Skin involvement as the first symptom of rapidly progressive ALK-positive systemic anaplastic large cell lymphoma

Systemic anaplastic large cell lymphomas (sALCLs) comprise a heterogeneous group of relatively rare T-cell non-Hodgkin lymphomas that are characterized by CD30 expression. Anaplastic lymphoma kinase (ALK)-positive ALCL is a type of sALCL that commonly involves lymph nodes and extranodal sites. Skin involvement usually presents as tumours, nodules and ulcers. We describe an unusual case of ALK-positive ALCL in an 11-year-old Chinese boy, who initially presented with skin eruption with rapid progression and poor prognosis. This case emphasizes the value of clinical factors to predict the prognosis of ALK-positive sALCL, and we recommend close collaboration between dermatologists, pathologists and haematologists/oncologists to assure the correct diagnosis and treatment.