Solitary Necrobiotic Xanthogranuloma of an Upper Extremity in Association With Multiple Myeloma

May 2014 | Volume 13 | Issue 5 | Case Reports | 598 | Copyright © May 2014


E. Eugene Bain III MD,a Shane A. Meehan MD,a Elizabeth K. Hale MDa,b

aNew York University Ronald O. Perelman Department of Dermatology, New York, NY
bCompleteSkinMD, New York, NY

Abstract
Necrobiotic xanthogranuloma (NXG) is an uncommon granulomatous disorder of unknown pathogenesis that often presents with yellowish plaques in a periorbital distribution. While a majority of cases are associated with an underlying paraproteinemia of the IgG kappa type, a much smaller number are found to be associated with an underlying multiple myeloma. We present a case of a 78-year-old male with an isolated lesion of NXG on his right upper extremity. Following his diagnosis of NXG, further investigation for underlying systemic disorders with serum immunofixation revealed a monoclonal IgG kappa immunoglobulin with an M-spike of 1.2 g/dL. A PET-CT demonstrated bone destruction in the left proximal fifth rib, left scapula, the anterior lumbar I (L1) vertebrae, the left lumbar III (L3) vertebrae posterior elements and possibly left sacrum. A bone marrow biopsy revealed 18 % plasma cells. With these findings he was diagnosed with stage I multiple myeloma. Though clinically unimpressive and atypical in location for NXG, early biopsy and diagnosis of this solitary lesion led to the discovery of his hematopoietic disorder.

J Drugs Dermatol. 2014;13(5):598-600.

BACKGROUND

Necrobiotic xanthogranuloma (NXG) is a rare, granulomatous disorder of unknown etiology that often presents as firm plaques and nodules with a yellow-brown to red coloration. First described by Kossard and Winkelmann in 1980, lesions may have associated telangiectases and ultimately ulcerate. Healing typically occurs with scarring.1 NXG is associated with an underlying paraproteinemia in a majority of cases-usually of the IgG kappa type.2
Skin lesions often present in a periocular distribution, but have also been reported to occur on other areas of the head and neck as well as the trunk and extremities.3-4 NXG has also been found within skeletal muscle as well as various internal organs including the heart, lungs, brain, oral mucosa, larynx, and reticuloendothelial system.5-10
In addition to its hematologic associations, other systemic manifestations may be observed in patients with NXG. Along with paraproteinemias and multiple myeloma, NXG has also been reported to occur in association with other malignancies including leukemias, lymphomas and mycosis fungoides.4,9
On biopsy, lesions of NXG are characterized by a granulomatous infiltrate that usually involves the entire dermis and often extends into the subcutis. Broad areas of degenerated collagen (necrobiosis) are surrounded by histiocytes arranged as palisades. Cholesterol clefts, nodular collections of lymphocytes with or without plasma cells are also commonly found.3
We report a case of an isolated cutaneous lesion of NXG appearing on the right upper extremity in a 78-year-old male who presented with no other clinical signs or symptoms. Following biopsy of this lesion, the subsequent systemic evaluation led to the discovery of a previously undiagnosed multiple myeloma.

CASE REPORT

Our patient is a 78-year-old male who initially presented with a violaceous, indurated papule on his right upper arm that was completely asymptomatic (Figure 1). Biopsy of this lesion revealed a palisading granulomatous dermatitis with extensive areas of degenerated collagen (Figures 2-3). Special stains for fungal organisms, acid-fast bacilli and polarized material were negative. These findings were felt to be most consistent with an atypical necrobiotic xanthogranuloma.
His past medical history was remarkable only for hyperlipidemia that had been controlled with atorvastatin. He had no known history of diabetes mellitus or impaired glucose tolerance.He was taking no other medications or supplements, prescription or over-the-counter.
Given that the initial biopsy raised concern for a possible paraneoplastic phenomenon, additional laboratory studies were obtained including serum immunofixation that revealed a monoclonal IgG kappa immunoglobulin with an M-spike of 1.2 g/dL. The total serum IgG was elevated at 1,780 mg/dL (normal 639-1349 mg/dL). Serum IgM was slightly decreased at 51