Solitary, Enlarging Painful Violaceous Tumor on the Cheek of a 10-Year-Old—Diagnosis

Microscopic findings showed a diffuse monomorphic population of lymphoid cells with hyperchromasia and large nucleoli. Lesional cells were positive for PAX5, CD79a, CD10, terminal deoxynucleotidyl transferase, CD43, and BCL2. Cells were negative for CD20, CD2, CD3, CD4, CD5, CD7, CD8, cyclin D1, ALK1, CD30, MUM1, BCL6, lysozyme myeloperoxidase, CD34, CD1a, and CD99. Colloidal iron and periodic acid–Schiff stains were negative for dermal mucin and fungal microorganisms, respectively (Figure 2).