Reye Tumor

Reye tumor, more properly called inclusion body fibromatosis, is also known as digital neurofibrosarcoma, infantile digital fibromatosis, infantile dermal fibromatosis, infantile digital fibroma, infantile dermal fibroma, infantile digital myofibromatosis, and digital fibrous tumor of infancy and childhood.

These dome-shaped nodules involve the extensor surfaces of the distal or middle phalanges of the fingers (more common) and toes. They have a preference for the ulnar-sided and lateral digits in the hand and foot, respectively. The majority are diagnosed in the first year of life (about 1/3 are congenital).

There may be a nonspecific soft-tissue mass on radiographs. US, CT, and MRI of inclusion body fibromatosis is also nonspecific: a heterogeneous, poorly marginated, subcutaneous soft-tissue mass similar to other superficial fibromatoses.

References

Murphey MD, Ruble CM, Tyszko SM, Zbojniewicz AM, Potter BK, Miettinen M. From the archives of the AFIP: musculoskeletal fibromatoses: radiologic-pathologic correlation. Radiographics. 2009 Nov;29(7):2143-73.