Abstract
A 6-month-old boy, a 9-month-old girl, and a 10-month-old boy were admitted to our hospital for a painless and hard mass located in the axilla or upper arm; the tumors were 1.5, 5, and 3cm in size, respectively. In 2 of these cases, the tumors gradually enlarged during the follow-up periods. Tumor resection was performed in all cases, and the histological diagnosis was fibrous hamartoma of infancy (FHI). FHI is a rare tumor arising from the subcutaneous tissue during infancy. Microscopic examination revealed that the tumor consisted of fibrous trabeculae, mature adipose tissue, and immature mesenchymal cells. Preoperative diagnosis was difficult, but magnetic resonance imaging (MRI), especially fat-suppression MRI, proved beneficial in attaining the diagnoses of FHI. Although recurrences of FHI after surgery have been reported, repeated tumor resection is associated with good prognosis.
