Infantile Digital Fibromatosis (Inclusion Body Fibromatosis) Observed in a Baby Without Finger Involvement

A 9-day-old male baby was hospitalized after his birth due to some swells under the skin. The hard consistency nodules observed under the skin all over the body of the patient were of different size, and presented lesions, among which the biggest was 1 × 1 cm. No lesions were observed on the fingers. By superficial ultrasonography, multiple isoechoic hypoechoic lesions were observed among the muscle plan. In thoracolumbar magnetic resonance imaging, multiple massif lesions retaining peripheral contrast (the biggest was 1.7 × 1.4 cm large) had been observed under the skin muscle plans, between the muscles of the extremities. The biopsy was positive for smooth muscle actin, but negative for desmin, S100, and CD34. These findings were diagnosed as infantile digital fibromatosis (IDF) (inclusion body fibromatosis). The case was presented with an objective to illustrate and remind that IDF can be observed in babies without finger involvement.