Localized gigantism

Discussion

Macrodystrophia lipomatosa is a rare nonhereditary, congenital condition, which is characterized by local gigantism of hands and feet. Progressive proliferation of all mesenchymal elements, with a disproportionate increase in fibroadipose tissue results in macrodactyly and megalodactyly. It usually involves areas of distribution of the plantar and median nerves.1,2 The localized gigantism is almost invariably recognized at birth as in our case, but starts to cause problems as the child grows. There may be difficulty in walking and in performing routine activities, but cosmetics are the main issue concerning the patient requiring consultation with surgeons. This disease is usually unilateral. The growth velocity may differ from digit to digit, and the abnormal growth usually ceases at puberty. The lower limb is more frequently involved than the upper limb. The abnormal area is usually along a specific sclerotome. The second and third digit of the hand and feet are most frequently involved, corresponding to the median nerve and medial plantar nerve supply in the upper and lower limb.3 The etiology of the macrodystrophia lipomatosa remains unclear. As the child grows there may be degenerative changes of small joints and compression of neurovascular structure. Histopathologically, cut sections are rich in adipose tissue sprinkled in a fine lattice like fibrous tissue as in our case.4 Plain radiographs demonstrate abnormalities in both the soft tissues and bony elements. The affected phalanges and metatarsal bones show an increase in width and length, and are often splayed at their distal ends, giving a mushroom like appearance. The articular surface may slant and in late childhood, severe secondary degenerative changes may affect the joints.3 Ultrasound can assess the soft tissue and changes in the nerve. These are better visualized on MRI. A CT is better to evaluate the changes in bone. The differential diagnosis of macrodystrophia lipomatosa includes lymphangiomas, hemangioma, Klippel-Trenaunay-Weber syndrome, neurofibromatosis, proteus syndrome, and fibrolipomatosis.2 Surgical correction is the treatment of choice. The main surgical principle in treating this condition is to improve the cosmetic appearance, and to preserve the neurological function as far as possible.4 Surgery is usually carried out after puberty when growth ceases. Cautious and planned use of multiple debulking procedures, epiphysiodesis, and various osteotomies are recommended to achieve the best results. However, complications associated with overzealous debulking procedure lead to nerve injury with an incidence reported as high as 30-50%. A localized recurrence rate of 33-60% makes the management of macrodystrophia lipomatosa more demanding.

In conclusion, our case is unique as there was a separate swelling at the greater trochanter and proximal leg (not supplied by median and plantar nerves). A proper clinical examination, plain radiography, and ultrasound can diagnose macrodystrophia lipomatosa confidently, thus obviating the need for MRI, especially in a poor socio-economic set up. Amputation with prosthesis can be performed with satisfactory results if the gigantism is very huge and the patient is not ready for multiple debulking surgeries.