[1321] Plasma Cell (Zoon's) Balanitis Is Another Inflammatory Disorder That Can Be Rich in IgG4+ Plasma Cells

Nidhi Aggarwal, Anil V Parwani, Jonhan Ho, Steven H Swerdlow. University of Pittsburgh, Pittsburgh, PA

Background: The presence of numerous IgG4+ plasma cells (PC) that make up a high proportion of all IgG+ PC is an important criterion in the diagnosis of IgG4-related sclerosing disease, a steroid-responsive fibro-inflammatory disorder. However, there is a growing list of other specific inflammatory disorders that may mimic IgG4 sclerosing disease, such as rheumatoid synovitis, and oral inflammatory diseases. Plasma cell (Zoon's) balanitis (PCB) is a chronic inflammatory dermatosis involving the glans and foreskin with a plasma cell rich infiltrate. Whether any cases might have numerous IgG4+ plasma cells and therefore raise the possibility of IgG4 disease (which is not sclerotic at some sites) is unknown.
Design: We therefore reviewed the histologic features of 14 plasma cell rich infiltrates in penile/ foreskin lesions that would fulfill the criteria for PCB and stained them with antibodies to CD3, CD20, CD138, Kappa, Lambda, IgG, and IgG4. IgG4 cells were counted in the areas where they were the most dense. Clinical history was reviewed to look for any evidence of IgG4 related disease elsewhere.
Results: The 14 patients were adults (35-91 years) who presented with penile lesions that showed ulceration in 11. One patient had a past history of liver transplantation and none had any history suggestive of IgG4 related disease at other sites. All biopsies showed an infiltrate rich in PC (See figure: left image) with variable numbers of B and T cells that occasionally formed aggregates. 6/14 (43%) cases had more than 50 IgG4+ PC/ high power field (See figure: right image), 2 of which (overall 14%) had a IgG4/IgG ratio ≥ 40%.

One very PC-rich case had >200 IgG4+PC/HPF and an IgG4/IgG ratio of almost 100%. 12/14 cases were clearly polytypic; however, 2 cases demonstrated an increased proportion of Κ+ PC (Κ:Λ∼ 5-6:1, 1 diffusely with polyclonal molecular studies and 1 focally).
Conclusions: Plasma cell (Zoon's) balanitis should be added to the list of chronic inflammatory conditions that may have numerous IgG4+ plasma cells and a high IgG/IgG4 ratio, without clear evidence of IgG4-sclerosing disease. It also may demonstrate skewed Κ:Λ ratios without being indicative of a malignant lymphoma.
Category: Hematopathology

Monday, March 4, 2013 9:30 AM

Poster Session I Stowell-Orbison/Surgical Pathology/Autopsy Awards Poster Session # 198, Monday Morning


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