CD30-Positive Anaplastic Lymphoma Kinase-Negative Systemic Anaplastic Large-Cell Lymphoma in a 9-Year-Old Boy.

Anaplastic large-cell lymphoma (ALCL) is a CD30-positive T-cell/null-cell lymphoma that is clinically classified into either primary cutaneous ALCL or systemic ALCL (S-ALCL) sub-types. Because 90% of childhood S-ALCL cases are anaplastic lymphoma kinase (ALK)-positive, there is a lack of data on ALK-negative S-ALCL cases among pediatric patients. Herein, we report a rare case of ALK-negative S-ALCL in a 9-year-old Korean boy who initially presented with itchy erythematous maculopapules and an erosive nodule on the trunk area. We emphasize the need of high index of suspicion of an underlying malignant disease in the presence of refractory eczematous lesions.