Bone Marrow Biopsy and Its Utility in the Diagnosis of AL Amyloidosis and Other Plasma Cell Dyscrasias

Abstract

Amyloid disease should be suspected when organ dysfunction occurs at multiple sites; the diagnosis of amyloidosis is made by histological evaluation of a tissue biopsy using a Congo red stain. Approximately 75% of patients with systemic amyloidosis have the AL type associated with amyloidogenic immunoglobulin light chains originating from plasma cells present in the bone marrow. Thus, following confirmation of the presence of amyloid, the next step is to perform a bone marrow biopsy, assess plasma cell volume and clonality, and review for concomitant conditions, such as multiple myeloma or B-cell proliferative disorders (Rajkumar et al., Cancer 82:1501–1505, 1998; Sanchorawala et al., Am J Hematol 81:692–695, 2006). In this chapter, we will describe bone marrow biopsy staining procedures, review characteristic bone marrow biopsy findings in patients with AL amyloidosis (including the immunophenotypic profile of plasma cells), highlight the role of the Congo red stain in diagnosing amyloid, compare and contrast methods for establishing a diagnosis of a plasma cell dyscrasia, correlate bone marrow results with laboratory detection of paraproteins, and delve into molecular and cytogenetic features of patients with AL amyloidosis.