Management of Fibrous Hamartoma of Infancy: A Contemporary Series

Fibrous hamartoma of infancy (FHI) is a rare, benign, soft tissue mass that may be locally infiltrative. Primary excision is the mainstay of treatment; however, given the infiltrative nature, margin negativity can be difficult to achieve. The management of residual disease in the setting of positive margins after primary excision is not well described.

All patients undergoing FHI excision from 2012 to 2022 were included. Demographics, operative data, margin status, recurrence, and post-operative follow-up data were obtained via retrospective chart review.

Nine patients were identified who underwent FHI excision. The median age at time of excision was 9 months (IQR 16). Seven (78%) were male, and the majority (78%) were white. Seven (78%) underwent preoperative imaging via ultrasound or MRI, and 4 (44%) had a preoperative biopsy to confirm diagnosis. Common locations included upper extremity (n = 4, 44%) and lower extremity/inguinal region (n = 4, 44%). Six patients (67%) had positive margins on pathology - 3 (33%) on the upper extremity, 2 (22%) on the lower extremity/inguinal region, and one (11%) on the flank. One patient (11%) had a local recurrence which did not undergo re-excision.

FHI remains a rare diagnosis. There is a high margin positivity rate; however, local clinically significant mass recurrence remains uncommon. With low rates of clinically significant mass development coupled with the benign nature of disease, a "watch and wait" approach may be appropriate for patients with positive histologic margins after complete gross excision to avoid reoperation and need for complex reconstructions.

Level 4.