Mycosis fungoides (MF), is considered rare in children and adolescents. Accumulating experience indicates that compared to adult MF, almost all paediatric MF patients are diagnosed at an early-stage disease, exhibits higher rates of atypical presentations, and follow a notably indolent course. Despite the need for special staging/workup and treatment-related safety considerations specific for children and adolescents, the staging of paediatric MF is currently based primarily on standard practice in adults.
To develop staging recommendations on behalf of the 3 largest societies for cutaneous lymphomas, the ISCL, EORTC, and USCLC, specifically designed for MF in children and adolescents.
The guideline was developed through an international expert consensus process and in accordance with the EQUATOR Network's recommendations for guideline development. A modified Delphi process was conducted, using questionnaires covering topics including the definition, characteristics, and staging of paediatric MF. Two rounds of expert feedback were conducted, with an additional one hybrid consensus meeting.
A consensus was reached that the term paediatric MF should be reserved for MF diagnosed at ≤18 years. Panelists specified the unique clinical characteristics of paediatric MF, including a high prevalence of hypopigmented and folliculotropic variants, and reached a consensus on the indolent nature of the disease during childhood and adolescence with rare progression to advanced stage. The consensus reached recommends that while staging approach is largely similar to that in adults, imaging for early- stage paediatric MF should rely on ultrasound of the lymph nodes if indicated, rather than CT/PET-CT. Clinicians should be aware that in children palpable lymph nodes are common, owing to the increased incidence of infectious diseases.
This guideline addresses the major clinical characteristics of paediatric MF, which differ from those in adults, and provides practical staging recommendations considering the safety implications specific for this age group.