[An indolent and fluctuating subcutaneous mass of the skull in a 5-year-old patient: Diagnostic approach and difficulties]. / Une masse indolente et fluctuante sous-cutanée du crâne chez une patiente de 5 ans : démarche et difficultés diagnostiques.

A subcutaneous mass of the skull in children can have many different causes (infectious, tumoral, and inflammatory). We report on the case of a 5-year-old patient with a subcutaneous mass of the skull evolving over several months. The first pathological analysis concluded in Kimura disease. The progression and scarcity of this entity in children led to a second pathological analysis that showed lymphoblastic lymphoma B (LLB). This case reminds us that when there are discrepancies between pathological conclusions and clinical progression of a tumoral process, repeated analysis and immunochemistry are necessary.