Материал: 100_Cases_in_Clinical_Medicine
ANSWER 43
The symptoms she describes raise the possibility of a 5-hydroxytryptamine (5-HT)-secreting carcinoid tumour. The typical clinical features of the carcinoid syndrome are facial flushing, abdominal cramps and diarrhoea. Sometimes there is asthma and right-sided heart valve problems. The symptoms are characteristically intermittent and may come at times of increased release on activity. Skin changes may be persistent.
The CT scan of the liver shows a space-occupying lesion in the liver likely to represent a metastasis to the liver. Fluid-containing cystic lesions are of lower density. Other secondary tumours would give a similar appearance. Carcinoids do not generally produce their symptoms until they have metastasized to the liver from their original site, which is usually in the small bowel. In the small bowel the tumours may produce local symptoms of obstruction or bleeding.
The symptoms of carcinoid tumours are related to the secretion of 5-HT by the tumour. The diagnosis depends on finding a high level of the metabolite 5-hydroxyindole acetic acid (5-HIAA) in a 24-h collection of urine. Histology can be obtained from a liver biopsy guided to the correct area by ultrasound or CT.
The symptoms can be controlled by antagonists of 5-HT such as cyproheptadine or by inhibitors of its synthesis p-chlorophenylalanine, or release, octreotide. The tumour can be reduced in size with consequent lessening of symptoms by embolization of its arterial supply using interventional radiology techniques.
When odd symptoms such as those described here occur, the diagnosis of carcinoid tumour should always be remembered and investigated. In real life, most of the investigations for suspected carcinoid turn out to be negative.
Carcinoid tumours can occur in the lung when they act as slowly growing malignant tumours. From the lung they can eventually be associated with left heart-valve problems. The other typical carcinoid features occur only after metastasis to the liver.
KEY POINTS
•Intermittent skin flushing, diarrhoea, wheezing and abdominal cramps are symptoms of the carcinoid syndrome.
•All these symptoms have much commoner causes.
•Metastasis to the liver is present before the symptoms of carcinoid syndrome occur.
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CASE 44: UNCONSCIOUS AT HOME
History
A 28-year-old woman is admitted to the emergency department in a coma. The patient was found unconscious on the floor by her boyfriend. She had not been seen by anyone for the previous 48 h. No history was available from the patient, but her partner volunteered the information that they are both intravenous heroin addicts. She is unemployed, smokes 25 cigarettes per day, drinks 40 units of alcohol per week and has used heroin for the past 4 years. They have occasionally shared needles with other addicts. They both had negative HIV tests about 1 year ago. She has not made any suicide attempts in the past. She has had no other medical illnesses. She has lost touch with her family.
Examination
There are multiple old scarred needle puncture sites. Her pulse is 64/min regular, blood pressure 110/60 mmHg, jugular venous pressure not raised, heart sounds normal. Her respiratory rate is 12/min, and she has dullness to percussion and bronchial breathing at the left base posteriorly. Abdominal examination is normal. Her conscious level is depressed but she is rousable to painful stimuli. She has pinpoint pupils, but has no focal neurological signs. A bolus injection of intravenous naloxone causes her conscious level to rise transiently. Her left arm is swollen and painful from the shoulder down.
INVESTIGATIONS
|
|
Normal |
Haemoglobin |
13.6 g/dL |
13.3–17.7 g/dL |
White cell count |
9.2 % 109/L |
3.9–10.6 % 109/L |
Platelets |
233 % 109/L |
150–440 % 109/L |
Sodium |
137 mmol/L |
135–145 mmol/L |
Potassium |
7.8 mmol/L |
3.5–5.0 mmol/L |
Urea |
42.3 mmol/L |
2.5–6.7 mmol/L |
Creatinine |
622 &mol/L |
70–120 &mol/L |
Bicarbonate |
14 mmol/L |
24–30 mmol/L |
Glucose |
4.1 mmol/L |
4.0–6.0 mmol/L |
Calcium |
1.64 mmol/L |
2.12–2.65 mmol/L |
Phosphate |
3.6 mmol/L |
0.8–1.45 mmol/L |
Creatine kinase |
68 000 IU/L |
25–195 IU/L |
Arterial blood gases on air |
|
|
pH |
7.27 |
7.38–7.44 |
pCO2 |
7.5 kPa |
4.7–6.0 kPa |
pO2 |
9.2 kPa |
12.0–14.5 kPa |
Urinalysis: ' protein; ''' blood |
|
|
Urine microscopy: brown urine; no red cells; many granular casts
Electrocardiogram (ECG): flattened P-wave; peaked T-waves
Chest X-ray: extensive left-lower-zone consolidation
Questions
•What is the cause of this patient’s acute renal failure?
•What further immediate and longer treatment does this woman need?
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ANSWER 44
This patient has acute renal failure as a result of rhabdomyolysis. Severe muscle damage causes a massively elevated serum creatine kinase level, and a rise in serum potassium and phosphate levels. In this case, she has lain unconscious on her left arm for many hours due to an overdose of alcohol and intravenous heroin. As a result, she has developed severe ischaemic muscle damage causing release of myoglobin which is toxic to the kidneys.
Other causes of rhabdomyolysis include crush injuries, severe hypokalaemia, excessive exercise, myopathies, drugs (e.g. ciclosporin and statins) and certain viral infections. The urine is dark because of the presence of myoglobin which causes a false-positive dipstick test for blood. Acute renal failure due to rhabdomyolysis causes profound hypocalcaemia in the oliguric phase due to calcium sequestration in muscle, and reduced 1,25-dihydroxycalciferol levels, often with rebound hypercalcaemia in the recovery phase. This woman’s conscious level is still depressed as a result of opiate and alcohol toxicity and she has clinical and radiological evidence of an aspiration pneumonia. She has a mixed metabolic and respiratory acidosis (low pH, bicarbonate) due to acute renal failure and respiratory depression (pCO2 elevated). Her arterial oxygenation is reduced due to hypoventilation and pneumonia. She also has a compartment syndrome in her arm due to massive swelling of her damaged muscles.
This patient has life-threatening hyperkalaemia with electrocardiogram (ECG) changes. The ECG changes of hyperkalaemia progress from the earliest signs of peaking of the T-wave, P-wave flattening, prolongation of the PR interval through to widening of the QRS complex, a sine-wave pattern and ventricular fibrillation. Emergency treatment involves intravenous calcium gluconate which stabilizes cardiac conduction, and intravenous insulin/glucose, intravenous sodium bicarbonate and nebulized salbutamol, all of which temporarily lower the plasma potassium by increasing the cellular uptake of potassium. However, these steps should be regarded as holding measures while urgent dialysis is being organized.
The chest X-ray and clinical findings indicate consolidation of the left lower lobe. This patient should initially be managed on an intensive care unit. She will require antibiotics for her pneumonia and will require a naloxone infusion or mechanical ventilation for her respiratory failure. The patient should have vigorous rehydration with monitoring of her central venous pressure. If a good urinary flow can be maintained, urinary pH should be kept at !7.0 by bicarbonate infusion which prevents the renal toxicity of myoglobin. This patient also needs to be considered urgently for surgical fasciotomy to relieve the compartment syndrome in her arm.
In the longer term, the patient needs counselling and with her boyfriend should be offered access to drug-rehabilitation services. They should also be offered testing for blood-borne viruses (hepatitis B and C and HIV).
KEY POINTS
•Acute hyperkalaemia is a life-threatening emergency.
•A very high creatine kinase level is diagnostic of rhabdomyolysis.
•As statins are now so widely used, they have become a common cause of rhabdomyolysis, especially when used in high dose and in combination with ciclosporin.
•Aggressive fluid replacement and a forced alkaline diuresis can prevent renal damage in rhabdomyolysis if started early enough.
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CASE 45: EXCESS HAIR GROWTH
History
A 22-year-old woman is referred to a dermatologist complaining of increasing growth of hair affecting her face. This has progressed over at least 2 years so that now she needs to shave to remove her facial hair. She has also noticed facial acne and that her skin is more greasy. Her periods have become very irregular with her last period being 3 months previously. Her menarche was at age 13 years, but over the past 3 years her periods have been very erratic with her intermenstrual interval ranging from a few days to many months and her blood loss varying from light to heavy. She has had no significant medical illnesses previously. She is taking no regular medication. She lives alone, smokes 20 cigarettes per week and drinks about 20 units of alcohol per week. She is a student but has stopped attending her course because she is embarassed by her appearance.
Examination
She is overweight at 16 stone. Her facial skin is greasy and she has excessive facial hair. Blood pressure is 132/82 mmHg, pulse 76/min. Physical examination is otherwise normal.
INVESTIGATIONS
|
|
Normal |
Follicle-stimulating hormone (FSH) |
1 U/L |
2–8 U/L |
Luteinizing hormone (LH) |
32 U/L |
6–13 U/L |
Oestradiol |
284 nmol/24 h |
10–55 nmol/L |
Testosterone |
9.6 nmol/L |
1–2.1 nmol/L |
Questions
•What is the diagnosis?
•How would you investigate and manage this patient?
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ANSWER 45
This patient has hirsutism and secondary amenorrhoea due to polycystic ovaries (Stein– Leventhal syndrome). This is a complex disorder characterized by excessive androgen production by the ovaries and/or adrenal cortex which interferes with ovarian follicular ripening. Patients are usually obese with the adipose tissue converting androgens to oestrogens, leading to high LH levels stimulated by positive feedback of oestrogens on the pituitary, and low FSH levels due to negative feedback. The low FSH level means that ovarian follicles do not mature normally. A large number of follicles develop abnormally leading to enlarged ovaries.
!Differential diagnoses of hirsutism
•Constitutional
•Drugs, e.g. ciclosporin, minoxidil
•Cushing’s syndrome
•Congenital adrenal hyperplasia
•Androgen-secreting tumours
•Hypothyroidism
Patients with androgenic tumours usually have a shorter history, signs of virilism such as clitoral hypertrophy and very high testosterone levels. This woman had an ovarian ultrasound (Fig. 45.1) which showed polycystic ovaries. A laparoscopic biopsy confirmed the diagnosis. Hirsutism can be treated by combined oestrogen/progestogen oral contraception (to induce sex hormone-binding globulin and thus mop up excess unbound testosterone) and by the anti-androgen, cyproterone acetate. Ovulation can be induced with clomifene or pulsatile gondotrophin-releasing hormone (GnRH) therapy. Dietary advice should be given to reduce obesity which otherwise helps maintain the condition. She will need social and psychological support to return to her studies and social life.
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