[Infantile myofibroma: a neonate with a swelling on the arm]

Abstract

Background: An infantile myofibroma (IM) is a benign congenital soft-tissue 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 full-term neonate presenting with an irregular tumour mass on the right lower-arm. 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 characteristics alone due to the heterogeneous presentation. A definitive diagnosis can only be made following histological investigation.