Gaucher's disease

(Phillippe Charles Ernest Gaucher, 1854 - 1918, French physician), an autosomal recessive disorder of cerebroside metabolism characterized by accumulation of abnormal amounts of lipid in reticuloendothelial cells and accumulation of these Gaucher cells in various body tissues. For a general description, see Gauchers disease.

Three clinical forms of Gaucher's disease are distinguished. Type 1 is a chronic non-neuronopathic form, most frequent in Ashkenazic Jews. Type 2 is an acute neuronopathic disease, involving a fatal neurodegenerative disorder. Type 3 is a subacute neuronopathic (juvenile) form with neurologic and skeletal manifestations appearing in childhood or adolescence.

On radiographs, infiltration of the bone marrow with Gaucher cells is characterized by increased radiolucency of bone and cortical scalloping and thinning. Geographic or motheaten patterns of bone destruction may be seen in focal osteolytic lesions. The spine may show osteopenia or osteolysis of the vertebral bodies, multiple compression fractures, kyphosis and spinal cord compression. Vertebra plana may occur owing to compression and fracture of vertebral bodies. In addition, trabecular destruction and thinning of both the outer and inner tables of the calvaria may be present. Other abnormalities include fractures of the ribs, tubular bones of the appendicular skeleton and femoral neck, with coxa vara deformity.

Bone modelling abnormalities are typical, especially an Erlenmeyer flask deformity (Fig.1). Similarly, unusual steplike depressions in the superior and inferior margins of the vertebral bodies (termed an H vertebra) have been described in Gaucher's disease.

Osteonecrosis is well recognized in Gaucher's disease and may involve epiphyses and diaphyses of the long bones, leading to alternating radiolucent areas and sclerosis in association with periostitis and a bone-within-bone appearance.

Radionuclide bone imaging of the bone and bone marrow has allowed determination of the extent and severity of skeletal involvement in patients with Gaucher's disease. Bone crises occur in this disease, and at the onset of a crisis, the bone scan typically shows decreased uptake of the radionuclide at the involved site. After resolution of the crisis, increased uptake surrounding a region of decreased uptake may be evident after several weeks

Computed tomography CT is also useful in assessing the extent of marrow involvement in Gaucher's disease. Quantitative CT allows monitoring of the levels of marrow fat and can help assess the patient's response to therapy.

MR imaging shows regions of abnormal bone marrow as areas of decreased signal intensity on T1-weighted and T2-weighted spin-echo MR images.

DR/RB