Keratotic vascular papules over the feet: a case of Waldenström’s macroglobulinaemia-associated cutaneous macroglobulinosis

Cutaneous Macroglobulinosis Presenting as Serpiginous Purpura, a Case Report and Literature Review

Cutaneous macroglobulinosis is a rare manifestation of Waldenstrom macroglobulinemia when there is deposition of IgM in the dermis. The clinical presentation varies from skin colored to pink papules and ulcerative nodules on trunk, extensor surfaces of upper and lower limbs to hyperkeratotic lesions on the soles. We herein report a 78-year-old-male with Waldenstrom macroglobulinemia who presented with serpiginous purpura. The differential diagnoses included occlusion of vessel lumen by the lymphoplasmacytoid cells, high level of IgM or cryoglobulin, as well as small to medium vasculitis secondary to Waldenstrom macroglobulinemia. The histopathology revealed vasculopathy and vasculitis, while further immunohistochemistry highlighted deposition in the vessel lumen and vessel wall with IgM, suggesting the diagnosis of cutaneous macroglobulinosis. In this case report, we discuss this rare presentation and reviewed previous cases of cutaneous macroglobulinosis.

Paraprotein deposits in the skin

Cutaneous manifestations secondary to paraprotein deposits in the skin include a group of different disorders that although rare, may be the first clinical manifestation of the underlying hematologic dyscrasia. In this article we review the clinical manifestations and histopathologic findings of the processes that result from specific deposition of the paraprotein in different structures of the skin. Paraneoplastic processes frequently associated with hematologic malignancies will not be covered in this review. Some of the disorders included here result from deposition of the intact paraprotein in the skin, whereas in other cases the lesions are due to deposition of modified paraproteins in the form of amyloid substance, cryoglobulins, or crystalglobulins. Cutaneous amyloidoma refers to nodular dermal deposits of amyloid derived from immunoglobulin light chains produced by local plasma cells in the absence of systemic amyloidosis. Dermatologists and dermatopathologists should be aware of the clinical and histopathologic features of these rare disorders because sometimes the cutaneous lesions are the first sign of an underlying silent hematologic malignancy with paraproteinemia.

Waldenström macroglobulinaemia presenting as tingling ulcers on the feet

A 56-year-old man presented with tingling ulcers on the feet. On further skin examination, papules on the knees were observed. Biopsies revealed extravascular eosinophilic deposits of IgM, and Waldenström macroglobulinaemia was diagnosed. The skin manifestations have resolved with chemotherapy. Peripheral neuropathy and storage papules are rare manifestations of Waldenström’s macroglobulinaemia.