digest on pathomorhology

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differs from normal ganglia as it has the signs of atypism (polynuclear cells, tigrolysis, and nuclear decentralization. Schwann‟s glia is represented by satellite cells. The tumor does not produce metastases.

Malignant ganglioncuroblastoma is a combination of neuroblastoma and ganglioneuroma. The tumor develops intrauterinely or during the first years of life. It may be localized in any region of vegetative nervous system, small intramural ganglia of the inner organs, medullar layer of adrenal glands and sympathetic trunks. Sometimes it matures and turns into ganglioneuroma.

Nonchromophilic paraganglioma is a benign variant. It resembles the tumors of APUD system (APUDomas). It can produce ACTH and serotonin. The tumor is localized in the middle ear, retroperitoneally. It may be large; its histological structure is alveolar and trabecular with large number of sinusoid vessels.

Malignant paraganglioma. This is characterized by cellular polymorphism, infiltrating growth, lymphogenic metastases. Thus, the tumors of peripheral ganglias correspond to different stages of their embryonic structure. Lest mature is neuroblastoma, the most manure is ganglioneuroma. Ganglioneuroblastoma occupies an intermediate place.

Tumors of peripheral nervous system

Tumors of peripheral nervous system originate from the nerve membranes. Neurilemma

(Schwannoma), neurofibroma, neurofibromatosis (Recklinghausen‟s disease) are benign ones.

Schwannoma is formed of spinder-like cells with rod-shaped nuclei. The cells and fibers form rhythmical structures. Neurofibroma is a tumor connected with the nerve membrane. It consists of connective tissue with nervous cells, bodies and fibers.

Neurofibromatosis is a systemic disorder characterized by development of multiplies neurofibromas associated with different development defects. This may be peripheral and central.

Malignant neurilemma is neurogenic sarcoma. Pilymorphocellular atypism, polynuclear symplasts, garden-like structure is characteristic.

TUMORS OF MELANIN-PRODUCING TISSUE

Melanin-producing cells (melaninocytes) are of neurogeneous origin. They may become the origin of tumor-like formations (nevi) and melanomas.

Nevi are benign tumors of skin consisting of melanocytes of epidermis and derma. Neurogeneous origin of melanocytes is generally recognized. Nevi are defects of development of neuroectodermal pigment elements.

They look like brown spots of different size, and may be either flat or elevated over the surface or be wart-like. Sometimes their size is enormous (giant pigmented nevus).

According to the WHO classification (1974), there are the following types of nevi:

1.Junctional nevus.

2.Compound nevus.

3.Intradermal.

4.Epithelioid nevus (intracellular).

5.Balloon-cell nevus.

6.Halo nevus.

7.Giant pigmented nevus.

8.Involution nevus (fibrous papule of the nose).

9.Blue nevus.

10.Cellular blue nevus.

Junctional nevus. Nests of nevus cells are found on the border of epidermis and dermis. The nests are round or oval. Their-cytoplasm is homogeneous, slightly granular. The nevus cells are localized in the area of reticular layer apices.

Compound nevus. Together with the nevus cells located on the border of dermis and epidermis, there are nests of nevus cells in derma itself.

Intradermal nevus. Nevus cells are located only in derma. Some of them can be found on the border between derma and epidermis. They resemble nests. The nevus cells look like compact mass. The cells in mature nevi may be polynuclear. Macroscopically they have papillomatous appearance and may contain hairs.

Epithelioid nevus or juvenile melanoma can often appear on the face, especially in children. It looks like flat or ball-like node. The surface of the skin is smooth, sometimes-

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papillomatous changes are observed. Microscopically it looks like compound nevus with borderline changes. Sometimes marked acanthosis is present. The amount of melanin is small; it may also be absent. The cells have light basophilic cytoplasm and hyperchronic nuclei. Epithelioid cells with large foamy light cytoplasm may be present. Mitoses are not numerous. Unior polynuclear cells resemble Teuton’s cells. There are a lot of vessels.

Blue nevus. Macroscopically this looks like bluish or bluish-brown or bluish-gray sport, its shape is round or oval, it does not elevate over the surface of the skin. Microscopic examination reveals stretched melanocytes.

Melanoma

Melanoma is one of the most malignant tumors, it spreads through the lymphatic and hematogenic routs. 70% of melanomas develop on the skin of the face, body and extremities.

Depending upon the clinical course and prognosis, cutaneus malignant melanomas are of the following 4 types:

1.Lentigo maligna melanoma. This often develops from a pre-existing lentigo. It is essentially a malignant melanoma in situ.

2.Superficially disseminated melanoma (invasive melanoma). This is a slightly elevated lesion with variegated color and ulcerated surface. It often develops from a superficial spreading melanoma in situ. Melanomas may not contain pigments. In the tumor, there are a lot of mitoses, hemorrhages and necroses. The tumors are localized on the skin, pigment membrane of the eye, meninges, and medullar layer of adrenal glands, in rare cases mucous membranes.

3.Acral lentigenous melanoma. This occurs more commonly on the soles, palms and mucosal surfaces. The tumor often undergoes ulceration an early metastases.

4.Nodular melanoma. This often appears as an elevated and deeply pigmented nodule that grows rapidly and undergoes ulceration. This variant carries the worst prognosis.

Histologically, melanoma cells are larger than nevus cells with irregular nuclei and prominent eosinophilic nucleoli; they grow as loose nests lacking the typical features of maturation. They may be epithelioid or spindle-shaped. Mitotic figures are often present and multinucleate giant cells may occur. These tumor cells may be arranged in various patterns such as solid masses, sheets, island, alveoli etc. Melanin pigment may be present or absent without any prognostic influence. Some amount of inflammatory infiltrate is present in the invasive melanomas. Although morphologic variants of the radial growth phase have been described, the nature and extent of the vertical growth phase determines the biologic behavior and prognosis.

Metastatic spread of melanoma is very common and takes place via lymphatics to the regional lymph nodes and through blood to distant sites like lungs, liver, brain, spinal cord, and adrenals.

LEUKEMIAS

Leukemias are malignant neoplasms of the hematopoietic stem cells characterized by diffuse replacement of the bone marrow by neoplastic cells.

General characteristic

In the major, the leukemic cells spill over into the blood, where they may be seen in large number. These cells may also infiltrate the liver, spleen, lymph nodes and other tissues throughout the body.

Traditionally, leukemias are classified on the basis of the cell type involved and the state of maturity of the leukemic cells. Thus, acute leukemias are characterized by the presence of very immature cells (called blasts) and by a rapidly fatal course in untreated patients.

On the other hand, chronic leukemias are associated, at least initially, with welldifferentiated (mature) leukocytes and with a relatively indolent course.

The type of acute and chronic leukemia is established on the basis of cytochemical peculiarities of tumor cells.

Acute leukemias, despite differences in their cell of origin, share important morphologic and clinical features. They are associated with replacement of normal marrow elements by a sea of proliferating “blast cells” that do not seem to undergo normal maturation.

Classification of the leukemias

I.Acute leukemias:

1.Undifferentiated.

2.Myeloblast.

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3.Lymphoblast.

4.Plasmoblast.

5.Monoblast.

6.Erythromyeloblast.

7.Megacaryoblast.

II.Chronic leukemias:

1.Of myelocyte origin:

Chronic myeloid.

Chronic erythromyelosis.

Erythremia.

True polycytemia (Vaquez-Osler syndrome).

2.Of lymphocyte origin:

Chronic lympholeukemia.

Skin lymphomatosis (Sezary’s disease).

3.Paraproteinemic leukoses:

Myeloma.

Primary macroglobulinemia (Valdenstrem’s disease).

Heavy chain disease (Franklin’s disease).

4.Of monocyte origin:

Chronic monocyte leukemia.

Histiocytosis.

Classification based on the number of leukemic cells in 1 mcl of blood:

1.Leukemic (tens and hundreds thousand leukemia cells per 1 mcl).

2.Subleukemic (not more that 15.00%-25.000 per 1 mcl).

3.Leukopenic (leukocyte count is reduced but leukemia cells can be found).

4.Aleukemic (leukemic cells in the blood are almost absent).

Morphology of all leukemias

There are two aspects to the morphologic features of leukemia:

1.The specific cytologic details of the leukemic cells seen in periferal blood smears and bone marrow aspirates.

2.The tissue changes produced by infiltrations of leukemic cells.

The tissue alterations produced by various leukemias are often similar and may be separated into primary changes, attributed directly to the abnormal overgrowth or accumulation of white cells; and secondary changes, caused both by the destructive effects of masses of these cells and by their relative infectiveness in protecting against infection.

Although leukemic cells may infiltrate any tissue or organ of the body.

Leukemic infiltration of hemopoietic organs (bone marrow, spleen, lymph nodes) at first, then of the other organs (mucous membranes, myocardium, kidneys, brain, vessels, etc.).

The most striking changes are seen in the bone marrow, spleen, and liver: massive splenomegaly, lymhp node enlargement, enlargement of the liver.

Pyoid bone marrow due to proliferation of the tumor cells (mature or immature, respectively) in the bone marrow with displacement of the red sprout. Macroscopically, bone marrow is grayish-whitish.

Necrotic tonsillitis, gingivitis develops due to leukemia infiltration of the oral mucosa and tonsils against a background of immunogenesis inhibition. Besides, infiltrates in the gingiva are particularly characteristic of monocytic leukemia.

The secondary changes of all forms of leukemia are:

a)Anemia and thrombocytopenia, especially in acute leukemia.

b)The bleeding diathesis.

c)Petechial and ecchymoses.

d)Hemorrhages into the serosal linings of the body cavities, mucosal hemorrhages etc.

e)Disseminating intravascular coagulation may also lead to widespread bleeding.

f)And, finally, infections and sepsis are a prominent feature, especially in acute leukemias.

Foci of extramedullary hemopoiesis develop in the liver, spleen, kidneys, and lymph nodes. There is compensatory adaptation reaction directed to restoration of the red sprout.

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Distinctive features of acute and chronic leukemia are:

1)Bone marrow and blood picture (in acute leukemia blasts are observed, in chronic mature cells are found).

2)Leukemic failure (hiatus leukemicus) characterizes acute leukemia. It is sharp increase of blast count and single mature elements while transitional forms are absent.

3)Sharp enlargement of the spleen, liver, kidneys and lymph nodes characterizes chronic leukemia while in chronic one it is less marked. The spleen can weigh 6 - 8 kg, the liver 5 - 6 kg.

Complications and causes of death:

1)Hemorrhage to vital organs (brain).

2)Ulcerative necrotic and septic complications (sepsis).

Chronic myeloid leukemia (CML)

Chronic myeloid (myelogenous, granulocytic) leukemia comprises about 20% of all leukemias and its peak incidence is seen in 3rd and 4th decades of life. A distinctive variant of CML seen in children less than 3 years of age is called juvenile CML.

Clinical Features

At research of chromosome clearly recognize Philadelphia chromosome, associated with poor prognosis.

Leukemic infiltration contains myelocytes and metamyelocytes.

Pyoid bone marrow.

Features of anemia such as weakness, pallor, dyspnoe and tachycardia.

Symptoms due to hypermetabolism such as weight loss, lassitude, anorexia, night sweats.

Splenomegaly and hepatomegaly is almost always present and is frequently massive.

Bleeding tendencies in blast crises.

Less commonly, features such as gout, visual disturbance, neurologic manifestations and priapism are present.

Juvenile CML is more often associated with lymph node enlargement than splenomegaly.

Chronic lymphocytic leukemia (CLL)

Chronic lymphocytic leukemia constitutes about 25% of all leukemias and is predominantly a disease of the elderly (over 50 years of age) with a male preponderance (male-female ratio 2:1).

Clinical Features:

Features of autoimmune hemolytic anemia such as weakness, fatigue and dyspnoe.

Enlargement of superficial lymph nodes.

Splenomegaly and hepatomegaly are usual.

Hemorrhagic manifestations are found in CLL with thrombocytopenia.

Infections, particularly of respiratory tract, are common.

Paraproteinemic leukemias

The most important of this group is myeloma.

The disease is characterized by growth of tumor lymphoplasmocytic cells (myelomic cells) in the bone marrow and other organs.

Bone marrow myelomatosis causes bone destruction. Sinusal resorption of the bone results in osteolysis and osteoporosis. The bones become fragile.

Hypercalcemia develops due to their destruction; it may be followed by development of calcific metastases.

Myelomic-cell infiltration develops in the inner organs: spleen, lymphatic nodes, liver, kidneys, lungs, etc.

A number of changes are associated with secretion of paraprotein by the tumor cells. These changes are amyloidosis, paraproteinemic nephrosis or myelomic nephropathy resulting in shrunken kidney.

Depending on the character of myelomic cells, myelomas are divided into:

1.Plasmocyte.

2.Plasmoblast.

3.Polymorphocellular.

4.Small-cell.

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Morphologically, depending on the character of myelomic infiltrations the following forms are distinguished:

1.Diffuse.

2.Diffuse nodular.

3.Multiple nodular.

Causes of death are uremia, sepsis, necrotic changes, and amyloidosis.

LYMPHOMAS

Lymphomas are malignant neoplasms characterized by the proliferation of cells native to the lymphoid tissues that is lymphocytes, histiocytes and their precursors and derivatives.

Like other neoplasms, all lymphomas are of monoclonal origin.

Two distinct clinicopathologic groups are distinguished:

I. Hodgkin‟s lymphoma or Hodgkin‟s disease (HD).

II. Non-Hodgkin „s lymphomas (NHL).

Non – Hodgkin’s lymphomas

The usual presentation of Non-Hodgkin‟s lymphomas (NHL) is a localized or generalized lymphadenopathy.

However, in about one-third of cases it may be primary in other sites where lymphoid tissue is found, for example, in the oropharyngeal region, bone marrow, gut and skin.

All forms of lymphoma have the potential to spread from their origin in a single node or chain of nodes to the other nodes, and eventually to disseminate to the spleen, liver and the bone marrow.

There are some important principles of classification of NHL.

As all tumors of the immune system, NHLs may originate in T-cells, B-cells, or histiocytes.

The vast majority of NHL is of B-cells origin; the remainder is in large part of T-cells tumors.

Tumors of histiocytes or macrophages are quite uncommon.

Histologically, the lymphoma cells exhibit two different growth patterns: they are either clustered into identifiable nodules (nodular lymphoma) or spread diffusely throughout the node (diffuse lymphoma). In general, nodular (or follicular) architecture is associated with a significantly superior prognosis to that of diffuse pattern.

It may be recalled that normal B cells form follicles within lymph nodes; malignant B cells tend to recapitulate this behavior with nodule formation. Not surprisingly, therefore, nodular lymphomas are composed exclusively of B cells.

There are some categories of NHL. Every of this category includes some subtypes of leukemias with their own morphological features:

1.Low-grade.

2.Intermediate-grade.

3.High – grade.

Low-Grade Lymphomas

This category includes three tumors: small lymphocytic lymphoma; follicular, predominantly small cleaved cell lymphoma; and follicular, mixed (small cleaved and large cell) lymphoma.

Small Lymphocytic Lymphoma (SLL)

This pattern makes up approximately 4% of all NHLs and is the only low-grade lymphoma that does not have a follicular architecture.

Microscopically: SLL consists of compact, small, apparently unstimulated lymphocytes with dark-staining round nuclei, scanty cytoplasm, and little variation in size. Mitotic figures are rare, and there is little or no cytologic atypia.

Involvement, of bone marrow to present in almost all cases, and in about 60% of patients the neoplastic cells spill over into blood, evoking a chronic lymphocytic leukemia-like picture.

Follicular Lymphomas

There are two cytologic subgroups of low-grade follicular lymphomas: follicular small cleaved cell and follicular mixed cell type.

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The neoplastic B cells tend to recapitulate normal lymphoid follicles, and hence they resemble the cells seen within normal germinal centers.

Small-cleaved cells are slightly larger than normal lymphocytes, with scanty cytoplasm. The most distinctive feature that differentiates the tumor cells from small normal lymphocytes is their irregular “cleaved” nuclear contour, characterized by prominent clefts, indentations, and linear enfolding.

The nuclear chromatin is coarse and condensed, and nucleoli are indistinct. Mitoses are infrequent.

Follicular, mixed lymphomas constitute a small proportion of all follicular center cell tumors.

Intermediate-Grade Lymphomas

There are four tumors in this category - one with a follicular architecture and the other three with a diffuse pattern. The diffuse intermediate-grade lymphomas are distinguished on the basis of their cellular composition.

Follicular, Predominantly Large Cell Lymphoma.

In contrast to the low-grade follicular lymphomas, the majority of the neoplastic cells are large, with cleaved or noncleaved nuclei. Mitotic figures are also more numerous.

Diffuse Small Cleaved Cell Lymphoma.

This type is composed of small-cleaved cells that are morphologically and phenotypically similar to those that are present in the follicular small-cleaved cell lymphoma.

Diffuse Mixed Small and Large Cell Lymphoma.

These tumors contain a mixture of small cleaved cells already described and large cells that may be cleaved or noncleaved.

The nuclei of large cleaved cells are irregular in contour, indented, and larger than nuclei of normal histiocytes or endothelial cells (often used as a reference in evaluating size).

The nuclear chromatin is slightly more dispersed than in a normal small lymphocyte, and nucleoli are inconspicuous.

The cytoplasm is scant and pale.

Large noncleaved cells are up to four times the size of normal lymphocytes, with a round or oval nucleus and one to two prominent nucleoli; the nuclear chromatin-is vesicular and mitoses are prominent. The amount of cytoplasm is greater than in large cleaved cells and stains pale blue.

Diffuse Large Cell Lymphoma.

This variant is the most common of intermediate-grade lymphomas.

Morphologically, these tumors contain predominantly large cells of the cleaved and noncleaved types described above.

It should be noted that the distinction between diffuse large cell lymphomas and the diffuse mixed variant is difficult and somewhat arbitrary.

High-Grade Lymphomas

There are 3 types of lymphomas in this category: (1) large cell immunoblastic lymphomas; (2) lymphobtastic lymphoma, a tumor that occurs in adolescents and is associated with a characteristic clinical presentation; and (3) small noncleaved lymphomas, which include Burkitt's lymphoma and related B-cell neoplasms.

Large Cell Immunoblastic Lymphoma.

In some cases the tumor cells have plasmacytoid features.

These cells are four to live times larger than small lymphocytes and have a round or oval large nucleus that appears vesicular owing to margination of chromatin at the nuclear membrane. One or two centrally placed prominent nucleoli are usually seen.

In other cases, the turner cells may contain large multilobated (polymorphous) nuclei, or the nucleus may be round with clear cytoplasm.

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Although features such as plasmacytoid appearance and clear cytoplasm or polymorphous nucleus is suggestive of B and T immunoblasts. Respectively, these distinctions are not absolute.

Lymphoblastic Lymphoma

The tumors are fairly uniform in size, with scanty cytoplasm and nuclei that are somewhat larger than those of small lymphocytes.

The nuclear chromatin is delicate and finely stippled, and nucleoli are either absent or inconspicuous.

In keeping with its aggressive growth, the tumor shows a high rate of mitosis, and as with other tumors having a high mitotic rate (e.g., Burkitt's lymphomas), a "starry sky" pattern is produced by the interspersed benign macrophages.

Small Noncleaved Cell Lymphoma.

These tumors consist of a sea of strikingly monotonous cells, with round or oval nuclei containing two to five prominent nucleoli.

The nuclear size approximates that of benign macrophages within the tumor. There is a moderate amount of faintly basophilic cytoplasm, which also is intensely pyroninophilic and often contains small, lipid-filled vacuoles (better appreciated on stained imprints of the tumor).

A high mitotic index is very characteristic, as is cell death, accounting for the presence of numerous tissue macrophages with ingested nuclear debris. Since these benign, macrophages, which are diffusely distributed among the tumor cells are often surrounded by a clear space, they create a “starry sky” pattern.

Hodgkin’s Disease or Lymphogranulomatosis

Hodgkin‟s disease (HD) is a disorder involving primarily the lymphoid tissue. It arises almost invariably in a single node or chain of nodes and spread characteristically to the anatomically contiguous nodes.

It‟s separated from NHL for several reasons.

1.First it is characterized morphologically by the presence of distinctive neoplastic giant cells called Reed-Sternberg’s cells, admixed with a variable inflammatory infiltrate.

2.Second, it is often associated with somewhat distinctive clinical features, including systemic manifestations such as fever. Finally, the target cell of neoplastic transformation has yet to be identified with certainty.

Morphology

A distinctive tumor giant cells known as the Reed-Sternberg cell (RS) is considered to be the essential neoplastic element in all forms of HD, and their identification is essential for the histologic diagnosis.

Classically it is a large cell, most often benucleate or belobed, with two halves often appearing as mirror images of each other.

At other times there are multiple nuclei, or the single nucleus is multilobade and polypoid. The nucleus is enclosed within the abundant amphophilic cytoplasm. Prominent within the nuclei are large, inclusion-like, “owl-eyed” nucleoli generally surrounded by a clear halo.

Variants of RS cells include uninucleated cells with prominent nucleoli, and lacunar cells. The lacunar cell is large with single hyperlobated nucleus containing multiple small nucleoli and an abundant, pale-staining cytoplasm.

The origin of HD is unknown. The accumulated phenotypic and molecular studies suggest that HD is heterogeneous with respect to both the cell type involved and the etiologic agents. The nodular form of lymphocyte predominance type is clearly B-cell neoplasm; others may arise from B-cells or T-cells.

There are some subtypes of HD according to the Rye classification:

1.Lymphocytic predominance HD. Characterized by a diffuse or vaguely nodular infiltrate of mature lymphocytes admixed with variable numbers of benign histiocytes. Scatterd among these cells are the distinctive RS cells. Most patients are under 35 years of age and have an excellent prognosis.

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2.Mixed cellularity HD is a common form of HD. Typical RS cells are plentiful. Usually there is heterogenous cellular infiltrate, which includes eosinophils, plasma cells, and histiocytes.

3.Lymphocyte depletion HD. This uncommon pattern is characterized by a paucity of lymphocytes, RS and their pleomorphic variants, and also massive foci of necrosis and sclerosis. The reticular variant is cellular and contains highly anaplastic, atypical RS cells. Patients are usually older and have a very poor prognosis.

4.Nodular sclerosis HD. In this variant, fine or dense collagenous bands subdivide the lymphoid tissue into circumscribed nodules. There are varying proportions of lacunar cells and lymphocytes; classic RS cells are rare. Most patients are young with an excellent prognosis

The causes of death and complications

1.Renal amyloidosis followed by shrunken kidney and uremia.

2.Intoxication.

3.Septic complications.

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PART II. SYSTEMIC PATHOLOGY

DISEASES OF BLOOD

ANEMIAS

Anemia literary means “without blood, bloodless”, but indeed this term denotes a complicated symptom-complex which is characterized by changes in the number of erythrocytes and reduction of hemoglobin amount in a unit of blood volume.

Anemia is defined as a hemoglobin concentration in blood below the lower limit of the normal range for the age and sex of the individual. In adults, the lower extreme of the normal hemoglobin is taken as 13.0 g/dl for males and 11.5 g/dl for females.

It known that erythrocytes and hemoglobin realize transport oxygen to the tissues. Thus, decrease in the number of erythrocytes may cause oxygen deficiency in the tissues, i.e. hypoxia development.

Not only the degree of anemia but also the rate of its development as well as the degree and quickness of the organism adaptation are important. Physicians often observe discrepancy between the severity of anemia and active condition of the patient, which can be explained by compensation mechanisms, providing physiological need of the tissues in oxygen. Only in cases of severe anemia or at high rate of adaptation, hypoxia may develop.

Numerous neurohumoral factors participate in compensation of anemic state. They stimulate blood and hemopoietic systems. Hypoxia causes appearance of incompletely oxygenated metabolic products, which affect central regulation of blood system as well as neuromuscular apparatus of the heart causing increase in the heart rate and acceleration of the blood flow. As a result, minute blood volume discharged by the left ventricle increases twice (to 8 liters instead of 4). Besides, spasm of peripheral vessels develops in anemia and blood reserves from the tissue depot (mainly from subcutaneous tissue) enter the blood circulation.

Classification of anemias is based on the mechanism of production:

I. Anemia by blood loss (post hemorrhagic).

II. Anemia by impaired red cell production (deficient).

III. Anemia by increased rate of destruction of red blood cells (RBC) - hemolytic anemia.

Morphologically, anemias can be classified on the basis of the size and shape of RBC in peripheral smears and their content of Hb. There are three types of anemias, such as (table 7).

TABLE 7. Classification of anemias

Blood mass in anemia may be normal, increased or decreased. These conditions are called

Normovolemia.

Hypervolemia.

Hypovolemia.

I. The anemia by blood loss (Posthemorrhagic anemias)

The anemia by blood loss (Posthemorrhagic anemias) is caused by the blood loss in traumas, pathological processes, accompanied by damage of the vessel or hemorrhage from the inner organs. Depending on the size of the injured vessel and the rate of the blood loss it may be acute or chronic.

Acute posthemorrhagic anemia

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Examples:

Massive hemorrhage from the vessels of the stomach and intestine in ulcer of the stomach and duodenum.

From the ulcers in typhoid fever.

In ectopic (tubal) pregnancy.

Pulmonary hemorrhage in tuberculosis.

Rupture of aortic aneurysm.

Rupture of the heart walls due to transmural infarction.

In rupture of the aortic arch, loss of less than 1 liter of blood causes death due to sudden drop in arterial pressure. The death occurs before exsanguinations of the organism; therefore anemia in the organs is not marked. In hemorrhages from small vessels, death occurs when half of the blood is lost.

Morphological signs of hemorrhage:

Pallor of skin and internal organs, collapse signs.

In case of the fatal hemorrhage, the smallest hemorrhages (petechia) occur under endocardium of the left ventricle (Minakov’s streaks).

If the hemorrhage is not fatal, the blood loss is compensated due to regeneration processes, taking place in the tissue of the bone marrow. The bone marrow of the flat bones proliferates and becomes bright. The yellow bone marrow replaced by red (hemopoetic) one.

In repeated hemorrhages, extramedullary hemopoesis may take place in the spleen, liver, lymphatic nodes and other organs.

The prognosis of the hemorrhagic anemia depends on the rate of blood flow:

Rapid blood loss of 1/4 of the total blood volume may cause shock.

Loss of 1/2 of the total blood volume is incompatible with the life.

Loss of 3/4 of the total circulating blood does not cause death if it occurs slowly during several days.

In healthy persons, even at considerable blood loss, its composition restores in 4 - 5 weeks.

Chronic post hemorrhagic anemia

This frequently develops after long, repeated slow blood loss, in the majority of cases at hemorrhages from gastrointestinal tract (ulcer, cancer, hemorrhoids), uterine bleedings, in hemophilia, hemorrhagic diathesis, in ankylospondylosis.

A clinic-morphological signs of anemia are a pale skin and visceral organs. In some cases, the source of hemorrhage is inconsiderable and very difficult to reveal. Severe irondeficiency anemia develops.

II.Anemias impaired red cell production (deficiency anemias)

The anemia appearing as a result of breach of hemopoesis is called by three ways:

a)deficient anemia,

b)impaired red cell production,

c)anemia of diminished erythropoesis.

Diminished erythropoiesis may be the result of deficiency of some vital substrate necessary for red cell formation.

Included in this group are:

a)Cytoplasmic maturation defects.

1.Deficient hem synthesis: Iron deficiency anemia.

2.Deficient globin synthesis: Thalassemic syndromes.

b)Nuclear maturation defects.

1.Vitamin B12 and/or folic acid deficiency: Megaloblastic anemia.

c)Defect in stem cell proliferation and differentiation.

1.Aplastic anemia.

2.Pure red cell aplasia:

Anemia of chronic disorders.

Bone marrow infiltration.

Congenital anemia.

Iron deficiency anemia

Iron obtained from diet showed replace its loss (about 1 mg daily) in an adult male or in a non-menstruating female, while in a menstruating woman there is an additional iron loss of 0.5-1 mg daily.