Het infantiel myofibroom: Een neonaat met een gezwel van de onderarm

Background: An infantile myofibroma (IM) is a benign congenital softtissue tumour. IM is found in 1 per 150,000 live births, making it the most common fibrous tumour of infancy and early childhood. Case description: We report on a fullterm neonate presenting with an irregular tumour mass on the right lowerarm. The mass measured 5 cm in diameter, with surface ulceration. Magnetic resonance imaging (MRI) revealed characteristics that could be consistent with malignancy. On the basis of a biopsy and subsequent polymerase chain reaction we were able to make a diagnosis of 'benign infantile myofibroma'. We chose for conservative treatment in the expectation that the tumour would regress spontaneously. Conclusion: Infantile myofibroma should be considered when a newborn presents with an atypical mass. It is difficult to make a diagnosis on the basis of the clinical characteristicsalone due to the heterogenous presentation. A definitive diagnosis can only be made following histological investigation.