Sunday, January 13, 2008

9 - surgery mcqs - 51 to 60

51. The following are features of Cushing's syndrome

(a) Hypotension
(b) Increased sodium excretion
(c) A proximal myopathy
(d) Thin skin with purple striae
(e) A buffalo hump

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c , d , e are right . Cushing's syndrome results from glucocorticoid excess. At high levels cortisol also has mineralocortoid activity that results in both sodium and water retention. This can result in hypertension. Increased protein catabolism results in muscle weakness, skin thining and increased bruising. Osteoporosis can result in a kyphosis and typical buffalo hump.

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52. Regarding carcinoid tumours

(a) The appendix is the commonest primary site for gastrointestinal tumours
(b) Gastric carcinoid tumours produce little 5-hydroxyindoleacetic acid
(c) Liver metastases can result in the carcinoid syndrome
(d) Plasma chromogranin B may be increased
(e) Octreotide scintigraphy may identify both the primary and secondary lesions

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a , b , c , e are right . The appendix is the commonest site of gastrointestinal carcinoid tumours. Midgut and hindgut tumours secrete 5HIAA but little is produced by foregut tumours. Plasma chromogranin A is increased. Octreotide is a somatostatin analogue. Radiolabelled octreotide can be used to identify the site of primary and secondary tumours.

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53. Hashimoto's thyroiditis

(a) Is an acute suppurative disease due to a bacterial infection
(b) Often presents has a solitary thyroid nodule
(c) Is a common cause of hyperthyroidism
(d) Anti-thyroglobulin and anti-microsomal antibodies may be increased
(e) Increases the risk of thyroid lymphoma

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d , e are right . Hashimoto's thyroiditis is an autoimmune disease. It usually presents as a diffuse goitre and long-term can cause hypothyroidism. Anti-thyroglobulin and anti-microsomal antibodies are increased. The disease predisposes to thyroid lymphoma.

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54. Thoracic outlet syndrome

(a) Is more common in men than women
(b) Vascular symptoms are more common than neurological or venous symptoms
(c) Symptoms are often worsened by carrying weights or lifting the arms above head height
(d) Diagnostic tests include the Roo's and Adson's manoeuvre
(e) Onset of symptoms is precipitated by trauma in about one-third of patients

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c , d , e are right answers . Thoracic outlet syndrome results from compression of the subclavian artery, subclavian vein or brachial plexus as it crosses the first rib. The female to male ratio is approximately 4:1. Neurological symptoms are the most common presenting features but embolic phenomena from a subclavian artery aneurysm of an acute axillary vein thrombosis are occasionally the presenting features. Trauma, such as a whiplash injury can occasionally precipitate presentation.

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55. Abdominal aortic aneurysms

(a) Risk factors include male sex, smoking and hypertension
(b) With a diameter of greater than 7 cm have a less than 20% risk of rupture at 5 years
(c) Elective surgery usually has mortality of less than 5%
(d) Emergency surgery may have a mortality of greater than 50%
(e) Over 80% of patients die from an unrelated cause

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only b wrong. Abdominal aortic aneurysms are more common in men and the incidence increases with age. The risk of rupture of 7 cm AAA is over 70% at 5 years. Most centres report a 30-day operative mortlaity for elective aneurysm surgery of less than 5%. For emergency surgrey the morlality is about 50%. Furthermore, half of all patients that rupture in the community never reach hospital alive. More patients die with than from an abdominal aortic aneurysm.

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56. In the non-invasive assessment of the arterial system

(a) A 5 MHz doppler probe is better than an 8 MHz probe
(b) The ABPI is the ratio of the ankle to brachial diastolic pressure
(c) A normal ABPI is greater than 1.0
(d) Patients with critical limb ischaemia usually have an ABPI of greater than 0.4
(e) Distal to an arterial stenosis the pressure increases with exercise

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only c is right. The 8 MHz doppler probe is optimal for assessment of the arterial tree. The ABPI is the ratio of the ankle to brachial systolic pressures. An normal ABPI is greater than 1.0. In critical limb ischaemia the resting ABPI is usually less than 0.4. Distal to an aterial stenosis the ABPI falls with exercise and recover to resting pressur is delayed.

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57. Overwhelming post-splenectomy infection

(a) Is usually due to unencapsulated bacterial infection
(b) Strep. pneumoniae is the commonest aetiological agent
(c) Despite aggressive therapy it can have a mortality of over 50%
(d) The risk of infection can be reduced with pneumococcal and haemophilus vaccination
(e) Penicillin antibiotic prophylaxis should be considered in all children

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only a wrong . OPSI results from infection with encapsulated bacteria. Strep. pneumonia is the commonest implicated bacterium. All patients undergoing a splenectomy should have pneumococcal and haemophilus vaccination. Antibiotic prophylaxis with either penicillin or amoxycillin should be considered in children up to the age of 16 years.

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58. Regarding colonic polyps

(a) Juvenile rectal polyps are adenomatous polyps
(b) Metaplastic polyps are pre-malignant
(c) The risk of malignancy is higher in tubular than villous adenomas
(d) Villous adenomas occasionally cause hyperkalaemia
(e) All patients with untreated familial adenomatous polyposis will eventually develop colorectal carcinoma

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only e is right . Juvenile rectal polyps are hamartomatous polyps. Metaplastic polyps are not premalignant. Villous adenomas have a higher risk than tubular adenomas of being malignant. Villous adenomas occasionally present with hypokalaemia as a result of potassoium loss from their mucus secretion. Familial adenomatous polyposis is an autosomal dominant condition. Untreated all patients usually develop a colonic neoplasm by the age of 40 years. All patients at risk should be screened and if polyps are identified should be offered prophylactic surgery.

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59. Prostate carcinoma

(a) Affects 50% of men over the age of 80 years
(b) Most present with symptoms of bladder outflow obstruction
(c) A serum prostate specific antigen concentration of greater than 10 ng/ml is highly suggestive of the diagnosis
(d) Over 80% of tumours are androgen dependent
(e) In the treatment of the disease flutamide acts as an anti-androgen

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all are true . The prevalence of prostate carcinoma increases with age. It affects 50% of men greater than 80 years but many are asymptomatic. 70% of patients present with bladder outflow obstruction. 10% of patients are idenfified as an incidental find at TURP. Most tumours are androgen-dependent. Their growth can be reduced surgically by a bilateral subcapsular orchidectomy. Pharmacologically the same can be achieved with LHRH agonsits (e.g. goseralin)or antiandrogens (e.g. cyproterone acetate, flutamide)

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60. Hodgkin's lymphoma

(a) Often presents as painless cervical lymphadenopathy
(b) About 50% of patients have splenomegaly at presentation
(c) The nodular sclerosing type has the best prognosis
(d) Stage 3 disease has lymphadenopathy confined to one side of the diaphragm
(e) With modern radiotherapy techniques stage 1 disease has a 5-year survival of over 90%

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a , b , e are right . Painless cervical lymphadenopathy is the commonest presentation of Hodgkin's lymphoma. The lymphocyte predominant type has the best prognosis. The nodular sclerosing variety has the worst. Stage 2 disease is confined to one side of the diaphragm. Stage 3 disease has nodal involvement on both sides of the diaphragm. With modern radiotherapy techniques, Stage 1 disease (i.e. localised to one nodal group) has a 5-year survival of more than 90%.

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