Primary Cutaneous Plasmacytosis: Masquerading as Hidradenitis Suppurativa

Isolated cutaneous plasmacytosis (CP) is a rare entity with few cases reported in world literature. CP masquerading as hidradenitis suppurativa like presentation is a unique case with some features differentiating it clinically from it which were further confirmed by histopathology and immunostaining. Our case showed hyperplasia of mature plasma cells and polyclonal hypergammaglobulinemia, immunostaining for CD138 positivity and kappa: lambda ratio more than 3:1. Extensive clinical and laboratory investigations failed to reveal any underlying pathology, presence of any underlying disease accompanying the hypergammaglobulinemia and/or plasma cell proliferation.