Fibrous hamartoma of infancy. Radiologic-pathologic study of 21 cases: 8 with predominant pseudoangiomatous pattern

Fibrous hamartoma of infancy (FHI) is a very rare benign soft tissue lesion that principally affects the axilla, trunk, and upper extremities of children younger than 2 years. It is usually cured by local excision. Histologically, these lesions have a triphasic morphology in an organoid pattern: mature adipose tissue, fibroblastic/myofibroblastic trabeculae, and small round cell nests in a myxoid matrix. However, morphologic variants have recently been described. Focal areas with a pseudoangiomatous pattern have been found in some FHI, but few cases with predominant pseudoangiomatous areas have been previously described in the medical literature. We report 21 new cases of FHI, 8 of them with a predominant pseudoangiomatous pattern. Our cases with a predominant pseudoangiomatous pattern did not present specific radiological findings.