MALT Lymphoma
Overview Definition MALT lymphoma is a clinically indolent non-Hodgkin’s lymphoma postulated to arise from postgerminal center memory B cells with the capacity to differentiate into marginal zone cells and plasma cells. Epidemiology Relatively uncommon subtype of non-Hodgkin’s lymphoma: 5%–10% of all non-Hodgkin’s lymphomas Approximately half of non-Hodgkin’s lymphomas in stomach, ocular adnexa, and lung Incidence […]
Multiple Endocrine Neoplasia
Overview Definition Multiple endocrine neoplasia (MEN) syndromes are genetic disorders characterized by the presence of ≥ 2 endocrine tumors. Types General descriptions Table: Multiple endocrine neoplasia (MEN) syndromes MEN1 MEN2A and MEN2B MEN4 Pattern Autosomal dominant Autosomal dominant Autosomal dominant Genetic mutation MEN1 gene on chromosome 11 (11q13) RET proto-oncogene on chromosome 10 (10q11.2) CDKN1B […]
Hemolytic Disease of the Fetus and Newborn
Overview Definition Hemolytic disease of the fetus and newborn (HDFN) is hemolytic anemia of the fetus or newborn of varying degrees of severity due to maternal IgG antibodies against fetal RBC surface antigens. Epidemiology Etiology Pathophysiology During pregnancy, fetal RBCs move across the placenta into the maternal circulation: ABO incompatibility: Rhesus incompatibility: Clinical Presentation Fetus […]
Atherosclerosis
Overview Definition Atherosclerosis is a common form of arterial disease in which lipid deposition forms a plaque in the blood vessel walls. Epidemiology Leading cause of cardiovascular disease and death worldwide More common in men Most common locations: abdominal aorta, coronary arteries, popliteal arteries, cerebral and carotid arteries Often starts in childhood as fatty streaks […]
Lactose Intolerance
Epidemiology Etiology Primary LD Secondary LD Less common types of LD Pathophysiology General consideration Lactase Effects of undigested lactose Clinical Presentation Children and adolescents Adults Diagnosis Consider a diagnosis of LI if typical symptoms occur within a few hours after ingestion of a lactose-containing meal and resolve after 5–7 days. Testing for LD Note: Tests […]
Hyperaldosteronism
Overview Definition Hyperaldosteronism is defined as an increased secretion of aldosterone from the zona glomerulosa of the adrenal cortex. Primary hyperaldosteronism: autonomous (renin-independent) secretion of aldosterone Secondary hyperaldosteronism: physiological oversecretion of aldosterone that occurs in response to overstimulation of the RAAS, triggered by decreases in renal blood flow. Epidemiology Prevalence of primary hyperaldosteronism: 0.5%‒2% in […]
Adrenal Insufficiency and Addison Disease
Overview Definition Adrenal insufficiency (AI) is the deficiency in adrenal production of glucocorticoids, adrenal androgens, and mineralocorticoids. Forms of adrenal insufficiency Epidemiology Etiology Etiology of primary adrenal insufficiency Etiology of secondary and tertiary adrenal insufficiency Consequence of dysfunction of the hypothalamus and pituitary gland: Pathophysiology Hormonal regulation Adrenal insufficiency Primary AI: Secondary AI: Tertiary AI: […]
Peritoneal Dialysis and Hemodialysis
Overview Definition Dialysis is a form of renal replacement therapy (RRT) that is used to perform the blood-filtering role of the kidneys when the kidneys are not functioning. The conditions generally include: AKI CKD Types: Hemodialysis Peritoneal dialysis Indications for dialysis in acute kidney injury Acute kidney injury is sometimes so severe that dialysis is […]
Cardiomyopathy: Overview and Types
Overview Definition Cardiomyopathies are diseases that affect the structure and function of the heart muscle (myocardium) in the absence of secondary causes (e.g., coronary artery disease, hypertension, valvular disease, and congenital heart disease). Epidemiology Etiology Causes vary: Approximately ⅓ of cases have a genetic cause. Classification By morphology: By etiology: Pathophysiology Diagnosis Diagnostic approach varies […]
Atopic Dermatitis (Eczema)
Overview Definition Atopic dermatitis (also known as eczema) is a disorder of altered skin barrier integrity and immune dysregulation that presents as a chronic relapsing inflammatory skin disease. Epidemiology Prevalence: School-aged children: approximately 17% Adults: 2%–10% Atopic triad (present in 30%–50% of patients): Atopic dermatitis Allergic rhinitis Asthma 30% of patients develop asthma. Vast majority […]