Annular Scaly Plaque on the Left Foot: Challenge

Risk of mycosis fungoides in psoriatic patients: a critical review

“…Thirty‐six articles were excluded because they were either reporting generic data, unspecific reviews or comments, generic case series or case reports without detailed data regarding psoriasis treatments, outcome or histology. Thirty‐five articles were eligible for this review . They were grouped and analysed in works describing the risk for psoriatic patients to develop lymphoma overall (see Table ), works reporting the risk for psoriatic patients to develop CTCL/MF or T‐NHL (see Table ) and case reports of psoriatic patients who developed MF after systemic or biological therapy for psoriasis (see Table ).…”

“…Regarding the risk of developing MF in psoriatic patients, the above-mentioned studies [14][15][16][17][46][47][48][49] (Table 2) present some bias and limitations, the misclassification process between psoriasis and MF being the fundamental issue. Early-stage MF may simulate many inflammatory dermatoses including psoriasis, 4,50,51 and diagnosis of MF can be made only upon detailed clinicopathological correlation. 1,2 Moreover, reasonably often, early MF diagnosis cannot be confirmed at the first biopsy; rather, multiple biopsies at follow-up visits are needed.…”

“…14 Regarding misclassification bias in the case reports of MF onset after systemic treatment for psoriasis, it should be underlined that MF may simulate psoriasis both clinically (erythematous scaling patches) and histopathologically. 2,4,19,50 In fact, psoriasis and early MF may share some histopathological features such as epidermal hyperplasia and exocytosis of lymphocytes and CD4 + T cells in the dermal infiltrate. 51,65,68 Considering the small series of patients reported in the literature (Table 3), after histology seven cases were confirmed to be truly affected by both diseases rather than by a misclassification process, confirming that indeed, the onset of MF in psoriasis may occur, but is a rare event.…”

“…Regarding misclassification bias in the case reports of MF onset after systemic treatment for psoriasis, it should be underlined that MF may simulate psoriasis both clinically (erythematous scaling patches) and histopathologically . In fact, psoriasis and early MF may share some histopathological features such as epidermal hyperplasia and exocytosis of lymphocytes and CD4 + T cells in the dermal infiltrate .…”