Introduction: Non-Langerhans cell histiocytoses (non-LCH) are a group of rare diseases with varied clinical manifestations and overlapping features seen among the subtypes. Here, we present a case of Rosai-Dorfman disease with features of necrobiotic xanthogranuloma. Case: A 45-year-old female presented with a 10-year history of an enlarging neck mass with normal overlying skin accompanied by dysphagia and multiple asymptomatic pink to yellowish-brown papules, nodules, and plaques on the face, trunk and extremities. Biopsies of a skin nodule and plaque revealed granulomatous dermal infiltrates (lymphocytes, foamy histiocytes, and Touton giant cells), emperipolesis and areas of necrosis. CD1A and Fite-Faraco staining showed negative results while CD68 and S100 positively stained the tissues of interest. Histopathology of the neck mass paralleled these findings in addition to being negative for lymphoid markers. Patient had monoclonal gammopathy and thyromegaly with enlarged cervical lymph nodes on further tests and imaging. Intralesional and systemic steroids were given which led to flattening of skin lesions and improvement in dysphagia, respectively. Conclusion Diagnosis and classification of a particular type of non-LCH may be difficult due to similarities across its subtypes. Hence, it is our belief that these diseases may occur on a spectrum. Treatment involves a multidisciplinary approach for the best possible care.
Histiocytosis ; Histiocytosis, Sinus ; Necrobiotic Xanthogranuloma