Cutaneous Infiltration of Waldenstrom's Macroglobulinaemia-A Two-Case Series of a Diagnostically Challenging...

Cutaneous manifestations of Waldenstrom's macroglobulinaemia (WM), a rare B-cell lymphoproliferative disorder, present a diagnostic challenge. The intent of this article is to raise awareness to clinicians of a potentially overlooked condition, particularly in the context of patients with a monoclonal IgM paraproteinaemia, but also to describe the diagnostic complexity of the disease from a clinicopathological perspective.

We describe the clinical presentation and histopathological findings of two patients with cutaneous involvement of WM.

Cutaneous presentations included erythematous and salmon pink plaques, which were either tender or non-tender. Histopathology analysis in both cases demonstrated direct lymphocytic infiltration by malignant lymphocytes of WM, with case 1 demonstrating aberrant CD10 expression.

The broad cutaneous signs of WM are sparsely described in the literature, and these can even precede formal diagnosis. Ongoing clinical suspicion is warranted from both a clinical and histopathological perspective where patients present with a monoclonal IgM paraproteinemia.