To the Editor: Eighteen days after hepatobiliary iminodiacetic acid (HIDA) scintigraphy, an 81-year-old woman presented with pruritic, painful, discrete, tender papules in a generalized distribution (Fig 1). She noted onset of the eruption shortly after the HIDA scan. Biopsy specimen of 2 papules from the right thigh showed an infiltration of mitotically active lymphocytes (Fig 1, top inset) confined to the upper dermis. The lymphocytes were predominantly CD3+ T cells; occasional scattered CD20+ B cells were present. CD4 and CD8 were present in an approximately 2:1 ratio, and both cell types were noted within the epidermis. Small aggregates of large CD3+/CD30+ lymphocytes were present, comprising less than 25% of the lymphoid population (Fig 1, bottom inset). The histopathology and immunostaining supported a diagnosis of CD30+ plasma cell dyscrasia (pseudolymphoma).