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ANSWER 55

The likely diagnosis is achalasia of the cardia, a primary neurological disturbance of the nerve plexuses at the lower end of the oesophagus. The X-ray shows a dilated fluid-filled oesophagus with no visible gastric air bubble. Endoscopy may be normal in the early stages as in this case. The oesophagus has now dilated and there has been spill-over of stagnant food into the lungs giving her the episodes of repeated respiratory infections. Such aspiration is most likely to affect the right lower lobe because of the more vertical right main bronchus, although the result of aspiration at night may depend on the position of the patient. The dysphagia is often variable early on. It tends to be present for all foods, indicating a motility problem, and there may initially be some relief from the mechanical load as the oesophagus fills. Dysphagia for bulky, solid foods first usually indicates an obstructive lesion.

The diagnosis can be made at this stage by a barium swallow showing the dilated oesophagus. Earlier it may require careful cine-radiology with a bolus of food impregnated with barium, or oesophageal motility studies using a catheter fitted with a number of pressure sensors to detect the abnormal motility of the oesophageal muscle.

A similar condition can be produced by the protozoan parasite Trypanosoma cruzi (Chagas’ disease), but this is limited to South and Central America and would not be relevant to her stay in the north-west United States.

Other common causes of dysphagia are benign oesophageal structures from acid reflux, malignant structures, external compression or an oesophageal pouch. Achalasia may be managed by muscle relaxants when mild, but often requires treatment to disrupt the lower oesophageal muscle by dilatation or surgery.

KEY POINTS

•The subjective site of blockage in dysphagia may not reflect accurately the level of the obstruction.

•Persistent dysphagia without explanation needs investigation by barium swallow or endoscopy.

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CASE 56: GENERALIZED ITCHING

History

A 63-year-old man presents to his general practitioner (GP) complaining that over the past 3 months he has developed severe generalized itching. This is particularly severe after a hot bath. He has also noticed frequent headaches, dizziness and tinnitus. He has been hypertensive for 10 years. He smokes 35 cigarettes a day and drinks about 25 units of alcohol per week. He takes bendroflumethiazide for his hypertension. He works as a chef, is divorced and lives alone.

Examination

His face looks plethoric. He has no rash. There are no signs of chronic liver disease and no lymphadenopathy. His pulse is 84/min regular and blood pressure 162/104 mmHg. Examination of his heart and respiratory system is normal. In his abdomen the only abnormality is that his spleen is palpable 4 cm below the left costal margin. Neurological examination is normal.

INVESTIGATIONS

Questions

•What is the likely diagnosis?

•What are the major causes of generalized itching without a rash?

•How would you investigate and manage this patient?

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ANSWER 56

This patient has polycythaemia rubra vera. This is due to abnormal proliferation of red cell precursors derived from a single haematopoietic progenitor cell with the capacity for differentiation down red cell, white cell and platelet lines. As a result, there is an increase in haemoglobin, white cell count and platelet level. Patients may present with a thrombotic event or with symptoms due to increased blood viscosity such as headaches, tinnitus and blurred vision. There is an increased bleeding tendency. Splenomegaly is common. Severe pruritus is characteristic and is particularly related to warmth occurring on getting into a warm bed or bath.

!Conditions associated with generalized pruritus without a rash

•Obstructive jaundice due to bile salt retention

•Iron deficiency

•Lymphoma

•Carcinoma, especially bronchial

•Chronic renal failure, partially due to phosphate retention

This patient should be referred to a haematology unit for investigation. It is important to exclude relative polycythaemia due to dehydration from diuretic and alcohol use. The red cell mass will be raised in polcythaemia rubra vera, but normal in relative polycythaemia. The following causes of secondary polycythaemia must be excluded:

•chronic lung disease with hypoxia

•cyanotic congenital heart disease

•renal cysts, tumours, renal transplants

•hepatoma, cerebellar haemangioblastoma, uterine fibroids

•Cushing’s disease.

The erythropoietin level is low in polycythaemia rubra vera and high in secondary polycythaemia. Pulse oximetry or arterial blood gases should be performed to exclude hypoxia. The leucocyte alkaline phosphatase level is also raised in polycythaemia rubra vera.

The patient should be venesected until the haematocrit is within the normal range. A variety of agents can be used to keep the haematocrit down: 32P, hydroxyurea and busulphan. The disease may transform into acute leukaemia or myelosclerosis.

KEY POINTS

• Severe generalized pruritus is a characteristic symptom of polycythaemia rubra vera.

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CASE 57: COUGH AND JOINT PAINS

History

A 29-year-old man presents with a cough and some mild aches in the hands, wrists and ankles. The symptoms have been present for 2 months and have increased slightly over that time. Six weeks before he had some soreness of his eyes, which resolved in 1 week.

The cough has been non-productive. He had noticed some skin lesions on the edge of the hairline and around his nostrils. Previously he had been well apart from an appendicectomy at the age of 17 years.

He was born in Trinidad and came to the UK at the age of 4 years. His two brothers and parents are well. He does not smoke, is teetotal and takes no recreational drugs. He works as a messenger and took regular exercise until the last few weeks.

Examination

There is no deformity of the joints and no evidence of any acute inflammation. In the respiratory and cardiovascular system there are no abnormal findings. In the skin there are some slightly raised areas on the edge of the hairline posteriorly and at the ala nasae. They are a little lighter than the rest of the skin.

INVESTIGATIONS

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Figure 57.1 Chest X-ray.

Questions

•What is the likely diagnosis?

•How might this be confirmed?

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ANSWER 57

The likely diagnosis is sarcoidosis. The age is typical and sarcoidosis is more common in those of African-Caribbean origin. The chest X-ray shows bilateral hilar lymphadenopathy. The blood results show a slightly raised calcium level which is related to vitamin D sensitivity in sarcoidosis where the granulomas hydroxylate 25-hydroxycholecalciferol to 1,25dihydroxycholecalciferol. The ESR is raised and some of the liver enzymes are around the upper limit of normal. The skin lesions at the hairline and the nostrils are typical sites for sarcoid skin problems. The eye trouble 6 weeks earlier might also have been a manifestation of sarcoidosis, which can cause both anterior and posterior uveitis.

An alternative diagnosis which might explain the findings is tuberculosis. Tuberculosis can also cause hypercalcaemia although this is much less common than in sarcoid. Tumours, especially lymphoma, might give this X-ray appearance but would not explain the other findings. The arthralgia (pains with no evidence of acute inflammation or deformity on examination) can occur in sarcoid or tuberculosis but again they are commoner in sarcoid. The ESR is non-specific. Arthralgia without deformity in an African-Caribbean man raises the possibility of systemic lupus erythematosus (SLE), but this would be much commoner in women and would not cause bilateral hilar lymphadenopathy.

He is likely to have had BCG (bacille Calmette–Guèrin) vaccination at school at around the age of 12 years, giving a degree of protection against tuberculosis. A tuberculin test should be positive after BCG, strongly positive in most cases of tuberculosis and negative in 80 per cent of cases of sarcoidosis. The serum level of angiotensin-converting enzyme would be raised in over 80 per cent of cases of sarcoidosis but often in tuberculosis also; the granuloma cells secrete this enzyme. A computed tomography (CT) scan of the chest will confirm the extent of the lymphadenopathy and show whether there is any involvement of the lung parenchyma. Histology of affected tissue would confirm the clinical diagnosis. This might be obtained by a skin biopsy of one of the lesions. A bronchial or transbronchial lung biopsy at fibreoptic bronchoscopy would be another means of obtaining diagnostic histology. In patients with a cough and sarcoidosis the bronchial mucosa itself often looks abnormal, and biopsy will provide the diagnosis. Lung function tests and electrocardiogram (ECG) should be performed as a baseline if the diagnosis is confirmed.

Steroid treatment would not be necessary for the hilar lymphadenopathy alone, but would be indicated for the hypercalcaemia and possibly for the systemic symptoms.

KEY POINTS

•Sarcoidosis is commoner in African-Caribbeans.

•Typical sites for skin lesions are around the nose and the hairline.

•Sarcoidosis is a systemic disease and can affect most parts of the body.

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CASE 58: THIRST AND FREQUENCY

History

A 63-year-old woman is referred to a nephrologist for investigation of polyuria. About 4 weeks ago she developed abrupt-onset extreme thirst and polyuria. She is getting up to pass urine five times a night. Over the past 3 months she has felt generally unwell and noted pain in her back. She has lost 3 kg in weight over this time. She also has a persistent frontal headache associated with early morning nausea. The headache is worsened by coughing or lying down. Eight years previously she had a left mastectomy and radiotherapy for carcinoma of the breast. She is a retired civil servant who is a non-smoker and drinks 10 units of alcohol per week. She is on no medication.

Examination

She is thin and her muscles are wasted. Her pulse rate is 72/min, blood pressure 120/84 mmHg, jugular venous pressure is not raised, heart sounds are normal and she has no peripheral oedema. Examination of her respiratory, abdominal and neurological systems is normal. Her fundi show papilloedema.

INVESTIGATIONS

Questions

•What is the likely cause of her polyuria?

•How would you investigate and manage this patient?

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ANSWER 58

This woman has mild hypercalcaemia but this is not high enough to explain her extreme thirst and polyuria. It is more likely that she has polyuria due to neurogenic diabetes insipidus as a result of secondary metastases in her hypothalamus. The hypercalcaemia and raised alkaline phosphatase are suggestive of bony metastases secondary to her breast carcinoma. The recent-onset headache, worsened by coughing and lying down and associated with vomiting is characteristic of raised intracranial pressure, which is confirmed by the presence of papilloedema. In some tumours around the pituitary there may be compression of the optic nerve causing visual field abnormalities. Neurogenic diabetes insipidus is due to inadequate arginine vasopressin (AVP, antidiuretic hormone) secretion. About 30 per cent of cases of neurogenic diabetes insipidus are idiopathic. The remaining causes are neoplastic, infectious, inflammatory (granulomas), traumatic (neurosurgery, deceleration injury) or vascular (cerebral haemorrhage, infarction). Patients with central diabetes insipidus typically describe an abrupt onset of polyuria and polydipsia. This is because urinary concentration can be maintained fairly well until the number of AVP-secreting neurones in the hypothalamus decreases to 10–15 per cent of the normal number, after which AVP levels decrease to a range where urine output increases dramatically.

!Major causes of polyuria and polydipsia

•Solute diuresis, e.g. diabetes mellitus.

•Renal diseases which impair urinary concentrating mechanisms, e.g. chronic renal failure.

•Drinking abnormalities: psychogenic polydipsia.

•Renal resistance to the action of AVP.

•Nephrogenic diabetes insipidus (due to inherited defects either in the AVP V2 receptor or the aquaporin-2 receptor)

•Hypokalaemia

•Hypercalcaemia

•Drugs, e.g. lithium, demeclocycline.

A water-deprivation test should be performed in this patient, measuring the plasma sodium, urine volume and urine osmolality until the sodium rises above 146 mmol/L, or the urine osmolality reaches a plateau and the patient has lost at least 2 per cent of body weight. At this point AVP is measured, and the response to subcutaneous desmopressin is measured. An increase in urine osmolality #50 per cent indicates central diabetes insipidus and !10 per cent nephrogenic diabetes insipidus. The hypothalamus should be imaged by magnetic resonance imaging (MRI) scanning and bone X-rays and bone scans performed to identify metastases (Fig. 58.1). The MRI scan (T1-weighted coronal image) through the pituitary in Fig. 58.1 shows thickening of the pituitary stalk due to metastatic disease (short arrow) and partial replacement of the normal bone marrow of the clivus by metastatic tumour (long arrow). Treatment of the neurogenic diabetes insipidus involves regular intranasal DDAVP (L-deamino-8-D-arginine vasopressin). She should be referred to an oncologist for treatment of her metastatic carcinoma.

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Figure 58.1 Magnetic resonance imaging scan through the pituitary.

KEY POINTS

•The commonest causes of polyuria are diabetes mellitus and chronic renal failure.

•Breast carcinoma may recur after several years of remission.

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