Macrodystrophia Lipomatosa with Median Nerve Involvement

Introduction: Macrodystrophia Lipomatosa (MDL) is a rare cause of congenital macrodactyly, characterized by progressive proliferation of all mesenchymal elements, with a disproportionate increase in fibro-adipose tissue. This developmental anomaly is reportedly more common in the foot than in the hand, with a predilection for the plantar and median nerve distribution.

Clinical History: A 25 year old female presented with history of enlargement of middle and ring finger since childhood. She had undergone surgery for the same in childhood. History of painful swelling over volar part of the wrist was noted past 4 to 5 months, because of which she was referred for MRI.

Imaging findings:

  • Diffuse enlargement and hypertrophy of the median nerve with fatty proliferation, measuring 1.2 cm in maximum thickness. (cause of swelling)
  • Splaying of third and fourth digits at their distal ends.
  • Fibro-fatty proliferation of deep subcutaneous fat around the phalanges of third and fourth digits, showing fat signal intensity on all sequences.
  • Expansion of medullary cavity of the phalanges of third digit.
  • The terminal phalanges of third and fourth digits are not visualized (history of surgery noted).