Cutaneous plasmacytosis: Report of 6 cases with or without systemic involvement

• Published in: Journal of the American Academy of Dermatology Vol. 68; no. 6; pp. 978 - 985
• Main Authors: Honda, Rie, MD, Cerroni, Lorenzo, MD, Tanikawa, Akiko, MD, Ebihara, Tamotsu, MD, Amagai, Masayuki, MD, Ishiko, Akira, MD
• Format: Journal Article
• Language: English
• Published: United States Mosby, Inc 01.06.2013
• Subjects: Adult; cutaneous plasmacytosis; Dermatology; Female; Humans; Hypergammaglobulinemia - diagnosis; Immunohistochemistry; Male; marginal zone lymphoma; Middle Aged; mixed connective-tissue disease; multicentric Castleman disease; Plasma Cells - pathology; Retrospective Studies; sarcoid reaction; Skin - pathology; Skin Diseases - diagnosis; systemic plasmacytosis; IL; human herpesvirus; cutaneous plasmacytosis; sarcoid reaction; mixed connective-tissue disease; marginal zone lymphoma; MCD; HHV; multicentric Castleman disease; systemic plasmacytosis; interleukin; PCR; polymerase chain reaction
• DOI: 10.1016/j.jaad.2012.11.031
• ISSN: 0190-9622

Background Cutaneous plasmacytosis and systemic plasmacytosis are rare entities arising primarily in patients of Japanese descent. The origin and exact pathogenesis are poorly understood. Objective We sought to determine clinicopathologic features of cutaneous and systemic plasmacytosis. Methods We describe the clinicopathologic features of 6 patients with cutaneous plasmacytosis with or without systemic involvement (male:female = 3:1; mean age: 49.7 years; median age: 50.5 years; age range: 29-64 years). Results Patients presented clinically with multiple, red-brown infiltrated plaques and flat tumors, mainly located on the trunk. Histology revealed in all cases the presence of clusters of mature plasma cells within the dermis. Lymphoid follicles with reactive germinal centers were seen in 3 cases. Five cases showed the expected polyclonal expression of immunoglobulin light chain by the plasma cells, but monoclonality was observed in 1 case, thus showing overlapping features with cutaneous marginal zone lymphoma. One patient revealed overlapping features with multicentric Castleman disease. Limitations This was a retrospective study on a relatively small number of patients. Conclusions Despite typical clinical presentation, some of our patients presented with histopathologic and immunohistochemical features that deviated from the conventional appearance. Our observation confirms and expands previous observations of this elusive entity, suggesting that the spectrum of clinicopathologic presentations may be wider than previously recognized.