Unilesional interstitial mycosis fungoides: a case report

A 42-year-old man presented with a slowly spreading,asymptomatic,infiltrated erythematous patch in the fight side of the chest and back for more than half a month.Dermatologic examination revealed a poorly marginated,pink infiltrated patch sized 5 cm × 7 cm in the right subscapular region of the back and chest.Histopathologically,there was an infiltrate of numerous mononuclear cells in the superficial dermis as well as between collagen fibers in the middle and deep dermis,with epidermotropism of some cells and formation of Pautrier's microabscesses.Mild atypia was observed in some infiltrating mononuclear cells.Immunohistochemistryshowed that the mononuclear cells were positive for CD3,CD4 (scattered),CD5,CD8,CD45Ro,the cytotoxicgranule-associated protein TIA-1,but negative for CD7,CD20,CD30,CD56,CD68,CD79α,and granzyme B,with the percentage of Ki-67-positive cells higher than 20％.T cell receptor (TCR) rearrangement was negative.The final diagnosis was unilesional interstitial mycosis fungoides. Key words: Mycosis fungoides;  Case reports [Publication type]