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Pathology - Acute myeloid leukemia
Definition: A collection of hematological neoplasms consisting of malignant myeloid blasts.
Epidemiology The global incidence is 3 cases per 100,000 individuals annually. • Primarily, a condition affecting adults (average age at diagnosis is 65 years).
Aetiology • Acute myeloid leukaemias (AML) can be either spontaneous or arise as a consequence of prior treatment or as a final manifestation of an existing myeloproliferative or myelodysplastic disorder.
Pathogenesis • Mutations in a hematopoietic stem cell result in the clonal proliferation of immature myeloid blasts. • Rapidly proliferating myeloid blasts saturate the bone marrow and enter the peripheral blood. • Infiltration of organs by myeloid blasts may occur in acute myeloid leukemia (AML), although this is less frequent than in acute B-lymphoblastic leukemia.
Presentation • The majority of patients manifest as bone marrow failure, resulting in anaemia, thrombocytopenia, and neutropenia. Leukocytosis may be present.
Microscopy • By definition, over 20% of the cells in peripheral blood or bone marrow are myeloid blasts. • The blasts are medium to large cells characterized by a high nuclear-to-cytoplasmic ratio. Certain myeloid blasts possess cytoplasmic granules or Auer rods. Immunophenotype • Myeloid blasts typically exhibit expression of CD13, CD117, CD33, and CD34. • They lack expression of B-lymphoid markers, including CD79a.
The prognosis is contingent upon the specific subtype of AML; still, the majority are aggressive conditions necessitating rigorous ablative treatments to attain remission. Acute myeloid leukemia (AML) linked to prior treatment or an existing myeloid disease typically exhibits a dismal prognosis.
Definition: A collection of hematological neoplasms consisting of malignant myeloid blasts.
Epidemiology The global incidence is 3 cases per 100,000 individuals annually. • Primarily, a condition affecting adults (average age at diagnosis is 65 years).
Aetiology • Acute myeloid leukaemias (AML) can be either spontaneous or arise as a consequence of prior treatment or as a final manifestation of an existing myeloproliferative or myelodysplastic disorder.
Pathogenesis • Mutations in a hematopoietic stem cell result in the clonal proliferation of immature myeloid blasts. • Rapidly proliferating myeloid blasts saturate the bone marrow and enter the peripheral blood. • Infiltration of organs by myeloid blasts may occur in acute myeloid leukemia (AML), although this is less frequent than in acute B-lymphoblastic leukemia.
Presentation • The majority of patients manifest as bone marrow failure, resulting in anaemia, thrombocytopenia, and neutropenia. Leukocytosis may be present.
Microscopy • By definition, over 20% of the cells in peripheral blood or bone marrow are myeloid blasts. • The blasts are medium to large cells characterized by a high nuclear-to-cytoplasmic ratio. Certain myeloid blasts possess cytoplasmic granules or Auer rods. Immunophenotype • Myeloid blasts typically exhibit expression of CD13, CD117, CD33, and CD34. • They lack expression of B-lymphoid markers, including CD79a.
The prognosis is contingent upon the specific subtype of AML; still, the majority are aggressive conditions necessitating rigorous ablative treatments to attain remission. Acute myeloid leukemia (AML) linked to prior treatment or an existing myeloid disease typically exhibits a dismal prognosis.
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Pathology - Chronic lymphocytic leukemia
A malignant tumor consisting of tiny mature B-cells that typically coexpress CD5 and CD23.
Epidemiology The predominant leukemia, occurring at a rate of 5 per 100,000 individuals. • A condition prevalent among older persons, with a peak incidence occurring between the ages of 60 and 80 years. • Males are impacted twice as frequently as females.
Aetiology • Unidentified.
Pathogenesis The oncogenic B-cells progressively infiltrate the bone marrow and subsequently enter the peripheral circulation. • As the condition advances, lymph nodes become affected, followed by the liver and spleen. • In the terminal phases of the disease, the neoplastic cells dominate the bone marrow, resulting in bone marrow failure.
Presentation • Numerous people are diagnosed incidentally when a complete blood count indicates leukocytosis. The remainder exhibits lymphadenopathy or autoimmune manifestations, such autoimmune hemolytic anemia or autoimmune thrombocytopenia.
Peripheral blood film: Excess of mature lymphocytes. Smear cells are indicative of chronic lymphocytic leukaemia (CLL); they are neoplastic cells that get blurred during film preparation. Histopathology • Lymph nodes are substituted by small, slightly atypical B-cells exhibiting varied quantities of proliferation centers comprising bigger lymphoid cells. • Affected bone marrow contains aggregates of neoplastic lymphoid cells. Immunophenotype: Positive for PAX5, CD20, CD79a, CD5, and CD23. • Cyclin D1 is negative.
Prognosis • Typically exhibits an indolent course, with several patients surviving for several years post-diagnosis, frequently without intervention. • A minority of cases are compounded by the emergence of diffuse large B-cell lymphoma (Richter’s syndrome), which carries a bad prognosis.
A malignant tumor consisting of tiny mature B-cells that typically coexpress CD5 and CD23.
Epidemiology The predominant leukemia, occurring at a rate of 5 per 100,000 individuals. • A condition prevalent among older persons, with a peak incidence occurring between the ages of 60 and 80 years. • Males are impacted twice as frequently as females.
Aetiology • Unidentified.
Pathogenesis The oncogenic B-cells progressively infiltrate the bone marrow and subsequently enter the peripheral circulation. • As the condition advances, lymph nodes become affected, followed by the liver and spleen. • In the terminal phases of the disease, the neoplastic cells dominate the bone marrow, resulting in bone marrow failure.
Presentation • Numerous people are diagnosed incidentally when a complete blood count indicates leukocytosis. The remainder exhibits lymphadenopathy or autoimmune manifestations, such autoimmune hemolytic anemia or autoimmune thrombocytopenia.
Peripheral blood film: Excess of mature lymphocytes. Smear cells are indicative of chronic lymphocytic leukaemia (CLL); they are neoplastic cells that get blurred during film preparation. Histopathology • Lymph nodes are substituted by small, slightly atypical B-cells exhibiting varied quantities of proliferation centers comprising bigger lymphoid cells. • Affected bone marrow contains aggregates of neoplastic lymphoid cells. Immunophenotype: Positive for PAX5, CD20, CD79a, CD5, and CD23. • Cyclin D1 is negative.
Prognosis • Typically exhibits an indolent course, with several patients surviving for several years post-diagnosis, frequently without intervention. • A minority of cases are compounded by the emergence of diffuse large B-cell lymphoma (Richter’s syndrome), which carries a bad prognosis.
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Pathology - Chronic myelogenous leukemia
A myeloproliferative neoplasm mostly affecting the granulocytic lineage, consistently related with the BCR-ABL1 fusion gene on the Philadelphia chromosome.
Epidemiology • Incidence ranges from 1 to 2 per 100,000 individuals annually. • The peak age of onset is between 50 and 70 years old.
Aetiology: Unknown. Genetics • Chronic myelogenous leukaemia (CML) is typically characterized by the t(9;22) translocation, which produces the Philadelphia chromosome. • This translocation fuses the BCR gene on chromosome 22 with the ABL1 gene on chromosome 9. • The resulting BCR-ABL1 protein exhibits increased tyrosine kinase activity, resulting in the persistent activation of signal transduction pathways and uncontrolled proliferation of myeloid cells.
Presentation • The majority of patients receive a diagnosis during the chronic phase of the disease, characterized by an elevated white cell count. • Hepatosplenomegaly frequently accompanies the diagnosis.
Peripheral blood • Leukocytosis resulting from elevated neutrophil counts at various maturation phases. • Basophilia and eosinophilia are prevalent. No dysplasia is observed.
Bone marrow • Bone marrow trephines exhibit hypercellularity attributed to elevated quantities of neutrophils and their precursors. • Megakaryocytes are generally diminutive and hypolobated. • Blasts constitute less than 5% of marrow cells throughout the chronic phase.
Prognosis • The outcome has significantly improved following the introduction of the tyrosine kinase inhibitor, imatinib, resulting in 5-year survival rates of 80–90%. • Disease progression is typically indicated by an elevation in circulating blasts to over 10% (accelerated phase) and culminates in acute leukemia when blasts constitute more than 20% of circulating cells.
A myeloproliferative neoplasm mostly affecting the granulocytic lineage, consistently related with the BCR-ABL1 fusion gene on the Philadelphia chromosome.
Epidemiology • Incidence ranges from 1 to 2 per 100,000 individuals annually. • The peak age of onset is between 50 and 70 years old.
Aetiology: Unknown. Genetics • Chronic myelogenous leukaemia (CML) is typically characterized by the t(9;22) translocation, which produces the Philadelphia chromosome. • This translocation fuses the BCR gene on chromosome 22 with the ABL1 gene on chromosome 9. • The resulting BCR-ABL1 protein exhibits increased tyrosine kinase activity, resulting in the persistent activation of signal transduction pathways and uncontrolled proliferation of myeloid cells.
Presentation • The majority of patients receive a diagnosis during the chronic phase of the disease, characterized by an elevated white cell count. • Hepatosplenomegaly frequently accompanies the diagnosis.
Peripheral blood • Leukocytosis resulting from elevated neutrophil counts at various maturation phases. • Basophilia and eosinophilia are prevalent. No dysplasia is observed.
Bone marrow • Bone marrow trephines exhibit hypercellularity attributed to elevated quantities of neutrophils and their precursors. • Megakaryocytes are generally diminutive and hypolobated. • Blasts constitute less than 5% of marrow cells throughout the chronic phase.
Prognosis • The outcome has significantly improved following the introduction of the tyrosine kinase inhibitor, imatinib, resulting in 5-year survival rates of 80–90%. • Disease progression is typically indicated by an elevation in circulating blasts to over 10% (accelerated phase) and culminates in acute leukemia when blasts constitute more than 20% of circulating cells.
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Pathology - Polycythemia vera
A myeloproliferative neoplasm primarily affecting the erythroid lineage, typically linked to a somatic gain-of-function mutation in the JAK2 gene. Epidemiology: Incidence ranges from 1 to 2.5 cases per 100,000 individuals annually. The median age upon diagnosis is 60 years. • There is a minor masculine predominance.
Aetiology: Unknown. Genetics: Over 95% of cases exhibit the JAK2 V617F mutation, resulting in uncontrolled proliferation of all myeloid cells, particularly affecting the erythroid lineage. The advancement of the disease correlates with the development of chromosomal abnormalities.
Presentation • May be incidentally detected with a full blood count or manifest with symptoms associated with hyperviscosity (headache, dizziness, visual disturbances, venous or arterial thrombosis). • The majority of individuals exhibit plethoric conditions and hepatosplenomegaly. Complete blood count: elevated hemoglobin, increased red cell count, heightened hematocrit (HCT), and augmented packed cell volume (PCV). • Frequently, I monitor white blood cell count and platelet levels. The bone marrow exhibits hypercellularity resulting from an elevation in all myeloid lineages, termed 'panmyelosis.' Erythroid progenitors and megakaryocytes are the most prominent cell types. Megakaryocytes exhibit loose clustering and frequently demonstrate considerable variation in size and morphology.
Prognosis: Median survival exceeds 10 years with treatment. The majority of patients succumb to thrombosis or hemorrhage. Approximately 20% succumb to the progression of myelodysplasia or acute myeloid leukemia (AML).
A myeloproliferative neoplasm primarily affecting the erythroid lineage, typically linked to a somatic gain-of-function mutation in the JAK2 gene. Epidemiology: Incidence ranges from 1 to 2.5 cases per 100,000 individuals annually. The median age upon diagnosis is 60 years. • There is a minor masculine predominance.
Aetiology: Unknown. Genetics: Over 95% of cases exhibit the JAK2 V617F mutation, resulting in uncontrolled proliferation of all myeloid cells, particularly affecting the erythroid lineage. The advancement of the disease correlates with the development of chromosomal abnormalities.
Presentation • May be incidentally detected with a full blood count or manifest with symptoms associated with hyperviscosity (headache, dizziness, visual disturbances, venous or arterial thrombosis). • The majority of individuals exhibit plethoric conditions and hepatosplenomegaly. Complete blood count: elevated hemoglobin, increased red cell count, heightened hematocrit (HCT), and augmented packed cell volume (PCV). • Frequently, I monitor white blood cell count and platelet levels. The bone marrow exhibits hypercellularity resulting from an elevation in all myeloid lineages, termed 'panmyelosis.' Erythroid progenitors and megakaryocytes are the most prominent cell types. Megakaryocytes exhibit loose clustering and frequently demonstrate considerable variation in size and morphology.
Prognosis: Median survival exceeds 10 years with treatment. The majority of patients succumb to thrombosis or hemorrhage. Approximately 20% succumb to the progression of myelodysplasia or acute myeloid leukemia (AML).
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Pathology - Essential thrombocythemia
Definition: A myeloproliferative neoplasm mostly affecting the megakaryocytic lineage.
Epidemiology: Estimated incidence ranges from 0.5 to 2.5 cases per 100,000 individuals annually. • The majority of occurrences occur in adults aged 50 to 60. • There is no gender preference.
Aetiology: Unknown. Genetics • No established molecular genetic or cytogenetic abnormalities have been identified.
Presentation • Approximately fifty percent of patients are diagnosed incidentally due to a significantly elevated platelet count identified in a complete blood count. • The remaining patients exhibit symptoms associated with vascular occlusion or hemorrhage, including transient ischemic attacks, digital ischemia and gangrene, as well as major arterial and venous thrombosis. • Splenomegaly occurs in only a minority of patients. Complete blood count • Persistently high platelet count (> 450 × 10^9/L). The leukocyte and erythrocyte counts are typically within normal limits. The bone marrow has normal cellularity, although displays an elevated presence of huge and enormous megakaryocytes characterized by ample cytoplasm and severely lobated 'stag-horn' nuclei. There is no significant proliferation of erythroid or granulocytic lineages.
Prognosis: A rather indolent disease with a median survival of 10 to 15 years. • A minimal percentage of patients advance to bone marrow fibrosis or acute myeloid leukemia.
Definition: A myeloproliferative neoplasm mostly affecting the megakaryocytic lineage.
Epidemiology: Estimated incidence ranges from 0.5 to 2.5 cases per 100,000 individuals annually. • The majority of occurrences occur in adults aged 50 to 60. • There is no gender preference.
Aetiology: Unknown. Genetics • No established molecular genetic or cytogenetic abnormalities have been identified.
Presentation • Approximately fifty percent of patients are diagnosed incidentally due to a significantly elevated platelet count identified in a complete blood count. • The remaining patients exhibit symptoms associated with vascular occlusion or hemorrhage, including transient ischemic attacks, digital ischemia and gangrene, as well as major arterial and venous thrombosis. • Splenomegaly occurs in only a minority of patients. Complete blood count • Persistently high platelet count (> 450 × 10^9/L). The leukocyte and erythrocyte counts are typically within normal limits. The bone marrow has normal cellularity, although displays an elevated presence of huge and enormous megakaryocytes characterized by ample cytoplasm and severely lobated 'stag-horn' nuclei. There is no significant proliferation of erythroid or granulocytic lineages.
Prognosis: A rather indolent disease with a median survival of 10 to 15 years. • A minimal percentage of patients advance to bone marrow fibrosis or acute myeloid leukemia.
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Pathology - Primary myelofibrosis
A myeloproliferative neoplasm distinguished by the predominant proliferation of megakaryocytes and granulocytes in the bone marrow, accompanied by reactive deposition of fibrous connective tissue and extramedullary hematopoiesis.
Epidemiology • Estimated yearly incidence ranges from 0.5 to 1.5 per 100,000 individuals. • Predominantly affects people aged 60 to 70, with no discernible gender preference. Aetiology • Predominantly unknown in the majority of instances. Genetics • No specific genetic anomaly has been identified.
Presentation: Abdominal discomfort resulting from significant splenomegaly. • Nocturnal hyperhidrosis, pyrexia, and weight reduction.
Peripheral blood • Increased platelets and/or white cell count. • Decreased hemoglobin. The blood film exhibits leukoerythroblastosis characterized by teardrop-shaped red blood cells. Bone marrow • Megakaryocytes exhibit significant abnormalities characterized by extensive clustering and pronounced cytological atypia. • Progression is accompanied by an increase in marrow fibrosis.
Prognosis • Survival is contingent upon the degree of marrow fibrosis at the time of diagnosis. Patients exhibiting significant fibrosis have median survival durations of 3 to 7 years. The primary causes of mortality are bone marrow failure, thromboemboli, and the onset of acute myeloid leukemia (AML).
A myeloproliferative neoplasm distinguished by the predominant proliferation of megakaryocytes and granulocytes in the bone marrow, accompanied by reactive deposition of fibrous connective tissue and extramedullary hematopoiesis.
Epidemiology • Estimated yearly incidence ranges from 0.5 to 1.5 per 100,000 individuals. • Predominantly affects people aged 60 to 70, with no discernible gender preference. Aetiology • Predominantly unknown in the majority of instances. Genetics • No specific genetic anomaly has been identified.
Presentation: Abdominal discomfort resulting from significant splenomegaly. • Nocturnal hyperhidrosis, pyrexia, and weight reduction.
Peripheral blood • Increased platelets and/or white cell count. • Decreased hemoglobin. The blood film exhibits leukoerythroblastosis characterized by teardrop-shaped red blood cells. Bone marrow • Megakaryocytes exhibit significant abnormalities characterized by extensive clustering and pronounced cytological atypia. • Progression is accompanied by an increase in marrow fibrosis.
Prognosis • Survival is contingent upon the degree of marrow fibrosis at the time of diagnosis. Patients exhibiting significant fibrosis have median survival durations of 3 to 7 years. The primary causes of mortality are bone marrow failure, thromboemboli, and the onset of acute myeloid leukemia (AML).
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Pathology - Myelodysplastic syndromes
Definition: A collection of hematopoietic neoplasms distinguished by dysplasia in one or more myeloid cell lineages, accompanied by inefficient myelopoiesis, cytopenias, and an elevated risk of acute myeloid leukemia (AML) development.
Epidemiology • Estimated yearly incidence ranges from 3 to 5 per 100,000 individuals. • Predominantly affects older adults, with a median age of 70 years.
Aetiology • Predominantly unknown in the majority of instances. Genetics • Several recurrent chromosomal abnormalities have been identified in myelodysplastic syndromes (MDS). Cytogenetic and molecular analyses are essential for establishing clonality and assessing prognosis.
Presentation • Refractory anaemia is the predominant manifestation. • Neutropenia and thrombocytopenia occur with lesser frequency. 2 Hepatosplenomegaly is rare in myelodysplastic syndromes. Peripheral blood • Cytopenias affecting one or more myeloid lineages. • Blood films may reveal macrocytes and atypical neutrophils with poorly developed nuclear segmentation and hypogranular cytoplasm. Bone Marrow • Morphological indicators of myelodysplasia may be observed in one or more myeloid lineages within the bone marrow. • Dyserythropoiesis is defined by nuclear budding, internuclear bridging, karyorrhexis, multinuclearity, nuclear hypolobulation, megaloblastic alterations, ring sideroblasts, and cytoplasmic vacuolization. • Dysgranulopoiesis is characterized by reduced size, nuclear hypolobation, irregular hypersegmentation, and cytoplasmic hypogranularity. • Dysmegakaryocytopoiesis is marked by reduced size, nuclear hypolobation, or multinucleation.
Prognosis: Survival is contingent upon various criteria, including morphological subtype, karyotype, degree of cytopenia, and age. • Low-risk variants of MDS exhibit a protracted natural history and demonstrate a minimal incidence of progression to AML. • High-risk variants are more aggressive, with numerous individuals rapidly succumbing to bone marrow loss or AML.
Definition: A collection of hematopoietic neoplasms distinguished by dysplasia in one or more myeloid cell lineages, accompanied by inefficient myelopoiesis, cytopenias, and an elevated risk of acute myeloid leukemia (AML) development.
Epidemiology • Estimated yearly incidence ranges from 3 to 5 per 100,000 individuals. • Predominantly affects older adults, with a median age of 70 years.
Aetiology • Predominantly unknown in the majority of instances. Genetics • Several recurrent chromosomal abnormalities have been identified in myelodysplastic syndromes (MDS). Cytogenetic and molecular analyses are essential for establishing clonality and assessing prognosis.
Presentation • Refractory anaemia is the predominant manifestation. • Neutropenia and thrombocytopenia occur with lesser frequency. 2 Hepatosplenomegaly is rare in myelodysplastic syndromes. Peripheral blood • Cytopenias affecting one or more myeloid lineages. • Blood films may reveal macrocytes and atypical neutrophils with poorly developed nuclear segmentation and hypogranular cytoplasm. Bone Marrow • Morphological indicators of myelodysplasia may be observed in one or more myeloid lineages within the bone marrow. • Dyserythropoiesis is defined by nuclear budding, internuclear bridging, karyorrhexis, multinuclearity, nuclear hypolobulation, megaloblastic alterations, ring sideroblasts, and cytoplasmic vacuolization. • Dysgranulopoiesis is characterized by reduced size, nuclear hypolobation, irregular hypersegmentation, and cytoplasmic hypogranularity. • Dysmegakaryocytopoiesis is marked by reduced size, nuclear hypolobation, or multinucleation.
Prognosis: Survival is contingent upon various criteria, including morphological subtype, karyotype, degree of cytopenia, and age. • Low-risk variants of MDS exhibit a protracted natural history and demonstrate a minimal incidence of progression to AML. • High-risk variants are more aggressive, with numerous individuals rapidly succumbing to bone marrow loss or AML.
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Pathology – Eczemas
Definition • A collection of inflammatory dermatoses clinically identified by an erythematous papulovesicular eruption and histologically defined by intraepidermal edema (spongiosis).
Atopic dermatitis • Chronic dermatitis prevalent in individuals with atopy. • A highly prevalent condition with incidence rates reaching up to 15%. • Generally manifests in newborns and children. • Clinically induces a pruritic erythematous papulovesicular eruption affecting the facial region and the extensor surfaces of the upper and lower limbs. Biopsies from acute lesions reveal epidermal spongiosis and dermal inflammation. Biopsies from subsequent lesions demonstrate epidermal thickening and hyperkeratosis accompanied by moderate spongiosis.
Contact dermatitis due to irritants • Inflammatory dermatosis induced by the direct toxic impact of an irritant. • A prevalent etiology of occupational dermatosis. • Clinically induces erythema accompanied by vesiculation. Biopsies reveal epidermal spongiosis and dermal inflammation.
Allergic contact dermatitis • Inflammatory dermatosis resulting from a delayed-type hypersensitivity response to an allergen to which the patient has been exposed. • A prevalent occupational dermatosis, notably documented among hairdressers. • Clinically induces pruritic papules and vesicles 12–48 hours post-exposure. • Frequent offenders comprise nickel, cosmetics, and edibles. Biopsies reveal epidermal spongiosis accompanied by vesicle development and an inflammatory infiltrate, typically including eosinophils.
Nummular dermatitis • Inflammatory dermatosis of indeterminate etiology. • Clinically presents as small papules and vesicles that merge into coin-shaped plaques. • Biopsies reveal epidermal spongiosis and inflammation in first lesions. Advanced lesions exhibit epidermal hyperplasia.
Seborrheic dermatitis • Prevalent inflammatory dermatological condition impacting 1–3% of the population. Evidence indicates it may stem from an atypical immunological response to Malassezia organisms, though this remains contentious. • Clinically presents with erythematous, scaly papules and plaques, occasionally exhibiting a greasy look, located on the scalp, ears, eyebrows, and nasolabial region. Biopsies reveal varied epidermal spongiosis and hyperplasia accompanied by overlaying parakeratosis centered on hair follicles.
Definition • A collection of inflammatory dermatoses clinically identified by an erythematous papulovesicular eruption and histologically defined by intraepidermal edema (spongiosis).
Atopic dermatitis • Chronic dermatitis prevalent in individuals with atopy. • A highly prevalent condition with incidence rates reaching up to 15%. • Generally manifests in newborns and children. • Clinically induces a pruritic erythematous papulovesicular eruption affecting the facial region and the extensor surfaces of the upper and lower limbs. Biopsies from acute lesions reveal epidermal spongiosis and dermal inflammation. Biopsies from subsequent lesions demonstrate epidermal thickening and hyperkeratosis accompanied by moderate spongiosis.
Contact dermatitis due to irritants • Inflammatory dermatosis induced by the direct toxic impact of an irritant. • A prevalent etiology of occupational dermatosis. • Clinically induces erythema accompanied by vesiculation. Biopsies reveal epidermal spongiosis and dermal inflammation.
Allergic contact dermatitis • Inflammatory dermatosis resulting from a delayed-type hypersensitivity response to an allergen to which the patient has been exposed. • A prevalent occupational dermatosis, notably documented among hairdressers. • Clinically induces pruritic papules and vesicles 12–48 hours post-exposure. • Frequent offenders comprise nickel, cosmetics, and edibles. Biopsies reveal epidermal spongiosis accompanied by vesicle development and an inflammatory infiltrate, typically including eosinophils.
Nummular dermatitis • Inflammatory dermatosis of indeterminate etiology. • Clinically presents as small papules and vesicles that merge into coin-shaped plaques. • Biopsies reveal epidermal spongiosis and inflammation in first lesions. Advanced lesions exhibit epidermal hyperplasia.
Seborrheic dermatitis • Prevalent inflammatory dermatological condition impacting 1–3% of the population. Evidence indicates it may stem from an atypical immunological response to Malassezia organisms, though this remains contentious. • Clinically presents with erythematous, scaly papules and plaques, occasionally exhibiting a greasy look, located on the scalp, ears, eyebrows, and nasolabial region. Biopsies reveal varied epidermal spongiosis and hyperplasia accompanied by overlaying parakeratosis centered on hair follicles.
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Pathology - Plasma cell myeloma
Definition: A diffuse neoplasm of plasma cells originating from bone marrow, characterized by the presence of paraproteins in serum and/or urine.
Epidemiology • Incidence ranges from 3 to 5 per 100,000 individuals. •
Manifestations are observed in older persons, with a mean diagnostic age of 70 years. • There is a masculine predominance of 1.5:1.
Aetiology • Unidentified.
Pathogenesis The neoplastic plasma cells produce cytokines that activate osteoclasts, resulting in lytic bone lesions. Circulating paraprotein inhibits normal immunoglobulin synthesis, hence elevating the susceptibility to infections. Free light chains traversing the kidneys contribute to renal failure.
Presentation: • Ostealgia and recurring infections. • Anemia, elevated ESR, hypercalcemia, and renal dysfunction are prevalent.
Histopathology A definitive diagnosis necessitates a bone marrow biopsy. • The bone marrow exhibits an abundance of monoclonal plasma cells organized in clusters, nodules, or sheets. • Clonality can be confirmed immunohistochemically by demonstrating kappa or lambda light chain restriction.
Prognosis • Myeloma is an incurable condition. • Average survival is 3–4 years post-diagnosis.
Definition: A diffuse neoplasm of plasma cells originating from bone marrow, characterized by the presence of paraproteins in serum and/or urine.
Epidemiology • Incidence ranges from 3 to 5 per 100,000 individuals. •
Manifestations are observed in older persons, with a mean diagnostic age of 70 years. • There is a masculine predominance of 1.5:1.
Aetiology • Unidentified.
Pathogenesis The neoplastic plasma cells produce cytokines that activate osteoclasts, resulting in lytic bone lesions. Circulating paraprotein inhibits normal immunoglobulin synthesis, hence elevating the susceptibility to infections. Free light chains traversing the kidneys contribute to renal failure.
Presentation: • Ostealgia and recurring infections. • Anemia, elevated ESR, hypercalcemia, and renal dysfunction are prevalent.
Histopathology A definitive diagnosis necessitates a bone marrow biopsy. • The bone marrow exhibits an abundance of monoclonal plasma cells organized in clusters, nodules, or sheets. • Clonality can be confirmed immunohistochemically by demonstrating kappa or lambda light chain restriction.
Prognosis • Myeloma is an incurable condition. • Average survival is 3–4 years post-diagnosis.
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Pathology - Primary amyloidosis
Definition: A plasma cell neoplasm characterized by the accumulation of AL amyloid in several tissues.
Epidemiology • Uncommon ailment. The median age at diagnosis is 65 years, with a predominance of males.
Aetiology The majority of patients possess an underlying plasma cell neoplasm yet do not fulfill the diagnostic criteria for plasma cell myeloma. Pathogenesis • AL amyloid consists of immunoglobulin light chains produced by monoclonal plasma cells, which aggregate in diverse tissues in a β-pleated sheet configuration. • The deposited amyloid comprises both intact light chains and fragments of the variable NH2-terminal region.
Presentation • Clinical manifestations associated with amyloid accumulation in several organs. Commonly affected areas encompass the skin, kidneys, heart, liver, intestines, and peripheral nerves. Characteristic manifestations include purpura, peripheral neuropathy, cardiac insufficiency, nephrotic syndrome, and malabsorption.
Histopathology • Amyloid can be identified in several tissues as a pink, amorphous material. The Congo Amyloid exhibits red staining under ordinary light microscopy and 'apple green' under polarized light. Bone marrow biopsies generally reveal a little elevation in plasma cells, which may present as either normal or abnormal. The plasma cells exhibit monotypism for either kappa or lambda light chains.
Prognosis: • Dismal prognosis with a median survival of merely 2 years from diagnosis. The predominant cause of mortality is amyloid-related heart failure.
Definition: A plasma cell neoplasm characterized by the accumulation of AL amyloid in several tissues.
Epidemiology • Uncommon ailment. The median age at diagnosis is 65 years, with a predominance of males.
Aetiology The majority of patients possess an underlying plasma cell neoplasm yet do not fulfill the diagnostic criteria for plasma cell myeloma. Pathogenesis • AL amyloid consists of immunoglobulin light chains produced by monoclonal plasma cells, which aggregate in diverse tissues in a β-pleated sheet configuration. • The deposited amyloid comprises both intact light chains and fragments of the variable NH2-terminal region.
Presentation • Clinical manifestations associated with amyloid accumulation in several organs. Commonly affected areas encompass the skin, kidneys, heart, liver, intestines, and peripheral nerves. Characteristic manifestations include purpura, peripheral neuropathy, cardiac insufficiency, nephrotic syndrome, and malabsorption.
Histopathology • Amyloid can be identified in several tissues as a pink, amorphous material. The Congo Amyloid exhibits red staining under ordinary light microscopy and 'apple green' under polarized light. Bone marrow biopsies generally reveal a little elevation in plasma cells, which may present as either normal or abnormal. The plasma cells exhibit monotypism for either kappa or lambda light chains.
Prognosis: • Dismal prognosis with a median survival of merely 2 years from diagnosis. The predominant cause of mortality is amyloid-related heart failure.
