INFANTILE DIGITAL FIBROMA (FIBROMATOSIS)
Tumors of this type usually occur in infants or young children, and most occur on the hands or feet. Multiple lesions are present in some cases. These have a pronounced tendency to recur, but they are benign. Some are associated with functional impairment, but most are asymptomatic. Instances of spontaneous regression have been reported, and it has been suggested that observation rather than surgery be tried. One function of the pathologist or dermatopathologist is to calm the family and surgeon in the face of a growing or recurring mass.

The tumor is composed of a fibrous mass that usually occupies most or all of the dermis. Intracytoplasmic eosinophilic inclusions within fibroblasts or myofibroblasts are the diagnostic feature. Such structures may be found in an apparent extracellular location, but these may actually be within fibroblasts cut in cross-section. Their nature has been debated. These vary in number from case to case. I can recall one child who had  inclusions in the initial resection, none demonstrable in the first recurrence, and  demonstrable inclusions in the second recurrence.
 
 
One dominant nodule with a smaller similar papule just dorsal to it. Low power showing a fibrous mass extending from the epidermis (left upper corner) into the base of the specimen.

 
 
High power showing intracellular inclusions (center arrows) and an apparent extracellular inclusion (left arrow). You have to hunt for these with some diligence in many cases. Oil immersion magnification showing the intracellular inclusions.

Click on your browser's 'Back' button to go to the previous page.