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NON-NEOPLASTIC DISEASES OF HEMATOPOETIC ORGANS Pathology. Jan Żeromski 200 10 /20 11. PATHOLOGY OF THYMUS. Developmental defects – a plasia (Di George anomal y) , Nezelof syndrome
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NON-NEOPLASTIC DISEASES OF HEMATOPOETIC ORGANS Pathology Jan Żeromski 20010/2011
PATHOLOGYOF THYMUS • Developmental defects – aplasia (Di George anomaly), Nezelofsyndrome • Follicular hyperplasia with germinal center formation (myasthenia – in 70% of cases,SLE, Graves disease) • Thymic tumors: • Thymomas - tumors of thymic epithelial cells - Benign-mostly of medullaryepithelialcells - Malignant • Type I - cytologically benign but biologically aggressive (mainly of corticalepthelialcells) • Type II - „thymic carcinoma”- 5% of thymomas • Lymphomas ( of T cell)Hodgkin’ disease • Others ( carcinoids, teratomas etc.)
PATHOLOGY OF LYMPH NODES (LN) • Lack or hypoplasia of LN cortex - in immunodefic. • Atrophy - in old age, after irradiation, chemotherapy • Inflammations - acute, chronic, non-specific, specific • Enlargement due to storage of various compounds • Tumors: • Primary - lymphomas • Secondary - carcinomas (metastases)
CHRONIC NON SPECIFIC LYMPHADENITIS • Follicular hyperplasia: caused by infection with microbes activating B cells. • Paracotical lymphoid hyperplasia: due to infection with microbes activating T cells. • Sinus histiocytosis: accumulation of histiocytes in lymphatic sinusoids. Occurs in LNs draining cancers (of breast and/or stomach).
CHRONIC „SPECIFIC’ LYMPHADENITIDES • Toxoplasmosis:Small epithelioid cell granulomas, both T and B cell are involved. • Cat scratch disease:(e.: small Gram neg. bacteria). Enlargement and suppuration of LN after skin incident such as cat scratch. • Lymphogranuloma venereum:(e.: Chlamydia)Enlargement of LN, granuloma formation - suppuration, liquefaction. • Mesenteric lymphonodulitis:(e.: Yersinia pseudotuberculosa) - Granulomas with tendency to necrosis of mesenteric LNs.
CHRONIC „SPECIFIC” LYMPHADENITIS 2 • Tuberculosis: (e.: tubercle bacilli)Necrotic granulomas • Tularemia: (e.: Francisellatularensis)Focal necrotic lesions in LN and other organs surrounded by monocytes, fibroblasts, lymphocytes as in tbc. • Sarcoidosis:Granulomas formed by mononuclear phagocytes surrounded by a rim of T-helper cells and sometimes B lymphocytes. They are due to cytokine release by Th. • Infectious mononucleosis: (e.EBV infection)Activation of T area, immunoblast infiltrates, dispersed light reticulum cells, sinuses widened with immunoblasts and plasma cells.
Millary tuberculosis of the spleen Typical epithelioid cell tubercles with Langhans` giant cells. HE, 100x
Tularemic lymphadenitis; margin of necrotic area No caseation, though there are scattered areas of necrosis. Note epithelioid cell zone with several Langhans` giant cells.
Lymphadenitis due to tularemia (Pasteurella tularensis) Center: necrotic area surrounded by wide zone of epithelioid cells with a few Langhans` giant cells. At the upper boundary of the central wedgeshaped area of necrosis there is some nuclear debris. Diagnosis serologically confirmed. HE, 65x
Sarcoidosis of hilar lymph nodes Epithelioid cell nodules without caseation; much fibrosis and abundant giant cells. Center: an “asteroid body”. HE, 100x
OTHERLYMPHADENOPATHIES • Post vaccinal and viral lymphadenitis LN draining the site of vaccination ( polio, tetanus, pertussis, diphteria) and viral infections, (CMV, influenza), Hist. - diffuse hyperplasia and an increase of immunoblasts. • Anticonvulsant drug lymphadenopathy (dilantin L.)may happen after 1 week to many months after therapy Sympt. - skin rash, fever, hepatosplenomegaly, painful joints.
OTHER LYMHADENOPATHIES 2 • Dermatopathic L. (lipomelanoticreticulosis)associated with chronic dermatosis esp. exfoliative type Hist. - widened pale-stained T-zone areas with foaming vacuolated macrophages with fat and/or melanin droplets. • Lymphadenitis following lymphangiographydue to accumulation of fat globules in LN sinuses • Whipple disease(e.TropherymawhippelliGram+ bact.)accumulation of pale-staining, PAS+ macrophagesloadedwithbacteria in small intestinal mucosa and sinuses of draining LN clin.: malabsorption syndrome, polyarthritis, lymphadenopathy,hyperpigmentation, psychiatricdisorders
OTHER LYMPHADENOPATIES - 3 HIV-relatedlymphadenopathy (verylargelymphoidfollicleswithgiant germinal centers, laterfragmentation and atrophy) Lymphadenopathyinrheumatoidarthritis (enlargement of lymphoidfollicles, lowproliferativeactivity of germinal centers, accumulation of plasmacellsbetweenfollicles, infiltration of neutrophilsinsinuses Lymphadenopathyininfectiousmononucleosis(in paracorticalareaproliferation of immunoblasts – mostly B cells, with high mitoticactivity
VIRUS-ASSOCIATED HEMOPHAGOCYTIC SYNDROME(VAHS) • Etiology: rarecomplication of viralinfections (EBV, CMV,adenoviruses, B19 parvovirus and other) • Incidence: most often in renal transplant and/or immunosuppressed patients • Clin.:fever, pulmonary infiltrates, hepatospleno-megaly, lymphadenopathy, cytopenia • Hist.:LN enlarged, small lymphoid follicles without germinal centers, with abundant nuclear debris, free or in cytoplasm of proliferating histiocytes. • Prognosis: uncertain, potentially reversible
CASTLEMAN DISEASE Two major grosstypes : single localized– large tumor inmediastinum, non-specificsymptoms: fever, anemia, hypo-proteinemia, polyclonalhipergammapathy;goodprognosis Multifocal– general lymphadenopathy,highfever, weightloss, skin changes, hemolysis, poli- ormono-hypergammapathy, possibleprogress to lymphoma; poorprognosis Probableetiology: infectionwithherpesvirus HHV-8 Histology – twotypes: vascular hyaline- atrophy of germinal centersinlymphoidfollicles, numerousvenulessurrounded by hyalinemasses(angiofollicular lymphnode hyperplasia) (predominantin single localisedtype) plasma cellular– interfollicularspacesfilledwithplasmacells (predominantinmultifocaltype)
SPLEEN – MAJOR FUNCTIONS • Filtration of unwanted elements from blood – aged and damaged cells, but also bacteria, cell debris,abnormal metabolic molecules - phagocytic functions • Major secondary organ in the immune system- antibody production, especially of IgM class • A source of lymphoreticular and hematopoetic cells • A reserve pool and storage site of blood cells
CAUSES OF SPLENOMEGALY • Infections • Congestive states • Lymphohematologic disorders • Parasitic infestations • Connective tissue diseases • Storage diseases • Varia (amyloidosis, cysts, neoplasms etc.)
Splenomegaly associated with acute infection (“septic spleen”) Septicemia arising from liver abscesses due to echinococcosis.Spleen weight 610g.
Splenomegaly associated with acute infection Hyperplasia of reticulum cells in red pulp. Note presence of large pulp cells separated from their normal connection. Leucocyte infiltration, erythrophagocytosis. HE, 520x
Chronic splenomegaly in response to infection Note active proliferation of reticulum cells, deployment of littoral cells, erythrophagocytosis. HE, 520x
Hypersplenism – clinical features • Splenomegaly –dragging sensations in the abdomen (left upper quadrant) • Discomfort after eating • Anemia, leukopenia • Thrombocytopenia • Hyperplasia of bone marrow precursors
Banti Syndrome – Non-cirrhotic or Idiopathic Portal Hypertension Etiology • After subclinical occlusion of the portal vein Symptoms • Splenomegaly, hypersplenism, anemia Hist. • Splenic red pulp replaced by fibrosis • deposition of collagen in basement membranes of sinusoids impairs blood flow leading to excessive destruction of blood cells. • Focal hemorrhages become organised with deposits of hemosiderin and calcium (Gamna-Gandi bodies). Treatment • surgical shunting procedures
LEUKOCYTOSIS • Granulocytosis (inflammations, tissue necroses) • Eosinophilia (allergy, parasitic infect., some skin diseases) • Lymphocytosis(viral infections, severe chronic infections) • Monocytosis (severe chronic bacterial/fungal inf.) • Mastocytosis(increased numbers of mast cells in skin and sometimes in other organs) • Leukemoid reaction (huge numbers of immature cells in blood
Reduced production Suppression of myeloid stem cells Neoplastic occupation of bone marrow Suppression of granulocyte precursors Vit. B12 or folate deficiency Accelerated removal Hypersplenism Inreased utilization-in infections Felty’s syndrome Exposure to drugs Proliferation of CD8+ LGL in bone marrow LEUKOPENIA-USUALLY GRANULOCYTOPENIA (BELOW 1000/c.mm)
Features Of Mononuclear Phagocyte System – MPS (Reticulo - Endothelial Sys.) Compounds: Monocytes, macrophages, reticulum cells, histiocytes, endothelia, dendritic cells. Function: • endocytosis (phagocytosis, pinocytosis) • storage and clearance • secretory activity • role in immune reactions • role in inflammation and infection
PROLIFERATIVE DISORDERS OF MPS • Localized (reactive or neoplastic) • Multicentric • reactive (Tbc, sarcoidosis) • neoplastic (?) • Systemic • reactive (storage diseases, VAHS) • neoplastic (malignant histiocytosis)
LANGERHANS’ CELL HISTIOCYTOSIS (HISTIOCYTOSIS X) (1) Unifocal: eosinophilic granuloma • Expanding erosiveaccumulation of Langerhans’ cells (dendritic cells) admixed with eosinophils, plasma cells, lymphocytes within medullary cavities of bones. • Any bone may be involved, but commonly ribs, calvarium, femur but also teeth.
LANGERHANS’ CELL (LC) HISTIOCYTOSIS (HISTIOCYTOSIS X) (2) Multifocal:Hand – Schuller - Christian dis. • Proliferation of mature Langerhans’ cells with abundant intracytoplasmic lipids (cholesterol, its esters, neutral fats) • Aberrant expression of chemokine receptors – CCR6 and CCR7 on LC – migration to tissues • Clin.: triad-bone lesions, exophtalmos, diabetes insipidus (due tp involvement posterior stalk of the hypothalamus) also - fever, skin eruptions, hepatospleno-megaly • Young children are affected,Prognosis fairly good
LANGERHANS’CELL HISTIOCYTOSIS (HISTIOCYTOSIS X) (3) Systemic: acute disseminated (Letterer - Siwe disease • progressive proliferation of L. Cells leading to destruction of hematopoesis, recurrent infections and often to death, • Clin. - cutanous lesions, later involvement of internal organs – hepatosplenomegaly, lymphadenopathy, • Children before two years of age are affected. • Prognosis – poor
GAUCHER DISEASE • Pathogenesis: Proliferation of histiocytes filled up with glucocerebroside - lack of glucocerebrosidase, an enzyme needed to hydrolize glycolipids from senescent blood cells • Gen.: Mutation on chromosome 1 (q21-q31) • Symptoms: Splenohepatomegaly (giant spleen up to 10 kg), erosion of bones, anemia, leucopenia, various neuropathies • Hist.: Infiltration of organs with Gaucher cells rich in glucocerebrosides stored in lysosomes • Three types - adults (99%), infantile, juvenile.
NIEMANN-PICK DISEASE • Pathogenesis: • Accumulation of sphingomyelin in histiocytes (derived from cell membranes, subcellular organelles, myelin sheaths) • Lack of sphingomyelinase in two forms of N-P disease • Hist.: Foam cells in spleen, bone marrow, liver, lymph nodes • Clin.: Hepatosplenomegaly, cachexia, mental retardation • Two types: A - in infants (80%) and B - without involvement of CNS