Infant With Enlarged Second and Third Toes
Photo Quiz
Self-Test Your Diagnostic Acumen
Infant With Enlarged Second and Third Toes
THE CASE: A male infant was born at term with enlarged, asymmetrical second and third toes on the right foot. Family history was noncontributory. The mother had received adequate prenatal care and had no complications during pregnancy or delivery. Radiographs of the foot demonstrated osseous overgrowth of the bones in the involved digits, with otherwise normal underlying bony structures.
What might explain this anomaly?
A. Proteus syndrome
B. Maffucci syndrome
C. Neurofibromatosis
D. Klippel-Trenaunay-Weber syndrome
E. Isolated macrodactyly
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Photo Quiz–Answer
Infant With Enlarged Second and Third Toes
DISCUSSION: The clinical picture is consistent with isolated macrodactyly, nonhereditary congenital localized gigantism. Although the true cause is unknown, theories about alteration in fetal circulation or lipomatous degeneration have been suggested.1 There are 2 types of isolated macrodactyly: macrodystrophia lipomatosis, the progressive form, and macrodactyly simplex congenita, the static form.1,2 This condition is characterized by excessive mesenchymal growth usually confined to 2 adjacent digits on one side. The overgrowth occurs in the lower extremity, along the distribution of the plantar nerves, more frequently than in the upper extremity, along the distribution of the median nerves. There is no sex predilection.
Other forms of hemihypertrophy or localized overgrowth in the newborn include hemangiomatous or lymphangiomatous malformation, Klippel-Trenaunay- Weber syndrome, Maffucci syndrome, Proteus syndrome, and neurofibromatosis types 1 and 2.3 These can typically be excluded on the basis of physical examination and radiographic findings. In macrodystrophia lipomatosis, the distal ends of the affected digits may have a “mushroom” shape on radiographs.4 CT reveals fat proliferation, and MRI may show excessive unencapsulated fatty tissue.1,4
As the child grows, the malformation may interfere with joint function, vascular supply, and innervation.5 The anomaly may affect activities of daily living, developmental skill acquisition, and the ability to fit into shoes and gloves; it may also cause parental distress regarding appearance. Management most commonly involves surgical correction.5
This newborn was discharged home after an uneventful nursery stay. Follow-up was arranged with an orthopedic surgeon for possible elective surgery in the future.■