%0 Journal Article %T Cutaneous Plasmacytosis with Perineural Involvement %A Elizabeth A. Brezinski %A Maxwell A. Fung %A Nasim Fazel %J Case Reports in Dermatological Medicine %D 2014 %I Hindawi Publishing Corporation %R 10.1155/2014/840845 %X Importance. Cutaneous and systemic plasmacytosis are rare conditions of unknown etiology with characteristic red-brown skin lesions and a mature polyclonal plasma cell infiltrate within the dermis. Perineural plasma cell infiltrates may be a histologic clue to the diagnosis of cutaneous plasmacytosis. Observations. Our patient had a five-year history of persistent reddish-brown plaques on the neck and trunk without systemic symptoms. Histologic examination showed dermal perivascular and perineural plasma cells with excess lambda light chain expression. Due to decreased quality of life caused by his skin lesions, he was placed on a chemotherapeutic regimen with bortezomib. Conclusions and Relevance. The patient was diagnosed with cutaneous plasmacytosis based on classic histopathology results with a recently characterized pattern of perineural involvement. Bortezomib therapy was initiated to manage his skin eruption, which has not been previously described as a treatment for this chronic condition. 1. Introduction Cutaneous and systemic plasmacytosis are rare, lymphoplasmacytic disorders characterized by red-brown poorly circumscribed plaques and nodules occurring mainly on the trunk primarily in patients of Japanese descent [1, 2]. The disease can be accompanied by fever, lymphadenopathy, anemia, and a polyclonal hypergammaglobulinemia [2, 3]. The characteristic histopathology is dermal perivascular infiltrates of mature polyclonal plasma cells [2, 4]. Herein we present a Hispanic patient with chronic red-brown macules and plaques on the trunk where these distinctive biopsy findings supported the diagnosis of cutaneous plasmacytosis. We discuss the classical histopathologic features of cutaneous plasmacytosis and evidence for cutaneous-only involvement of this condition. 2. Case A 39-year-old Hispanic man presented with a five-year history of persistent red plaques on his neck and a two-year history of similar lesions that had spread to his trunk, sparing the upper and lower extremities. His past medical history included untreated latent tuberculosis infection and allergic rhinitis. Clinical examination revealed brownish-red macules and mildly indurated plaques on his trunk (Figure 1) and pink-to-violaceous plaques with fine scale on his neck. He was afebrile and had no lymphadenopathy. Laboratory examination showed normal complete blood count, serum protein, and erythrocyte sedimentation rate, no monoclonal protein on immunofixation, and hyperimmunoglobulin (Ig) E (199£¿KU/L¡ªnormal: <25£¿KU/L). The serum level of interleukin-(IL-) 6 was normal and %U http://www.hindawi.com/journals/cridm/2014/840845/