Sézary syndrome without erythroderma: A case report and review of published work.

Sézary syndrome (SS) is defined by erythroderma and circulating atypical T cells, with or without lymphadenopathy. Recently, Thompson et al. identified a distinct population of SS patients with an atypical presentation: a high blood tumor burden of Sézary cells fulfilling criteria for SS but without fulfilling the criteria for erythroderma at the diagnosis. Here, we report a case of a 49-year-old Japanese man with SS who did not present with erythroderma initially, but exhibited erythematous itchy papules symmetrically located on the legs and arms. We also reviewed reported cases of SS without initial erythroderma. The skin manifestations at diagnosis varied from patches to tumors often seen in mycosis fungoides, and other rarer findings such as excoriation, palmoplantar keratoderma and alopecia. Pruritus was reported in most patients (86%), unlike early mycosis fungoides, and could be the main clue to the diagnosis of SS. Notably, three patients were reported to have presented with papular lesions, similar to our case. Little is known about why skin lesions in SS without erythroderma vary and why these cases did not exhibit erythroderma initially. Attenuated stimulation by colonized Staphylococcus aureus, impairment in recruitment of malignant T cells and suppression of inflammatory response induced by malignant T cells with regulatory phenotype may be associated with skin manifestations. Further studies are necessary to elucidate the etiology of this entity.