JAAD ONLINE CASE Vulvar necrobiotic xanthogranuloma To the Editor: An 89-year-old Caucasian woman with a 1.5-year history of IgG monoclonal gammopathy of undetermined significance presented for evaluation of a large ulceration on the left buttock and an asymptomatic lesion on the vulva. On physical examination, she had an extensive well-defined indurated ulcer obliterating the clitoris and encompassing both labia majora (Fig 1, A) and an 8- 3 8-cm circular ulcer extending down to muscle on the left buttock with a necrotic rim (Fig 1, B). A 1.5-cm yellow nodule was present on the left lower eyelid, and a 4-cm oval yellow-pink plaque on the lateral distal aspect of her right thigh (Fig 1, C ). The patient was given the diagnosis of monoclonal gammopathy of undetermined significance 1.5 years before presentation with serum protein electrophoresis demonstrating 0.58 g/dL of monoclonal IgG paraprotein and elevated free

LETTERS kappa and lambda light chains. She refused bonemarrow biopsy. Laboratory studies were significant for stable anemia (hemoglobin of 10 g/dL), normal white blood cell count, normal complete metabolic panel findings, and normal liver function test results. Wedge biopsy specimen of the vulvar lesion and excisional biopsy specimen of the right leg plaque both showed large areas of necrosis surrounded by a prominent granulomatous reaction with histiocytes and multinucleated giant cells, consistent with necrobiotic xanthogranuloma (NXG) (Fig 2). The lesional cells stained positive for CD68 and CD163, in keeping with histiocytes. Pancytokeratin, S100 protein, and CD34 were negative. Special stains for organisms (Gomori methenamine silver and acid-fast bacillus) produced negative findings. NXG with paraproteinemia is a rare, chronic granulomatous disorder that presents as indurated yellow papules, plaques, and nodules in association

Fig 1. Necrobiotic xanthogranuloma. A, Large ulcer obliterating the clitoris and encompassing both labia majora with shiny, indurated borders. B, Large ulceration of the left buttock with necrosis surrounded by shiny, indurated borders. C, Yellow oval plaque on the distal aspect of right thigh. J AM ACAD DERMATOL

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Fig 2. A, Histopathology of vulvar and right thigh lesions. Skin biopsy specimens from both lesions show areas of necrosis surrounded by a prominent granulomatous reaction. B, Prominent histiocytes and multinucleated giant cells.

with a serum monoclonal gammopathy. Skin biopsy specimen demonstrates a dermal infiltrate composed of palisading granulomas with areas of necrosis and prominent giant cells. Most patients (80%) with NXG have a serum monoclonal gammopathy and a small percentage (10%) develop multiple myeloma.1 The vast majority of patients have periorbital lesions, particularly on the upper or lower eyelid, as in this case.2 Other sites of involvement include the face, trunk, and extremities.3,4 There are only 2 cases of NXG with mucosal or genital involvement reported in the literature. Fortson and Schroeter5 reported a case of NXG of the lips and tongue, and a review by Wood et al1 cited a 26-year-old man with penile NXG in a table summarizing the clinical findings in 12 patients with NXG. To our knowledge, this is the first case of NXG involving the female genitalia. Given the dramatic presentation and extent of genital involvement in this elderly female patient, the leading gynecologic diagnosis was squamous cell carcinoma. Biopsy specimen of the vulvar lesion was essential to rule out underlying malignancy and establish the diagnosis. The patient refused further workup and died 2 weeks after presentation from failure to thrive, although multiple myeloma cannot be ruled out as her underlying cause of death. This case demonstrates the potential for NXG to rapidly progress, leading to dramatic ulceration with significant morbidity and mortality and underscores the need for early recognition of this rare condition. Treatment options for NXG include surgery, intralesional and systemic corticosteroids, and other systemic therapies such as methotrexate, cyclophosphamide, and azathioprine. Vulvar NXG is now an entity that both dermatologists and gynecologists should be aware of, requiring prompt evaluation with biopsy and treatment to prevent potentially disfiguring and debilitating obliteration of the external female genitalia.

Ilana J. DeLuca, MD, PhD, and Marc E. Grossman, MD Department of Dermatology, Columbia University, New York, New York Funding sources: None. Conflicts of interest: None declared. Correspondence to: Ilana J. DeLuca, MD, PhD, Department of Dermatology, Columbia University, 161 Fort Washington Ave, 12th Floor, New York, NY 10032 E-mail: [email protected] REFERENCES 1. Wood AJ, Wagner VU, Abbott JJ, Gibson LE. Necrobiotic xanthogranuloma. Arch Dermatol 2009;145:279-84. 2. Spicknall KE, Mehregan DA. Necrobiotic xanthogranuloma. Int J Dermatol 2009;48:1-10. 3. Mehregan DA, Winkelmann RK. Necrobiotic xanthogranuloma. Arch Dermatol 1992;128:94-100. 4. Efebera Y, Blanchard E, Allam C, Han A, Lee A, Munshi N. Complete response to thalidomide and dexamethasone in a patient with necrobiotic xanthogranuloma associated with monoclonal gammopathy: a case report and review of the literature. Clin Lymphoma Myeloma Leuk 2011;11:298-302. 5. Fortson JS, Schroeter AL. Necrobiotic xanthogranuloma with IgA paraproteinemia and extracutaneous involvement. Am J Dermatopathol 1990;12:579-84. http://dx.doi.org/10.1016/j.jaad.2014.04.039

Pedicure-associated Mycobacterium chelonae infection in a hospitalized patient To the Editor: The Vanderbilt University Dermatology Consult Service was asked to evaluate a 60-year-old man with a history of nonischemic cardiomyopathy, congestive heart failure, and a 1-week history of painful swelling and ulcerations on his bilateral lower extremities. The patient had insulin-dependent