Epidemiology of cutaneous T-cell lymphomas: state of the art and a focus on the Italian Marche region

: Among primary cutaneous T-cell lymphomas (CTCL), mycosis fungoides (MF) is the most frequent and, along with Sézary syndrome (SS), the best-studied subtype. Most available studies on epidemiology of MF and SS are based on small cohorts or different inclusion criteria. Moreover, although this has become a hot topic, most studies show limitations, such as selection bias and lack of clinical information or follow-up data. Therefore, no reliable conclusions can be drawn. This paper reviews the current data underpinning our understanding of the epidemiology of MF and SS, and presents some original findings based on data retrieved from the cutaneous lymphoma registry of the Italian Marche region. The Marche Regional Cutaneous Lymphoma Registry is a multidisciplinary team founded 27 years ago to share the management of these rare disorders. All patients with a clinical and histologically confirmed diagnosis of primary cutaneous lymphoma are centralized in Ancona (Italy) at the Haematology Clinic, Polytechnic University of Marche, for clinical evaluation, staging, treatment, and follow-up. This paper emphasizes the need for a national registry of pCLs in Italy, as no detailed epidemiological information is available in the country except for the Marche Regional Cutaneous Lymphoma Registry. A national registry would allow for more comprehensive data collection from all over Italy and could provide more accurate information on incidence and epidemiology. This would be beneficial for understanding the pathogenesis and diagnostic procedures of these diseases and could improve patient outcomes. Therefore, we advise the creation of a national registry of pCLs in Italy.