Miyashiro D, Sanches JA, et al. - In comparison to the literature, the authors found a higher percentage of hypopigmented mycosis fungoides (MF), as well as demographic (older age) and prognostic (poorer prognosis) similarities between erythrodermic MF and Sézary syndrome (SS), implying a possible relationship between these erythrodermic lymphomas. Factors linked to a poorer prognosis were consistent with the literature.

• Between 1989 and 2018, MF/SS patients assessed at the University of São Paulo Medical School were involved.

• MF was diagnosed in 92.6% (673) of the 727 patients, while SS was diagnosed in 7.4% (54) of the patients.

• The sample consisted of 372 males (51.2%) and 355 females (48.8%).

• The median age was 51.8 years; which was higher in erythrodermic MF (60.2) and SS (60.9).

• Among those with MF, 41.8% (281) had classic MF, 4.9% (33) folliculotropic MF, 1.8% (12) granulomatous slack skin, and 0.3% (2) pagetoid reticulosis.

• Erythrodermic, hypopigmented, and poikilodermatous MF were all common subtypes.

• Extracutaneous involvement was uncommon.

• Five, 10, 20, and 30-year overall survival rates for early-stage were 97.3%, 92.4%, 82.6%, and 82.6%, respectively, and 58.6%, 42.7%, 20.8%, and 15.4% for advanced-stage disease.

• Following multivariate analysis, SS diagnosis, folliculotropic MF, erythrodermic MF, clinical stage, age (≥ 60 years), increased lactate dehydrogenase, and large cell transformation were associated with a worse prognosis.