Risk of mycosis fungoides in psoriatic patients: a critical review

Abstract

Psoriasis has been controversially associated with risk of non-Hodgkin lymphoma (NHL) and mycosis fungoides (MF). Also patients who developed MF after systemic treatment for psoriasis have been reported, and some authors suggested that the association between MF and psoriasis is not infrequent. We performed an extensive literature review in order to examine the risk of developing MF in psoriatic patients with a systematic search of the English-language databases. An increased risk for lymphoma overall in psoriatic patients has been found only by three out of seven studies. The risk of developing MF in psoriatic patients has been investigated by different studies in different populations and with different methodologies presenting bias and limitations, and it seems reasonable that misclassification between psoriasis and MF may explain the association reported. In contrast to the large number of psoriatic patients treated with biologicals, only 27 case reports of MF after biological therapy for psoriasis have been reported, and in 10 cases, the initial psoriasis diagnoses were then revised as MF. A true association between MF and psoriasis is possible, but the real incidence and prevalence are still unknown. The reported higher risk of developing MF in psoriatic patients should be reconsidered in the light of the bias of misclassification and the low magnitude reported in previous studies. There is not enough evidence to support a causal relation among biological therapies and MF in psoriatic patients.

Understanding the enigmatic association between mycosis fungoides and psoriasis: Report of two cases and review of the literature

“…Apart from the characteristic features of MF, histologic features of psoriasis, such as elongation of the rete ridges with regular acanthosis, hyperkeratosis with parakeratosis, thinning, or total effacement of the granular layer and Munro microabscesses are present. Overall, it appears reasonable that misclassification between the two disease entities, psoriasis and MF, could explain the strong associations between psoriasis and CTLC observed in the literature [ 2 ].…”

“…MF has been characterized as a “dermatological masquerader” due to its multiple clinical variants, such as folliculotropic, poikilodermatous, hypopigmented, capillaritis-like, verrucous/hyperkeratotic, psoriasiform, ichthyosiform and bullous. In its erythrodermic form, the differential diagnosis between eczema or psoriasis and MF is virtually impossible based on clinical appearance [ 1 , 2 ].…”

“…Psoriasis is one of the commonest chronic dermatoses, with approximately 2–3% of subjects affected worldwide, presenting with erythematous scaly plaques that can be clinically indistinguishable from psoriasiform MF [ [2] , [3] , [4] , [5] , [6] , [7] , [8] , [9] , [10] , [11] , [12] ]. Psoriasis, a chronic immune-mediated inflammatory disorder, has been linked to a moderately higher risk of certain malignancies, particularly keratinocyte, lung, urinary/bladder, oropharynx/larynx, hepatic and colorectal cancers as well as lymphomas [ 2 , 13 , 14 ].…”

“…A very recent collaborative analysis of 12 European registries has shown that although the subtype of lymphoma distribution differed between RA and the general population, there were no differences in the distribution of lymphoma subtypes in patients with RA treated with Tumor Necrosis factor-alpha (TNF-α) inhibitors compared with bio-naïve patients [ 22 ]. The association between psoriasis and lymphoma has also been discussed [ 2 , 14 , 23 , 24 ]. Two large population-based studies have shown that the incidence rates for Hodgkin lymphoma, non-Hodgkin lymphoma and CTCL were higher among patients with psoriasis compared with the general population [ 23 , 24 ].…”

A Comprehensive Update of the Atypical, Rare and Mimicking Presentations of Mycosis Fungoides

“…The annual incidence varies between 0.3 and 0.96 cases per 100,000 persons [9], typically affecting patients between 45 and 65 years of age, with a male to female sex ratio of 2:1. Childhood and adolescent MF cases are more exceptional [10][11][12][13][14][15][16].…”