Background: Fibrous hamartoma of infancy is a benign mesenchymal tumor occurring infrequently in children, typically involving the axilla.
Case Report: An 18-month-old girl with a history of right labium majus enlargement, on examination, had a hard mass that was found strictly adherent to subcutaneous tissue and overlying skin. Postexcision histological examination showed arranged spindle cells, adipose tissue, and nests of immature small cells in a myxoid background, consistent with fibrous hamartoma of infancy.
Conclusions: The main problem in the diagnosis is differentiating this lesion from soft tissue sarcomas, which require an aggressive therapeutic approach. Both surgeons and pathologists need to be aware of the existence of such benign condition in this unusual place to avoid unnecessary therapies.