Chronic inflammation
Chronic inflammation this is an inflammation of slow progress and so of longer duration lasting for several months to years and is typified by influx of lymphocyte, macrophage and plasma cells with associated tissue destruction and repair process (new vessels formation(angiogenesis) and fibrosis
Chronic inflammation may be subdivided as follow
Non specific chronic inflammation arise following non-resolution of acute inflammation such as delay evolution of an abscess and recurrent acute cholecystitis, recurrent acute pyelonephritis. Specific (primary) chronic inflammation arise de nova (from the beginning) in response to certain type of injurious agents such as
Certain microorganisms cause chronic rather than acute inflammation e.g. leprosy, T.B., syphilis
Autoimmune diseases e.g. rheumatoid arthritis
Chemical injury include response to asbestos or silica particles
Viral infections need lymphocyte from the beggining
Granulomatous inflammation this is a subset of specific chronic inflammation characterized by the presence of granulomas e.g. T.B., leprosy ,syphilis, sarcoidosis and chrons disease
Examples of chronic inflammation
Chronic pyelonephritis
Its define as interstitial inflammation and scarring of the renal parenchyma
Usually its occur after recurrent acute pyelonephritis
Its an important cause of chronic renal failure
Clinical features
The patient usually presented late in the course of disease, so it may be present with hypertension or polyuria, nocturia, bacteriuria, proteinuria or may presented with chronic renal failure
Grossly
The kidneys became small in size and asymmetrically contracted
Microscopically
interstitial fibrosis
chronic inflammatory cell infiltration in the interstitial space
dilation or contraction of tubules with atrophy of lining epithelium
replacement of glomerular tufts by avascular, acellular hyaline material
Chronic sialadenitis
It is chronic inflammation of the major salivary glands(submandibular gland is most frequently involved) , most often occurs secondary to ductal obstruction resulting from stone formation (sialolithiasis), but it may be arise after retrograde entry of oral cavity bacteria under condition of sever systemic dehydration such as postoperative state
Microscopically
dilation of duct branch with periductal fibrosis
lymphocyte infiltration with formation of lymphoid follicle
atrophy of secretory acini
interstitial fibrosis
Tuberculosis T.B
It is a communicable chronic granulomatous disease caused by mycobacterium tuberculosis. Its usually involve the lungs but may affect any organ or tissue in the body. Typically the center of tubercular granuloma undergo caseous necrosis
Risk factors for developing TB
Poverty, crowding , malnutrition , alcoholism
Grossly
Granulomatous disease grossly appears as irregularly sized rounded nodules that are firm and tan. Larger nodules may have central necrosis known as caseation-
The caseous material is soft, friable, whitish, cheesy material
Microscopically
The TB characterized by granuloma formation which is 0.5-2mm in diameter and its formed by collection epithelioid cells(transformed macrophage) usually surrounded by a rim of lymphocytes and some time fibroblast
The caseous necrosis occupy the center of granuloma, it has distinctive amorphous granular pinkish debris
Langhans giant cell is seen with in the granuloma, this cell is formed by fusion of several epithelioid cells , so it appear as large cell with one cytoplasm and several nuclei which arranged at periphery as horseshow
Clinical feature
Anorexia, weight loss, lassitude sleep sweating, evening pyrexia