A Case of Vesicular Mycosis Fungoides

A 44-year-old male presented with 7 months history of nonpruritic round oozing plaques on the extremities and red papules on the trunk. The lesions were resistant to topical and oral steroid prescribed at the other local clinics. Histopathological examination showed parakeratosis with acanthosis and rete ridge elongation as well as spongiotic intraepidermal blisters and dense dermal infiltration of small to medium sized atypical lymphoid cells. Immunohistochemical analysis revealed the lymphocyte infiltrate to be predominantly CD4⁺ T cells, with CD4/CD8 ratio to be greater than 10:1. Infiltration of large cells that were CD30⁺ were also noted. This histopathologic findings are consistent with vesicular mycosis fungoides (MF). He was prescribed with narrow-band ultraviolet B twice per week and topical steroid, combined with interferon-α injection for 5 weeks, and his skin lesions significantly faded and were flattened. Vesicular MF is associated with poor prognosis, but our patient was able to show benign course of disease thanks to timely diagnosis. One must consider vesicular MF as a differential for recalcitrant eczematous lesions.