Peripheral nerve entrapment due to steroid-induced lipomatosis of the popliteal fossa. Case report

Adipose lesions of nerve: the need for a modified classification

OBJECT

Adipose lesions of nerve are rare and poorly understood. Their current classification, although not universally accepted, generally includes lipomatosis of nerve with or without localized macrodactyly, and intra- as well as extraneural lipoma. The authors believe that the spectrum of these lesions and their interrelationships are not currently appreciated. They propose an adaptation to the existing framework to illustrate the expanding spectrum of adipose lesions of nerve by considering lipomatosis and lipoma singly or in combination.

METHODS

Fourteen representative cases are presented to demonstrate not only the intraneural and extraneural examples of lipomatosis and lipoma, but also their anatomical combinations.

RESULTS

Based on the cases presented and a careful literature review, a conceptual approach to the classification of adipose lesions of nerve is generated. This approach incorporates the 2 essential lesions, lipomatosis of nerve and lipoma, in both their intra- and extraneural forms. This permits expansion to encompass combinations.

CONCLUSIONS

To press the concept that adipose tumors of nerve are a broad but interrelated spectrum of lesions, the authors propose modification of the present classification system. This approach provides an orderly platform for progress, reflects understanding of these interrelated lesions, and facilitates optimal treatment by distinguishing resectable from nonresectable components.

Lipoma compressing the brachial plexus in a patient with sarcoidosis: case report

Lipomas associated with distal peripheral nerves are well recognized; however, those impinging on the brachial plexus are rare. We document a unique case of a sarcoidosis patient with an extraneural lipoma compressing the brachial plexus, and present a review of the current literature.

Nonoccupational risk factors for carpal tunnel syndrome

OBJECTIVE

To examine the relation between selected nonoccupational risk factors and surgery for carpal tunnel syndrome.

DESIGN

Case-control study using an administrative database.

PARTICIPANTS

Enrollees of New Jersey Medicare or Medicaid programs during 1989 to 1991.

MEASUREMENTS

The outcome of interest was open or endoscopic carpal tunnel release. We examined the relation between carpal tunnel release and diabetes mellitus, thyroid disease, inflammatory arthritis, hemodialysis, pregnancy, use of corticosteroids, and hormone replacement therapy.

MAIN RESULTS

In multivariate models, inflammatory arthritis was strongly associated with carpal tunnel release (odds ratio [OR] 2.9; 95% confidence interval [CI] 2.2, 3.8). However, corticosteroid use also appeared to be associated with a greater likelihood of undergoing carpal tunnel release, even in the absence of inflammatory arthritis (OR 1.6; 95% CI 1.2, 2.1). Diabetes had a weak but significant association with carpal tunnel release (OR 1.4; 95% CI 1.2, 1.8), as did hypothyroidism (OR 1.7; 95% CI 1.1, 2.8), although patients with hyperthyroidism did not have any change in risk. Women who underwent carpal tunnel release were almost twice as likely to be users of estrogen replacement therapy as controls (OR 1.8; 95% CI 1.0, 3.2).

CONCLUSIONS

Although inflammatory arthritis is the most important nonoccupational risk factor for carpal tunnel release, these data substantiate the increase in risk associated with diabetes and untreated hypothyroidism. Further investigation in detailed clinical studies will be necessary to confirm whether changes in corticosteroid use and hormone replacement therapy offer additional means of risk reduction for this common condition.