Answers to case study questions
Case Study 5.1 We ﬁnd a 50-year-old woman with long-term Crohn’s disease, on various treatments and with an abdominal surgical history. Her blood tests were requested following a routine GP visit, when she complained of some lethargy, fever and diarrhoea. (p. 125) 1 The results outside the reference range are haemoglobin, MCV and ESR. This result, along with the history, is sufficient to confer the diagnosis of anaemia. With the MCV below the bottom of the reference range, we can extend the diagnosis to microcytic anaemia. The abnormal ESR adds little to the diagnosis as it is the likely consequence of the anaemia. 2 Having given the ...view middle of the document...
On examination, there is a swollen and painful tongue, and she complains of becoming forgetful, with occasional ‘tingling’ of her ﬁngertips and numbness in her toes. (p. 135) 1 Results outside the reference range are haemoglobin, MCV and ESR. This result, along with the history, is sufficient to confer the diagnosis of anaemia. With the MCV above the top of the reference range, we can extend the diagnosis to macrocytic anaemia. The abnormal ESR adds little to the diagnosis as it is the likely consequence of the anaemia. 2 The key result is the low serum vitamin B12, which provides the most likely cause of the disease and symptoms. Indeed, the symptoms are typical. Normal iron levels seem likely to count against malnutrition. One could proceed to determine the precise cause of the deﬁciency, which, if found to be autoantibodies to gastric parietal cells or IF, will confer the diagnosis of pernicious anaemia. In most clear cases (such as this), examination of the bone marrow (to search for megaloblasts) seems unnecessary. 3 The next step will be treatment with parenteral vitamin B12, with monitoring after several weeks to conﬁrm its effect on the full blood count. Case Study 5.3 An 82-year-old man complains of being tired and lethargic. On examination, he is pale and there is a distended and painful abdomen. He also complains of periodic diarrhoea and constipation and recalls that he has lost perhaps a stone in the past year. (p. 139) 1 The abnormalities are low haemoglobin and raised ESR. This, coupled with the history (being pale and complaining of tiredness and lethargy) is sufficient to give a diagnosis of anaemia. With an MCV within the normal range, we describe a normocytic anaemia. 2 If the anaemia is normocytic then we are likely, at this stage, to eliminate failure to provide micronutrients to the bone marrow. It is also unlikely that there is a haemoproliferative disease within the bone marrow (such as leukaemia) as the white blood cell count and platelet count are both within the reference range. This, however, still leaves numerous possible reasons, such as haemolysis, and other tests could be used to exclude some diagnoses, such as a direct or indirect antiglobulin test for autoimmune or other antibody-mediated haemolytic anaemia. 3 In many cases, non-laboratory information can be useful, and the history can provide clues. There is loss of weight over a year, and gastrointestinal symptoms. This is indicative of several possible diagnoses, bowel malignancy among them. If this is the cause of the anaemia, one mechanism may be loss of blood into the faeces, which would normally be undetectable. This can be tested with the test ‘faecal occult blood’.
Case Study 6.1 In case study 1 (p. 176), the patient is a young woman from the Far East with a history of tiredness and lethargy but few other symptoms of note. Abnormalities include a low haemoglobin, MCH,...