Mycosis Fungoides Palmaris et Plantaris Mimicking Palmoplantar Pustulosis: A rare case report

Atypical presentations of cutaneous T-cell lymphoma can mimic common inflammatory skin disorders, posing significant diagnostic challenges.Palmoplantar involvement is uncommon, and mycosis fungoides palmaris et plantaris (MFPP) presenting with pustular lesions resembling palmoplantar pustulosis (PPP) is even rarer. 1To date, only two cases of MFPP with PPP-like manifestations have been reported. 2,3Here, we report an additional case presenting with PPP-like lesions that responded well to treatment.A 69-year-old woman had a 10-year history of erythema and vesicles on her right palm, some progressing to pustules with pruritus and scaling.Four years ago, similar lesions appeared on the left palm, accompanied by bilateral hand edema, with lesions strictly confined to the palms and no involvement of the feet (Figure 1a).She was repeatedly hospitalized and initially misdiagnosed with eczema, receiving topical and systemic therapies with limited effect.Eight months prior, an external biopsy reportedly showed pseudoepitheliomatous hyperplasia with intraepidermal blister formation, and histopathology described spongiotic dermatitis with prominent lymphocytic infiltration and epidermal edema.The original slides were unavailable, and subtle features of mycosis fungoides may have been overlooked, so no definitive diagnosis was made.One month before admission, the lesions worsened, manifesting as diffuse erythema, pustules, scaling, and edema on both hands, more pronounced on the right.She was admitted with a provisional diagnosis of PPP.Laboratory tests, including complete blood count, liver and renal function, urinalysis, stool exams, coagulation studies, and immunological assays, were normal.A comprehensive microbiological work-up of the hand lesions, including bac-