Extensive Pulmonary AL Amyloidosis Mimicking Miliary Tuberculosis: The Diagnostic Utility of 99m Tc-PYP Scintigraphy.

Amyloidosis is a misfolded protein deposition disorder within the extracellular matrix, leading to dysfunction in the affected organ. Primary amyloidosis manifests as AL and ATTR subtypes, wherein AL is associated with plasma cell dyscrasias. Herein we present a case of a patient who underwent investigation due to the presence of bilateral reticulonodular lung infiltrates, suggestive of miliary tuberculosis. 99m Tc-PYP scan revealed widespread radiotracer uptake in the lungs leading to diagnosis of AL amyloidosis.