Bullae on the legs of an elderly man. Mycosis fungoides bullosa.

REPORT OF A CASE A 92-year-old white man, previously diagnosed with mycosis fungoides, was referred for evaluation of an increasing number of pruritic erythematous patches and plaques on his body and a 1-week history of bullous lesions on his lower legs. He had been seeing a hematologist for his chronically elevated leukocyte count and a few circulating Sezary cells since his diagnosis of mycosis fungoides 10 years earlier. His treatment included nitrogen mustard ointment applied three times per week and clobetasol propionate applied nightly. Physical examination revealed a well-nourished elderly man with widespread erythematous patches and plaques on his trunk, arms, and legs ( Figure 1 ). On the lower legs were flaccid bullae filled with clear fluid and superficial erosions ( Figure 2 ). No adenopathy or hepatosplenomegaly was detected. Laboratory studies revealed the following values: hemoglobin, 120 g/L; leukocytes, 13.7×10 9 /L with normal differential; and platelets, 448×10 9 /L. Blood film