Summary

Cardiac amyloidosis is a form of restrictive cardiomyopathy resulting from the accumulation of misfolded protein aggregates in the myocardial extracellular space. Cardiac amyloidosis stems primarily from the misfolding of monoclonal immunoglobulin light chains (AL) originating from abnormal clonal plasma cell proliferation or transthyretin amyloidosis (ATTR).

Diagnosis of amyloidosis demands a high index of suspicion and requires histological confirmation of pathognomonic green birefringence under polarized light when an infiltrated tissue specimen is stained with Congo-red staining [1,2].

Pleural involvement of systemic amyloidosis has rarely been reported and is considered a serious complication [3]. Pleural amyloidosis is diagnosed with the identification of amyloid deposits in pleural biopsy specimens. However, pleural biopsies are rarely performed for this indication.

We describe the case of a patient with AL cardiac amyloidosis presenting as intractable pleural effusion and diagnosed via pleural biopsy.