Extramedullary hemopoiesis.

Various chronic hematologic disorders that lead to ineffective hemopoiesis or inadequate bone marrow function (ie, chronic hemolytic anemias, thalassemia, sickle cell anemia, myelofibrosis of many causes, lymphoma, and leukemia) can potentially precipitate extramarrow new blood element creation. Extramarrow soft tissue that produces blood elements is called extramedullary hemopoietic tissue and the process extramedullary hemopoiesis (EMH). Sites commonly involved by EMH include the liver, spleen, lymph nodes, and most commonly, paravertebral regions, although other sites can sometimes be involved. Physicians rarely consider EMH in their differential diagnosis even in cases where it is warranted (diseases of ineffective erythropoiesis). This is likely because of the rarity of the condition and because imaging findings are nonspecific. We present here a systematic review of the imaging findings in EMH.

Amyloidosis: review and imaging findings.

Amyloidosis is a collection of pathophysiologically related disease entities caused by the extracellular deposition of abnormal fibrillar proteins called amyloid. The accumulation of amyloid may be systemic, involving many organs, or localized manifesting as infiltration of individual organs, or in the form of a focal, tumorlike lesion. Amyloidosis may develop in the setting of underlying conditions, usually chronic inflammatory diseases, in which case it is termed secondary, or it may involve no underlying disease and thus be primary or idiopathic. Amyloid infiltration leads to pathology through the disruption of normal tissue structure and function or through cytotoxic effects of intermediate forms of protein aggregates. Clinical manifestations of the disease vary and are nonspecific, increasing the need of imaging during the investigation of the disease. Imaging findings are diverse and not pathognomonic; however, combined with the patient's clinical history they can raise the suspicion of amyloidosis and direct toward its confirmation by biopsy. Radiologists should be familiar with the appearance of amyloidosis in various modalities to aid the early identification of the disease and direct toward prompt treatment planning. Such knowledge would provide the radiologist with an opportunity to contribute to patient care and aid reducing the high morbidity and mortality of the disease.

Serum total homocysteine, folate, 5,10-methylenetetrahydrofolate reductase (MTHFR) 677C-->T genotype and subclinical atherosclerosis.

OBJECTIVE: To determine the relationship of serum total homocysteine (tHcy), serum folate and 5,10-methylenetetrahydrofolate reductase (MTHFR) 677C-->T genotype with ultrasonic arterial wall measurements associated with subclinical atherosclerosis. STUDY DESIGN: Cross-sectional analysis of 767 participants in an ongoing prospective study. Intima-media thickness (IMT) of the common carotid (IMTcc), IMT of the internal carotid including plaque when present (IMT(max)) and the sum of the thickest plaques present in both carotid and both common femoral bifurcations (total plaque thickness (TPT)) were measured using ultrasound. RESULTS: People in the upper homocysteine quartile were more likely to have clinical cardiovascular disease (CVD) than those in the lowest three quartiles. They were also more likely to have plaques. The MTHFR 677C-->T genotype was not associated with any of the measures of subclinical atherosclerosis in either men or women but was the most important determinant of total homocysteine levels in men under 60 years of age. CONCLUSIONS: Increased homocysteine levels but not MTHFR 677C-->T genotype, are associated with subclinical atherosclerosis and the presence of plaques. Our results indicate that measurements of blood levels of homocysteine and folate in people at intermediate risk for atherosclerotic CVD before symptoms occur, might improve risk stratification and facilitate the decision to provide folate/B vitamin intervention in primary prevention.