Pathology Quiz: Tumors and Anemias

Tumors

• Benign tumors: slow-growing, well-defined capsule, non-invasive, well-differentiated, low mitotic index, no metastasis
• Malignant tumors: fast-growing, not encapsulated, invasive, poorly differentiated, high mitotic index, able to metastasize

Anemias

Pernicious Anemia

• Autoimmune disorder: anti-IF or anti-parietal cell antibodies
• Manifestations: bleeding gums, diarrhea, impaired smell, loss of deep tendon reflexes, anorexia, personality or memory changes, positive Babinski's sign, stomatitis, paresthesia, and unsteady gait
• Diagnosis: CBC, serum B12 levels, antibody presence, gastric analysis, folate (Schilling's test, bone marrow biopsy)
• Treatment: injectable B12 (bypassing GI tract absorption)

Megaloblastic Anemia

• Folate and VitB12 are required for DNA synthesis, leading to decreased maturation and cell division
• Causes: decreased intake from diet, gastric dysfunction, celiac sprue, autoimmune (anti-IF or anti-parietal cell antibodies)
• May see myelin breakdown and neurological complications

Macrocytic Anemia

• Characterized by large red blood cells

Aplastic Anemia

• Pancytopenia: bone marrow depression of all blood cells, damage to PSC
• Causes: insidious, other anemias, autoimmune, medications, medical treatments, viruses, cancer, and genetic
• Onset may be insidious or sudden and severe
• Manifestations: anemia, leukocytopenia, thrombocytopenia
• Diagnosis: complete blood count and bone marrow biopsy
• Treatment: identify and manage underlying cause, oxygen therapy, infection control and treatment, bleeding precautions, blood transfusions, and bone marrow transplants

Sickle Cell Anemia

• Autosomal recessive inheritance, abnormal hemoglobin "S" (one AA substitution)
• HgbS causes RBC to become abnormally shaped/sickled under low oxygen conditions, leading to tissue hypoxia and ischemia
• More common in people of African and Mediterranean descent
• Manifestations: appear as early as 6 months of age, sickle cell crisis, painful episodes, tissue ischemia and necrosis, triggered by dehydration, stress, infection, high altitudes, and fever
• Diagnosis: CBC, sickle solubility (screen), hemoglobin electrophoresis, CMP
• Treatment: no cure, palliative, exceptions: stem cell or bone marrow transplant, gene therapy under research

Hemolytic Anemia

• Excessive erythrocyte destruction, reticulocyte production index is high
• Causes: idiopathic, autoimmune, genetics, infections, blood transfusion reactions, and blood incompatibility in the neonate
• Several types: hemoglobinopathies (sickle cell anemia), thalassemia, RBC membrane or enzyme defects, immune (erythroblastosis fetalis) and non-immune hemolytic anemia

Lymphomas

• Cancers originate in lymphatic system, affecting WBCs as well
• Most common hematologic cancer in the US
• Two main types:
  • Hodgkin lymphoma: B cells
  • Non-Hodgkin lymphoma: B cells, T cells, NK cells

Hodgkin Lymphoma

• Lesser common of the two
• Solid tumors with the presence of Reed-Sternberg cells
• Typically originate in the lymph nodes of the upper body
• Several subtypes
• Amenable to cure
• Manifestations: painless enlarged lymph nodes, weight loss, fever, night sweats, pruritus, coughing, difficulty breathing, chest pain, recurrent infections
• Diagnosis: physical examination, presence of Reed-Sternberg cells in a lymph node biopsy, CBC, chest X-rays, CT-scan, MRI, PET scan, and bone marrow biopsy
• Treatment: chemotherapy, radiation, and surgery

Non-Hodgkin Lymphoma

• More common
• Poor prognosis
• Many different types
• Similar to Hodgkin manifestations, staging, and treatment
• Different in the spread and diagnosis
• Can originate in the T or B cells
• No Reed-Sternberg cells

Leukemia

• Manifestations: leukopenia, leukocytosis, anemia, thrombocytopenia, lymphadenopathy, joint swelling, bone pain, weight loss, anorexia, hepatomegaly, splenomegaly, and central nervous system dysfunction
• Diagnosis: H&P, CBC with peripheral blood smear, and bone marrow biopsy
• Treatment: chemotherapy and bone marrow transplant

Chronic Myeloid Leukemia

• Affects primarily adults
• Responds poorly to chemotherapy, but prognosis is improved with allogenic bone marrow transplant

Acute Lymphocytic Leukemia

• Affects young children
• Best prognosis is found in children between 1 and 9 years of age; infants and adolescents respond less positively to chemotherapy

Acute Myelogenous Leukemia

• Affects adults
• Chemotherapy is less successful in adults with AML, although remissions may be achieved

Chronic Lymphocytic Leukemia

• Affects adults >50 years
• Prognosis is often related to the WBC count and the proportion of blast cells present at the time of diagnosis

Hairy Cell Leukemia

• Affects males >50 years

Hemoglobin Structure

• Globin group: surrounded by the four heme groups
• Heme groups: ring-like organic compounds called porphyrins with an iron atom attached
• Protein chains: two alpha chains and two beta chains, each with a heme group