Fibrous hamartoma of infancy (FHI) is a rare benign soft tissue tumor of early childhood, often misdiagnosed due to its clinical and/or radiological resemblance to vascular malformations or pediatric soft tissue neoplasms.

A 7-month-old male presented with a rapidly enlarging, firm, non-pulsatile subcutaneous mass involving the anterior aspect of almost the entire right arm. MRI suggested a low-flow vascular malformation; however, due to clinical concern for alternative pathology and the lesion's benign appearance, large size, superficial location, and resectability, complete excision was performed. Histopathology revealed the characteristic triphasic pattern confirming fibrous hamartoma of infancy. The patient recovered well with no recurrence at 3-month follow-up.

This case highlights the diagnostic pitfalls of FHI, which may closely mimic vascular anomalies on imaging, and underscores the importance of surgical excision for both definitive diagnosis and curative treatment. To our knowledge, this represents the first reported case of FHI from Palestine.

L.J.M.S.: supervision, writing—original draft, writing—review and editing; M.I.M.: writing—original draft; I.A.B.: writing—review and editing; J.S.: supervision, writing—review and editing.

Received: 06 October 2025

Accepted: 15 January 2026

Article published online:
31 January 2026

© 2026. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution License, permitting unrestricted use, distribution, and reproduction so long as the original work is properly cited. (https://creativecommons.org/licenses/by/4.0/)

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