Macrodystrophia lipomatosa is a rare form of localised gigantism, and many terms have been used interchangeably, with resulting confusion. They include macrodactyly, megalodactyly, digital gigantism, macromelia, partial acromegaly, macrosomy, and limited gigantism 3.
It is worth noting that macrodystrophia lipomatosa is essentially analogous to static localised gigantism (as descrbed by Barsky in 1967) 3.
Macrodystrophia lipomatosa is congentital but non-hereditary, and is usually identified in the neonatal period 3.
This condition typically presents with a painless enlargement of the 2nd or 3rd digit of the hand or foot. It is usually unilateral but may involve adjacent digits in the distribution of the median or plantar nerves. Occasionally it involves the entire limb 3.
Macrodystrophia lipomatosa is characterised by a marked increase all mesenchymal elements 1. This is dominated by adipose tissue in a fine fibrous network involving periosteum, bone marrow, nerve sheath, muscle, and subcutaneous tissue.
Recognised associations include:
Plain films usually suffice, and demonstrate splayed, lengthened and broadened phalanges with endosteal and periosteal bone deposition.
The overlying soft tissues are markedly overgrown, especially in the volar and distal aspects. Within the soft tissues focal lucent areas representing fat may be seen, which is characteristic.
MRI is helpful in distinguishing macrodystrophia lipomatosa from other causes of macrodactyly (see below). It demonstrates accumulation of fat in the subcutaneous tissues without a discernable capsule 1.
Treatment and prognosis
Although macrodystrophia lipomatosa is considered a progressive form of macrodactyly (i.e. the growth of the affected parts is faster than the rest of the body) growth halts at puberty 4.
As such treatment is reserved for cosmesis and when mechanical function is impaired.
- neurofibromatosis type 1 (NF1)
fibrolipomatous hamartoma of the median or ulnar nerve
- fatty tissue accumulates within the nerve sheath rather than within the region 1
- vascular malformation
- chronic hyperaemia
- Russell-Silver dwarfism
History and etymology
The term was first coined in 1925 by Feriz 3.
- 1. Blacksin M, Barnes FJ, Lyons MM. MR diagnosis of macrodystrophia lipomatosa. AJR Am J Roentgenol. 1992;158 (6): 1295-7. AJR Am J Roentgenol (citation) - Pubmed citation
- 2. Murphey MD, Carroll JF, Flemming DJ et-al. From the archives of the AFIP: benign musculoskeletal lipomatous lesions. Radiographics. 24 (5): 1433-66. doi:10.1148/rg.245045120 - Pubmed citation
- 3. Khan RA, Wahab S, Ahmad I et-al. Macrodystrophia lipomatosa: four case reports. Ital J Pediatr. 2010;36 : 69. doi:10.1186/1824-7288-36-69 - Free text at pubmed - Pubmed citation
- 4. Castriota-Scanderbeg A, Dallapiccola B. Abnormal Skeletal Phenotypes. Springer. ISBN:3540679979. Read it at Google Books - Find it at Amazon