Composite mycosis fungoides and B-cell chronic lymphocytic leukemia.

Concordant or composite mycosis fungoides and B-cell chronic lymphocytic leukemia (B-CLL) is exceedingly rare, with only 10 cases previously described to our knowledge. We report a case of a 64-year-old woman who developed generalized erythroderma 5 years after the diagnosis of early stage B-CLL. Over the next 6 years of her clinical course multiple sequential samples of skin, peripheral blood, and one enlarged lymph node were studied in detail by flow cytometry, immunohistochemistry, molecular diagnostics, and electron microscopy.