A 49-year-old female is admitted to hospital due to shortness of breath and pleuritic chest pain. She also complains of a marked decrease in appetite for the past 4 months. An admission chest x-ray shows a right-sided pleural effusion. An underlying malignancy is suspected and a series of tumour markers are requested:
What is the most likely underlying diagnosis?
Correct Answer A: This patient has Meig's syndrome - an ovarian fibroma associated with a pleural effusion and ascites.
Tumour markers:
Tumour markers may be divided into:
It should be noted that tumour markers usually have a low specificity.
Monoclonal antibodies:
Tumour antigens:
A 12-year-old boy is noted to bleed excessively during an elective dental extraction. Following the procedure, examination reveals petechial skin haemorrhages. Blood results show:
What is the most likely diagnosis?
Correct Answer C: The combination of a petechial skin rash combined with a slightly elevated APTT and reduced factor VIII activity make Von Willebrand's disease the most likely diagnosis.
Von Willebrand's disease: Von Willebrand's disease is the most common inherited bleeding disorder. The majority of cases are inherited in an autosomal dominant fashion* and characteristically behaves like a platelet disorder i.e. epistaxis and menorrhagia are common whilst haemoarthroses and muscle haematomas are rare.
Role of von Willebrand factor:
Types:
Investigation:
Management:
*Type 3 von Willebrand's disease (most severe form) is inherited as an autosomal recessive trait. Around 80% of patients have type 1 disease
A 52-year-old woman with a history of hypothyroidism presents with lethargy and a sore tongue. Blood tests are reported as follows:
Further tests are ordered:
What is the most appropriate management?
Correct Answer B: If the patient was deficient in folic acid it would important to treat the B12 deficiency first to avoid precipitating subacute combined degeneration of the cord.
Vitamin B12 deficiency:
Vitamin B12 is mainly used in the body for red blood cell development and also maintenance of the nervous system. It is absorbed after binding to intrinsic factor (secreted from parietal cells in the stomach) and is actively absorbed in the terminal ileum. A small amount of vitamin B12 is passively absorbed without being bound to intrinsic factor.
Causes of vitamin B12 deficiency:
Features of vitamin B12 deficiency:
A 54-year-old man is diagnosed as having acute myeloid leukaemia.
What is the single most important test in determining his prognosis?
Correct Answer E: All of the above may be important but chromosomal abnormalities detected by cytogenetics are the single most important prognostic factor.
Acute myeloid leukaemia: Acute myeloid leukaemia is the more common form of acute leukaemia in adults. It may occur as a primary disease or following a secondary transformation of a myeloproliferative disorder.
Poor prognostic features:
Acute promyelocytic leukaemia M3:
Classification - French-American-British (FAB):
A patient with a history of recurrent thromboembolic events develops a deep vein thrombosis despite full anticoagulation with heparin.
Which one of the following causes of thrombophilia is associated with resistance to heparin?
Correct Answer B: Heparin works by binding to antithrombin III, enhancing its anticoagulant effect by inhibiting the formation of thrombin and other clotting factors. Patients with antithrombin III deficiency may therefore by resistant to heparin treatment.
Antithrombin III deficiency:
Antithrombin III deficiency is an inherited cause of thrombophilia occurring in approximately 1:2,000 of the population. Inheritance is autosomal dominant Antithrombin III inhibits several clotting factors, primarily thrombin, factor X and factor IX. It mediates the effects of heparin.
Antithrombin III deficiency comprises a heterogeneous group of disorders, with some patients having a deficiency of normal antithrombin III whilst others produce abnormal antithrombin III.
Features:
*As patients with antithrombin III deficiency have a degree of resistance to heparin anti-Xa levels should be monitored carefully to ensure adequate anticoagulation.
Click to expand