Subdermal fibrous hamartoma of infancy in the hand.Scand J Plast Reconstr Surg Hand Surg. 2007; 41(4):211-4.

A fibrous hamartoma of infancy presented in a 4-month-old girl as three separate masses on her right hand. Magnetic resonance imaging showed that the lesions had indistinct margins, and were infiltrating to the overlying subcuticular layer; there was pathological contrast enhancement and high signal intensity in the bony medulla. The masses were successfully excised. The radiological and physical appearance of fibrous hamartomas in a child may suggest malignancy, but the lesion is typically benign and treatment by local excision is usually successful.

Cutaneous changes in fibrous hamartoma of infancy.J Cutan Pathol. 2007 Jan;34(1):39-43.

BACKGROUND: Fibrous hamartoma of infancy (FHI) is a fast growing soft tissue tumor that usually arises in the first 2 years of life. The histology of the lesion has been well described. Few studies, however, have looked at changes in the overlying skin and its appendages. METHODS: A database search performed at British Columbia Children's Hospital yielded 15 cases of unequivocal FHI occurring in 12 patients (three were recurrences). Of these, we were able to retrieve 13. Five of 13 cases had sections including epidermis. These slides were reviewed with specific emphasis on skin adnexae. RESULTS: Of the cases with excised epidermis in continuity with the lesion, 5/5 had eccrine changes, including hyperplasia, duct dilatation, intraluminal papillary formations, and squamous syringometaplasia. One case showed epidermal basaloid follicular hyperplasia. CONCLUSIONS: This study shows that eccrine changes are frequently seen in cases of FHI when overlying skin is sampled. This may be a useful clue to consider this diagnosis, especially when the biopsy is superficial.