Hematology

Ref: Davidson 23rd; P- 938

Explanation: coagulation screening tests are Platelet count, PT, APTT & Fibrinogen concentration

Explanation: DNA replication occurs in S(synthesis) phase of cell cycle

Ref: Davidson 23rd; P-928, box: 23.13

Ref: Davidson 23rd; P- 959

Ref: Davidson 23rd; P- 941

Answer: C
Explanation: Chronic blood loss, particularly from the gastrointestinal tract or menstruation, is the most common cause of iron deficiency anaemia worldwide. Davidson highlights that iron deficiency leads to decreased haemoglobin synthesis and microcytic, hypochromic anaemia. Harrison further emphasises that iron deficiency is more prevalent in low-income countries due to dietary insufficiency and parasitic infections.

Explanation: Iron deficiency anaemia is the most common type of anaemia worldwide. A thorough gastrointestinal history is important, looking in particular for symptoms of blood loss. Menorrhagia is a common cause of anaemia in pre-menopausal females, so women should always be asked about their periods

Haemorrhagic disease of the newborn: Haemorrhagic disease of the newborn: enzyme-inducing antiepileptic drugs increase risk. Give IM vitamin K (1 mg) to the infant at birth.

Painless lymphadenopathy, especially in the cervical or supraclavicular regions, is the most common presenting symptom of Hodgkin lymphoma. Davidson describes that patients may also experience systemic "B symptoms" such as fever, night sweats, and weight loss. Harrison adds that Hodgkin lymphoma often spreads in a predictable pattern from one lymph node group to another, and the presence of Reed-Sternberg cells on biopsy is diagnostic.

Explanation: Monocyte & Lymphocytes are agranulocytic white blood cell.

Explanation: Factor VIII deficiency resulting in haemophilia A affects 1/10 000 individuals. It is the most common congenital coagulation factor deficiency

Stem Breakdown:

Back pain, fatigue, and recurrent infections: These symptoms suggest multiple myeloma, a plasma cell malignancy that causes bone pain, anemia, and immunodeficiency.
Hypercalcemia and anemia: Hypercalcemia is due to bone destruction (osteolytic lesions), and anemia results from bone marrow infiltration by malignant plasma cells.
Elevated serum protein levels and rouleaux formation: These findings suggest excess monoclonal proteins (M-protein) in the blood, which is characteristic of multiple myeloma.
Option Analysis:

A) Multiple myeloma: This is the correct diagnosis. Davidson and Harrison describe multiple myeloma as a malignancy of plasma cells, leading to bone destruction, anemia, hypercalcemia, renal dysfunction, and immunodeficiency. Rouleaux formation on a blood smear is due to high levels of circulating monoclonal proteins, which interfere with red blood cell separation.
B) Chronic lymphocytic leukemia (CLL): CLL is a malignancy of B lymphocytes and causes lymphadenopathy, fatigue, and increased susceptibility to infections. However, it does not cause hypercalcemia or rouleaux formation.
C) Waldenström’s macroglobulinemia: This condition is associated with the production of IgM monoclonal protein, which can cause hyperviscosity symptoms but does not typically cause bone pain, hypercalcemia, or rouleaux formation.
D) Hyperparathyroidism: Hyperparathyroidism causes hypercalcemia due to overproduction of parathyroid hormone, but it does not cause anemia, rouleaux formation, or elevated serum protein levels.

Ref: Davidson 23rd; P-946, box: 23.36

Ref: Davidson 23rd; P- 924 (Fig-23.10)

Ref: Davidson 23rd; P-954, box - 23.40

Ref: Davidson 23rd; P-949 (Box-23.38)

Variations in red cell size is called anisocytosis.

Stem Breakdown:

Fatigue, weight loss, and night sweats: These are "B symptoms," often seen in lymphomas.
Enlarged, non-tender lymph nodes in the cervical and axillary regions: Painless lymphadenopathy is a common presenting sign of lymphoma.
Option Analysis:

A) Hodgkin lymphoma: Hodgkin lymphoma typically presents with painless lymphadenopathy and "B symptoms," but it is more likely to involve mediastinal lymph nodes rather than widespread cervical and axillary nodes. The presence of Reed-Sternberg cells on biopsy confirms the diagnosis, but the stem lacks specific findings for Hodgkin lymphoma.
B) Non-Hodgkin lymphoma: This is the correct diagnosis. Davidson and Harrison explain that non-Hodgkin lymphoma (NHL) often presents with painless, generalized lymphadenopathy and systemic symptoms like weight loss and night sweats. NHL is more likely than Hodgkin lymphoma to cause widespread lymph node involvement.
C) Chronic lymphocytic leukemia (CLL): CLL causes painless lymphadenopathy and systemic symptoms, but it is also associated with an elevated white blood cell count (lymphocytosis), which is not mentioned in the case.
D) Tuberculosis: Tuberculosis can cause lymphadenopathy, particularly in the cervical region (scrofula), and systemic symptoms, but it typically presents with caseating granulomas on biopsy, and pulmonary involvement is common.

Ref: Davidson 23rd; P- 921(Box-23.2)

Explanation: IgG distributed equally between blood and extracellular fluid and transported across placenta.

Reference: Davidson 23rd, Fig-23.17

Stem Breakdown:

Fatigue, pallor, and heavy menstrual periods: These symptoms suggest anaemia, and the history of heavy periods (menorrhagia) suggests blood loss as a likely cause.
Haemoglobin of 8.5 g/dL and MCV of 70 fL: The low haemoglobin indicates anaemia, and the low MCV (microcytosis) is characteristic of iron deficiency anaemia.
Option Analysis:

A) Iron deficiency anaemia: This is the correct diagnosis. Davidson and Harrison explain that iron deficiency anaemia is the most common cause of anaemia worldwide and is often due to chronic blood loss, particularly from menstruation in women. The microcytic, hypochromic anaemia (low MCV) is a hallmark finding.
B) Vitamin B12 deficiency: Vitamin B12 deficiency causes macrocytic anaemia (high MCV), not microcytic anaemia. Symptoms include neurological deficits, such as paraesthesia and balance problems, which are absent in this case.
C) Aplastic anaemia: Aplastic anaemia presents with pancytopenia (low red cells, white cells, and platelets) and a hypocellular bone marrow. It does not cause microcytosis and is not related to blood loss from menstruation.
D) Haemolytic anaemia: Haemolytic anaemia causes normocytic or macrocytic anaemia with increased reticulocytes and evidence of haemolysis (e.g., elevated bilirubin, LDH). There is no evidence of haemolysis in this case, and the low MCV points to iron deficiency.

Reference: Davidson 23rd, Box-3.4

Explanation: Factor V Leiden mutation is the most common inherited thrombophilia. Davidson explains that this mutation renders Factor V resistant to inactivation by activated protein C, leading to a prothrombotic state. Harrison discusses that individuals with Factor V Leiden have a higher risk of venous thromboembolism, particularly in the presence of additional risk factors like surgery or immobility.

Explanation: Iron deficiency anaemia is the most common type of anaemia worldwide.

Reference: Davidson 23rd, Box-23.17

Explanation: Humoral immunity is mediated by B lymphocytes, which differentiate from haematopoietic stem cells in the bone marrow.

Acute cellular rejection is the most common form of graft rejection.

Reference: Davidson 23rd; P-137

Hepatitis B and C testing. This should be done prior to therapy with rituximab in NHL

Ref: Davidson 23rd; P-944, box: 23.32

Reference: Davidson 23rd, Box-3.4

Ref: Davidson 23rd; P-971

TP is characterised by a pentad of findndings, although few patients have all five components:
 thrombocytopenia  microangiopathic haemolytic anaemia  neurological sequelae  fever  renal impairmen

CLL is caused by a monoclonal proliferation of B-cell lymphocytes