A range of histologic findings in infantile digital fibromatosis

Infantile digital fibromatosis is a benign proliferation of myofibroblasts with characteristic eosinophilic intracytoplasmic inclusion bodies. Clinically, patients present in the first several years of life with asymptomatic, smooth, flesh-colored nodules located on the dorsal or lateral aspect of the fingers or toes. The lesions have a tendency for spontaneous regression and recur over 60% of the time following excision. Observation is often recommended, while surgery is reserved for cases of rapid growth or functional impairment. We report three patients, ranging in age from 8 months to 8 years, with infantile digital fibromatosis. All three patients presented with nodules on the hands or feet and all shared histologic findings of spindle cells with characteristic inclusion bodies. Pathologic features ranged from a haphazard arrangement of spindle cells with few inclusion bodies and numerous lymphocytes to a well-organized arrangement of spindle cells with abundant inclusion bodies and rare lymphocytes. All three patients underwent excision for diagnosis or treatment of their tumors with two of the patients experiencing a recurrence.