Multiple Myeloma Mimicking a Small Vessel Vasculitis Presentation

Abstract

Multiple myeloma can have different clinical manifestations, and not all patients present with classic CRAB component. We describe a 46-year-old woman admitted to our hospital with a complaint of a bluish-to-black discoloration of the second toe that was rapidly progressive and acute kidney injury. We documented a Kappa light chain monoclonal gammopathy, increased presence of plasmacytes in bone marrow aspiration, and multiple lytic bone lesions, which led to a diagnosis of multiple myeloma. Although multiple myeloma presenting with blue finger syndrome is uncommon, it must always be considered as a differential diagnosis with this clinical finding.

Figure 1

Black coloration (necrosis) of the second left-foot finger at admission.

Figure 2

Progression of necrotic lesions on the left foot: new lesions involving the right arm skin and retiform purpura.

Figure 3

Magnetic resonance images enhanced in short inversion time inversion recovery (STIR) in coronal (left and middle) and sagittal (right). The alteration in the signal of the bone marrow of the vertebral bodies and both iliac bones can be seen by countless discrete images with hyperintense signals of contours, rounded, diameters of up to 13 mm, which are compatible diffuse commitment by multiple myeloma. In addition, the asymmetry in the size of both kidneys can be observed. The adequate attention in a lesion suggestive of neoplasia.