bilaterally

Figure 3

Lung biopsy showing Congo red-positive infiltrates

Figure 4

Computed tomography chest confirming right lower lobe collapse

Figure 5

Bronchoscopy showed partially occluded left lower lobe segmental bronchi and narrowed right lower lobe segmental bronchi with edematous mucosa