Introduction

Macrodactyly occurs in various settings, but isolated macrodactyly of one or two fingers or toes, especially when it is progressive, is usually due to a fibrolipoma of the sensory nerve proximal to the enlarged digits. Dramatic growth of the digits can cause disfiguration and loss of function, both of which can be minimized by early recognition and management of the syndrome.

Clinical manifestations

Macrodactyly can affect the hand or the foot and typically involves either one digit or two adjacent ones (Fig. 41.1). Bilateral involvement is rare (Amadio et al., 1988). In published reports the fingers are far more likely to be affected than the toes. Digital enlargement is often already present at birth. In some children, the enlarged digit does not seem to grow faster than the other digits, or it expands so slowly that the growth may not be obvious. In other individuals, the digits grow at an alarming rate, causing serious disfigurement and sometimes impairing the function of entire hand or foot. Adjacent enlarged digits tend to curve away from one another (Fig. 41.1), probably because of unbalanced growth of one side of the digits' growth plates.

Some patients have a palpable mass, but in most children with macrodactyly the nerve abnormality is apparent only at surgery. Most patients with a fibrolipomatous hamartoma of a nerve do not develop macrodactyly. In one pathology-based series of 26 individuals, for example, only seven had macrodactyly (Silverman & Enzinger, 1985).