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| Myelofibrosis | ||
| Etiology •Unknown. | ||
| Pathogenesis •The mechanism of myelofibrosis is unknown, but is believed to be due to the abnormal proliferation of fibroblasts in response to cytokines (primarily TGF-beta and PDGF) from megakaryocytes., | ||
| Epidemiology •The disease usually affects individuals late in life (sixth through eighth decade). •Both sexes are equally affected. | ||
| General Gross Description •The bone reveals a firm, homogeneous, tan to white appearance instead of the normal appearance of red marrow, flecked with bone spicules. •Examples: | ||
| General Microscopic Description •Microscopically, the entire marrow space is replaced with mature collagen and fibroblasts. •Megakaryocytes may be seen even in late stages. •Examples: | ||
| Clinical Correlation •Clinically, the loss of marrow function in the bone stimulates myelopoiesis in extramedullary sites, such as spleen and liver. •For this reason, the disease is also known as agnogenic myeloid metaplasia. •Symptoms may be due to the enlargement of the spleen (a dragging sensation in the left side); or due to the reduction in red and white cell function. •Sometimes preceded by myelogenous leukemia, or polycythemia vera; often, however, the cause is unknown. •The prognosis is not good, with relatively few individuals surviving five years. | ||
| References • Cotran RS, Kumar V, Robbins SL: Robbins Pathologic Basis of Disease. 5th edition. Philadelphia, W.B. Saunders, 1994, pp.660. Please be patient during transfer. Medline will open in a new window. To return, close the Medline Window Myelofibrosis
| Synopsis by: T.V. Rajan M.D. PhD. (T10510M49000)[78]
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