9th INTEGRATED SURGICAL COURSE

1. 8/31/2012 1 9th INTEGRATED SURGICAL COURSE Prepared by: Dr. Mohammed Al-Naami, FRCSC, FACS Associate Professor & Consultant General Surgeon

2. 8/31/2012 2

3. 8/31/2012 3 Is considered idiopathic in about one-third of all cases Has been associated with hydralazine, ergotamine, methyldopa, and alpha-blocking agents Is excluded if only one ureter appears to be involved Can be treated surgically with ureteral transportation, renal auto-transplantation, or omental encasement Cannot be accurately diagnosed with intravenous pyelography ANSWER: D

4. 8/31/2012 4 EXPLANATION Retroperitoneal fibrosis is a rare condition, and is idiopathic in etiology in about two-thirds of all cases (usually called Osmond�s disease). An association with various medications has been shown, which include methysergide, ergotamine, hydralazine, methyldopa, and beta-blocking agents. The key characteristic of retroperitonel fibrosis is its effect on the ureters which pass through it. Constriction leading to obstruction is the result of entrapment of the ureters , which will vary the presentation based on severity of the obstructive uropathy. Intravenous pyelogram (IVP) usually provides an accurate diagnosis, with characteristic signs of medial displacement, hydronephrosis/hydroureter proximal to the lesion, and a long segment of affected ureter. The strictures are usually bilateral and symmetrical, however, only one ureter may be involved.

5. 8/31/2012 5 Mild cases with low-grade obstruction can be treated initially with medical management. This involves steroids and cessation of any associated medications. Failure of this regimen is seen by the lack of improvement over several week, and surgical management should be considered at this time. High grade or severe cases of obstruction will require surgical management and perhaps immediate nephrostomy if indicated. The cornerstone of surgical management is liberation of the ureters from the retroperitoneum. Concomittant intraperitoneal transposition of the ureters may be required, and encasement with ometum may also be necessary. Renal autotransplantation should also be considered, given its low complication risk. EXPLANATION�cont

6. 8/31/2012 6 2. Primary retroperitoneal tumours:

7. 8/31/2012 7 Are malignant in 60-85% of all cases Are classified as either mesodermal or neurologic in origin, the latter of which comprises the majority of these tumors Can be clearly defined with a combination of magnetic resonance imaging (MRI) and computed tomography (CT); angiography, however, shows limited utility in their evaluation Can be effectively treated with partial resection and chemotherapy, with a significant improvement in medium survival at 5 years Are mostly found to have low histologic grade and be of small (<5cm) size at the time of diagnosis ANSWER: A

8. 8/31/2012 8 EXPLANATION Retroperitoneal tumours are challenging both in diagnosis and in treatment. The majority of retroperitoneal tumors are discovered well after they have involved contiguous structures and organs. They are a rare phenomenon with an incidence of 0.3-3%, and are classified as either mesodermal or neural in origin. Overall, retroperitoneal tumors are malignant 60-85% of the time, with the majority of malignant 60-85% of the time, with the majority of malignant tumours being mesodermal in origin. Diagnosis and determination of resectability is based on a combination of CT, MRI and angiography. Evaluation of retroperitoneal soft tissue sarcomas has shown that the majority are greater than 10 cm in size (60%) and have a high-grade histology (64%) at presentation. Most common presenting symptoms include a palpable abdominal mass, lower extremity neurologic symptoms, and pain.

9. 8/31/2012 9 In terms of treatment, the primary treatment should be aimed at complete resection of tumor. Complete resection of primary disease provides a median survival time of 103 months, while incomplete and no resection provides a medium survival of 18 months. Analysis of median survival times has shown that incomplete resection does not provide significant increase in survival than chemotherapy (doxorubicin based) and/or radiation therapy for unresectable tumors. However, partial resection has been shown to provide some symptomatic relief, and thus should be reserved for cases in which partial resection may provide palliation. Overall high-grade histology, unresectability, and positive gross margin are the strongest factors negatively influencing survival for these tumours. EXPLANATION�cont

10. 8/31/2012 10 3. According to current guidelines for the management of retroperitoneal hematomas:

11. 8/31/2012 11 Zone 3 hematomas due to penetrating injury in a stable patient should be managed non-operatively, with pelvic angiography to determine potential sites for embolization Exploration of non-expanding stable zone 2 hematomas due to blunt trauma increases the likelihood of renal injury and/or loss of the kidney Supramesocolic zone 1 hematomas should first be approached by gaining control of the abdominal aorta via the midline posterior peritoneum at the supraceliac aorta The most common site of blunt trauma to the abdominal aorta is at the origin of the superior mesenteric artery (SMA) Infrarenal lacerations of the abdominal aorta are associated with the highest mortality rate ANSWER: B

12. 8/31/2012 12 EXPLANATION The retroperitoneum is roughly divided into three major anatomic zones. Zone 1 is the midline retroperitoneum and contains the suprarenal abdominal aorta, IVC, superior mesenteric and proximal renal arteries. A hematoma in this area should warrant exploration for both blunt and penetrating trauma, as the likelihood of major vessel injury is high. The transverse mesocolon provides the boundary between the two types of zone 1 hematomas. Supramesocolic hematomas usually arise from aortic, celiac, proximal SMA, or renal arterial injuries. Vascular control should begin with clamping of the abdominal aorta at the diaphragmatic hiatus and left-sided medial visceral rotation (Mattox maneuver). Inframesocolic hematomas generally arises from aortic or inferior vena caval injuries. Proximal control should be at the supraceliac aorta, with exposure via the posterior peritoneum in the midline similar to approaching an infrarenal aortic aneurysm.

13. 8/31/2012 13 Zone 2 of the retroperitoneum are the paired perinephric spaces, which contain the kidneys and renal vessels. Hematomas resulting from blunt trauma in zone 2 warrant exploration only if there is expansion or instability, as studies have shown an increase in subsequent loss of the kidney otherwise. Given the need for exploration, some centers advocate obtaining proximal control of the renal vessels at the aorta prior to incising Gerota�s fascia. Other centers incise the fascia and clamp the hilum after medially rotating the kidney. Regardless, evaluation of injury along with watertight closure of the collecting system should remain the primary goals. Zone 3 is the pelvic retroperitoneum, and contains the iliac vessels and the ureters. Blunt trauma resulting in non expanding stable hematomas are often secondary to pelvic fracture or bleeding which is most likely best controlled by angiographic embolization and thus should not be explored. Blunt expanding hematomas in this area should be explored given the likelihood of iliac vessel injury. EXPLANATION�.continue!

14. 8/31/2012 14 4. Rectus sheath hematomas:

15. 8/31/2012 15 Can be caused by coughing Are rarely associated with anticoagulative therapy Usually occur at the semicircular line of Douglas at the entry site of the superior epigastric artery into the rectus sheath Are infrequently palpable on physical examination Usually require operative drainage ANSWER: A

16. 8/31/2012 16 EXPLANATION Rectus sheath hematomas may mimic intra-abdominal disease, and so care should be taken with diagnosis to avoid an unnecessary laparotomy. Trauma is the primary cause of rectus sheath hematomas, and may be caused by various blunt traumas or even vigorous paroxyms of coughing. Other causes include collagen vascular diseases, and infectious disease like typhoid fever. Also many patients with this condition are frequently on anticoagulative therapy or have some type of blood dyscrasia. Most often, the source of bleeding is usually from the inferior epigastric vessels and not the muscle proper. Logically, it occurs most often at the junction of the semicircular line of Douglas and the rectus sheath where the inferior epigastric vessels enter the rectus sheath. Likewise, abdominal CT scanning or ultrasonography should adequately reveal a rectus sheath hematoma. Management is most often non-operative, although continued expansion of the hematoma may warrant operative therapy. This should usually involve simple evacuation, control of hemorrhage, and closure without drainage, Operative therapy is also indicated if more serious, intraabdominal conditions cannot be excluded in the process of diagnosis.

17. 8/31/2012 17 5. A pneumoperitoneum of less than 20 mm Hg is associated with which of the following observed changes in the following cardiac parameters: mean arterial pressure (MAP), systemic vascular resistance (SVR), and central venous pressure (CVP)?

18. 8/31/2012 18 Increased MAP, increased SVR, increased CVP. Decreased MAP, decreased SVR, increased CVP. Increased MAP, decreased SVR, decreased CVP. Decreased MAP, decreased SVR, decreased CVP. Increased MAP, increased SVR, decreased CVP. Answer: A

19. 8/31/2012 19 Explanation: Creation of pneumoperitoneum to an intraabdominal pressure of less than 20 mm Hg is associated in the supine position with increased MAP, SVR, and cardiac filling pressures. These effects stem from direct mechanical effects of the pneumoperitoneum, myocardial and vasodilatory effects of carbon dioxide, and sympathetic stimulation.

20. 8/31/2012 20 Explanation�cont

21. 8/31/2012 21 Explanation�.cont. SVR increases secondary to increased venous resistance, compression of the intraabdominal arterial tree by the pneumoperitoneum, and sympathetic or other chemical actions leading to increased after load. Increased SVR helps create an increased MAP.

22. 8/31/2012 22 Explanation�cont. In addition to these changes, cardiac output is decreased. Stroke volume is limited secondary to chemical mediators, specifically hypercarbia, that restrict cardiac contractility. For all these reasons, laparoscopic surgery with pneumoperitoneum is still used cautiously in the frail and elderly patients with limited cardiac or respiratory reserve.

23. 8/31/2012 23 6. You are insufflating the abdomen of an otherwise healthy 35-year-old female for laparoscopic cholecystectomy when the patient becomes severely bradycardic. What should be your next course of action?

24. 8/31/2012 24 Continue with laparoscopic cholecystectomy Administer 1 mg epinephrine Deflate the abdomen Place the patient in Trendelenburg position Administer 10 mg procurium Answer: C

25. 8/31/2012 25 7. In sufflation of the peritoneum with CO2, has several effect on CO2 excretion and arterial CO2. Which of the following effects is correct?

26. 8/31/2012 26 Linearly increasing CO2 excretion; linearly increasing PaCO2. Increase, then plateau of CO2, excretion; linearly increasing PaCO2. Increase, then plateau of CO2 excretion; increase, then plateau of PaCO2. Unchanged CO2, excretion, unchanged PaCO2 Decreased CO2, excretion, increasing PaCO2. Answer: B

27. 8/31/2012 27 Explanation Excretion of CO2, increases as insufflation pressure increases from 0 to 10 mmHg, but then plateau with insufflation pressure greater than 10 mmHg. CO2 excretion is proportionally related to absorption, and the increase and plateau in CO2, excretion may be caused by the initial increase in peritoneal surface area exposed to the CO2 which then stabilizes as the peritoneum becomes distended and has no more surface area to absorb additional CO2. PaCO2, however, increases continuously as insufflation increases from 0 to 25 mmHg as dead space increases.

28. 8/31/2012 28 8. Which of the following factors is not associated with postoperative nausea and vomiting?

29. 8/31/2012 29 Postoperative opioids Female gender Previous history of postoperative nausea History of migraine Smoking Answer: E

30. 8/31/2012 30 Explanation The most important predictor of postoperative nausea and vomiting is previous history of postoperative nausea. Other predictors include postoperative opioids, female gender, history of migraines, history of motion sickness, length of operation, and history of nonsmoking.

31. 8/31/2012 31 According to the National Institutes of Health (NIH) Consensus Development Conference Statement, patients interested in weight loss surgery for treatment of clinically severe obesity must satisfy several qualification for bariatric surgery. Which one is not qualified NIH recommendation?

32. 8/31/2012 32 Body mass index (BMI) greater than 35 kg/m2 with a medical co-morbidity related to morbid obesity BMI greater than 40 kg/m2 Age <18 Poor outcomes with nonsurgical methods including dieting, exercise, and behavioral modifications Understanding of the surgical risks and demonstrated follow-up with previous methods of weight loss ANSWER: C

33. 8/31/2012 33 EXPLANATION The NIH Consensus Development Conference Statement summarizes the conclusions obtained following a 2-day conference in March 1991. Several basic patient criteria were recommend and included the following BMI >40 kg/m2 or BMI >35 kg/m2 with a minimum of one medical commorbidity related to obesity (e.g., sleep apnea, Pickwickian�s syndrome, diabetes, mellitus, joint disease, gastroesophageal reflux disease, and so on), a demonstrated low probability to be successful with nonsurgical weight loss measures, and demonstrated ability to participate and maintain follow-up on a long-term basis.

34. 8/31/2012 34 EXPLANATION�cont! The consensus panel was unable to agree on any conclusions regarding surgical weight loss treatment of children or adolescents, even subjects with BMI >40 kg/m2. Although several centers perform weight loss surgery on adolescents, the appropriate treatment for these patients is not determined. Many feel the gastric bypass (GBP) is too radical an approach; however, obesity during the important development stage adolescent may lead to significant psychologic sequela currently underestimated by the medical community. Continued study is necessary.

35. 8/31/2012 35 10. Several surgical weight loss procedures have been performed during the development of bariatric surgery. Roux-en-Y gastric bypass procedures (GBP) is the most commonly performed bariatric procedure in the United States. Outcomes following weight loss procedures are frequently reported in excess body weight (EBW) loss. EBW is equal to the difference of a patient�s presurgical weight and his or her ideal body weight. How much EBW can a patient expect to lose at 2-years following a Roux- en-Y GBP?

36. 8/31/2012 36 ANSWER: C 15% 31% 65% 86% 100%

37. 8/31/2012 37 EXPLANATION The common goal for all bariatric surgical procedures is achieving weight loss and obtaining its beneficial effect on the treatment or prevention of obesity related medical comorbidities including hypertension, coronary artery disease, and diabetes mellitus. Roux-en-Y GBP, initially described by Mason and Ito, is currently the most commonly performed bariatric procedure. It uses a restrictive gastric pouch with a small outlet. This pouch is drained by a Roux intestinal limb that causes malabsorption as food bypasses the distal stomach , entire duodenum, and the proximal jejunum. Although both a traditional open and a laparoscopic approach are both available, weight loss results appear to be similar.

38. 8/31/2012 38 11. AGB has gained significant exposure in Europe and Australia since the development of laparoscopic approach. It is becoming more popular in the united States, but results in the United States do not coincide with results seen abroad. Proponents emphasize the benefits of gastric banding compared to the time honored GBP. Which of the following comparisons is not accurate?

39. 8/31/2012 39 Gastric banding is more easily reversible compared to Roux-en-Y GBP Long-term weight loss (5 years) following successful gastric band is similar to the weight loss following Roux-en-Y GBP Mortality and gastrointestinal leak are higher following Roux-en-Y GBP AGB provides similar weight loss results as GBP in the super obese patient with BMI >50 kg/m2 Medical comorbidities improve equally well following gastric banding and GBP ANSWER: D

40. 8/31/2012 40 EXPLANATION Use of AGB remains controversial in the United States for treatment of clinically severe obesity. Results provided by large centers located in Europe and Australia demonstrate excellent long-term weight loss and resolution of medical comorbidities. However, frequent reoperation and lack of reproducibility in patient populations in the United States have lead to a slow acceptance for the AGB.

41. 8/31/2012 41 EXPLANATION�cont! Removal of the AGB can be performed laparoscopically and essentially reverses many of the effects for AGB. In addition, long-term weight loss results for AGB rival those provided by open GBP. The literature is wanting for good long-term results of the laparoscopic GBP, but weigh gain 2-5 years following laparoscopic GBP is likely to mimic the open surgical procedure. In addition insertion of the AGB does not require division of the stomach or intestine. So, risk of gastrointestinal leak is much less following AGB. Mortality is much less after AGB because of its limited nature; however, AGB appears to be most effective in patients with a lower BMI. Patients with BMI >50 kg/m2 lose more weight following GBP than AGB. Other patient populations appear to respond differently to the band as well including males and Black patients.

42. 8/31/2012 42 12. A 41-year-old man complains of regurgitation of saliva and of ingested but undigested food. An esophagram reveals a bird-beak deformity. Which of the following statements is true about this condition?

43. 8/31/2012 43 Answer: C Chest pain is common in the advanced stages of this disease. More patients are improved by forceful dilatation than by surgical intervention Manometry can be expected to show high resting pressures of the lower esophageal sphincter. Surgical treatment primarily consists of resection of the distal esophagus with reanastomosis to the stomach above the diaphgram Patients with this disease are at no increased risk for the development of carcinoma

44. 8/31/2012 44 13. A 46-year-old man had a long history of heartburn (GERD). His x-ray showed an irregular, ulcerated area in the lower third of the esophagus. There are marked mucosal disruption and over hanging edges. What is the most likely diagnosis?

45. 8/31/2012 45 Answer: E Sliding hiatal hernia with GERD Paraesophageal hernia Benign esophageal stricture Squamous carcinoma of the esophagus Adenocarcinoma arising in a Barrett�s esophagus

46. 8/31/2012 46 Explanation The history of GERD with these findings is highly suggestive of an adenocarcinoma arising in a Barrett�s esophagus. Squamous carcinoma is more likely to occur higher up in the middle third of the esophagus. Endoscopy and biopsy prove the diagnosis. The patient should be treated surgically by esophagectomy if carcinoma is confirmed.

47. 8/31/2012 47 14. A 46-year-old man presents with dysphagia of recent onset. His esophagram shows a lesion in the lower third of the esophagus, which, on endoscopy shows 2 cm ulcer, and biopsy, proves to be an adenocarcinoma. His general condition is excellent, and his metastatic workup findings are negative. What should he undergo?

48. 8/31/2012 48 Answer: D Chemotherapy Radiotherapy Insertion of a wide esophageal tube to improve swallowing Surgical resection of the esophagus A combination of chemotherapy and radiotherapy

49. 8/31/2012 49 Explanation Surgical resection of the esophagus remains the standard treatment for patients with carcinoma in the lower esophagus, provided that there is no known metastatic disease, and the medical condition allows surgical intervention. This offers the best palliation and hope of cure; 5-year survival rates vary between 15 and 25%. Radiation and chemotherapy, in combination with surgery in selected patients, may improve these statistics. Management of carcinoma in the middle third of the esophagus may be either surgical resection or radiotherapy, and in the upper third, radiotherapy is often preferred.

50. 8/31/2012 50 15. A 33-year-old female arrives to the emergency department following a suspected suicide attempt in which she swallowed an unknown cleaning solution. The patient is obtunded and unable to provide any history. Vital signs are as follows: temperature 38oC, BP 136/88 mmHg, HR 114 bpm, RR 32 breaths/min. On examination, she is drooling from the mouth and there are visible burns in the oropharynx and crepitus in the neck and upper chest. All of the following are appropriate except:

51. 8/31/2012 51 Endotracheal intubation Administer broad-spectrum intravenous antibiotics Perform endoscopy Administer intravenous corticosteroids Admit to ICU Answer: D

52. 8/31/2012 52 References Zwischenberger JB, Alpard SK, Orringer MB. Esophagus. In: Townsend CM, Beauchamp DR, Evers MB, et al. (eds), Sabiston Textbook of Surgery: The Biological Basis of Modern Surgical Practice, 16th ed. Philadelphia, PA: WB. Saunders, 2001, 717-719.

53. 8/31/2012 53 16. A 62 year-old woman is seen after a 3-day history of fever, abdominal pain, nausea, and anorexia. She has not urinated for 24h. She has a history of previous abdominal surgery for inflammatory bowel disease. Her blood pressure is 85/64, and her pulse is 136. Her response to this physiologic state includes which of the following?

54. 8/31/2012 54 ANSWER: D Increase in sodium and water excretion Increase in renal perfusion Decrease in cortisol levels Hyperkalemia Hypoglycemia

55. 8/31/2012 55 EXPLANATION The biochemical changes associated with shock result from tissue hypoperfusion, endocrine response to stress, and specific organ system failure. During shock, the sympathetic nervous system and adrenal medulla are stimulated to release catecholamines. Renin, angiotensin, antidiuretic hormone, adrenocorticotropin, and cortisol levels increase. Resultant changes include sodium and water retention and an increase in potassium excretion, protein catabolism, and gluconeogenesis. Potassium levels rise as a result of increased tissue release, anaerobic metabolism, and decreased renal perfusion. If renal function is maintained, potassium excretion is high and normal plasma potassium levels are restored.

56. 8/31/2012 56 17. A 24-year-old woman has acute renal failure following postpartum hemorrhage. Laboratory studies showed serum glucose, 150 mg/dL; sodium, 135 mEq/L; potassium, 6.5 mEq/L; chloride, 105 mEq/L; and bicarbonate, 15 mEq/L. Therapy should include which of the following?

57. 8/31/2012 57 Answer: C Decreased potassium chloride to 10 mEq/L Intravenous 0.9% sodium chloride 100 mL of 50% glucose water with 10 U insulin Intravenous calcitonin Intravenous magnesium sulfate

58. 8/31/2012 58 Explanation In hyperkalemia, all oral and intravenous potassium must be withheld. Sodium chloride worsens the metabolic acidosis. Sodium bicarbonate intravenously is given to divert potassium intracellularly by causing alkalosis. Calcium gluconate (1 g [10 mL of 10% solution]) is given to counteract the effect of potassium on the myocardium. The hypertonic glucose solution stimulates the synthesis of glycogen, which causes cellular uptake of potassium. Small amounts of insulin (1U/5 g of glucose) is helpful. The usual recommended dose is 100 mL of 50% glucose with 10 U of insulin. Calcitonin is used for treating hypercalcemia. Serum magnesium is also elevated in renal failure,

59. 8/31/2012 59 18. A 70-year-old woman has a small bowel fistula with output of 1.5 L/d. Replacement of daily losses should be handled using the fluid solution that has the following composition in mEq/L.

60. 8/31/2012 60 Answer: A Na K Cl HCO3 130 4 109 28 154 0 154 40 77 0 77 0 167 0 0 167 513 0 513 0

61. 8/31/2012 61 Explanation The composition of small-intestinal fluid is sodium, 140 mEq/L; potassium, 5 mEq/L; chloride, 104, 104 mEq/L; and bicarbonate, 30 mEq/L. Daily losses are best replaced by administration of balanced salt solution (Ringer�s lactate) whose composition is depicted in A.B represents normal saline (0.9%), C is half normal saline (0.45%), D is M/6 sodium lactate, and E is 3% sodium chloride.

62. 8/31/2012 62 19. A 70-year-old man has undergone anterior resection for carcinoma of the rectum. He is extubated in the operating room (OR). In the recovery room, he is found to be restless with a heart rate of 136 bpm and a blood pressure of 144/80 mmHg. ABG analysis on room air reveals pH, 7.24; PCO2, 60 mmHg; PO2, 54; HCO3, 25 mEq/L; and SaO2, 90%. The physiologic status can best be described as which of the following?

63. 8/31/2012 63 Respiratory alkalosis Respiratory acidosis Metabolic acidosis Metabolic alkalosis Combined respiratory and metabolic acidosis Answer: B

64. 8/31/2012 64 Explanation Decrease in pH below 7.4 indicates acidosis. PCO2 is increased over 40 mmHg, suggesting respiratory acidosis. To differentiate �pure� from �combined� acidosis, pH is calculated based on changes in CO2. A change of 10 mmHg from 40 mmHg changes pH by 0.08 from 7.4. In this case, there is a 20 mmHg increase in PCO2, which would decrease pH by 2 x 0.08 = 16 from 7.4 or 7.24. The measured pH is 7.24. Therefore, the patient has pure respiratory acidosis.

65. 8/31/2012 65 Explanation..cont Respiratory acidosis in the immediate postoperative period is due to inadequate ventilation. Adequate ventilation needs to be restored by prompt intubation and ventilatory support. Use of morphine will further depress the respiration.

66. 8/31/2012 66 20. A 19-year-old college student presents with a testicular mass, and after treatment he returns for regular follow-up visits. The most useful serum marker for detecting recurrent disease after treatment of non-seminomatous testicular cancer is:

67. 8/31/2012 67 Carcinoembryonic antigen (CEA). ?-fetoprotein (AFP) Prostate-specific antigen (PSA) CA125 p53-oncogene

68. 8/31/2012 68 Explanation In following patients with nonseminomatous testicular tumors, elevated serum levels of the � subunit of human chorionic gonadotropin (hCG), ?-fetoprotein, and lactic dehydrogenase have been found to be useful indicators of tumor activity or recurrence. The discovery of prostate-specific antigen has recently been touted as a major breakthrough in screening for prostate cancer, though some clinicians feel that early diagnosis may have no impact on survival in this disease. CA125 has been used to follow ovarian cancers, it is fairly nonspecific but can alert the physician to the need for more aggressive search for persistent disease when relative increases are noted in a patient after therapy. The p53 oncogenes have been found in soft tissue sarcomas, osteogenic sarcomas, and colon cancers. Their significance is unknown.

69. 8/31/2012 69 21. A 49-year-old woman undergoes surgical resection of a malignancy. The family asks about the prognosis. The histopathology is available for review. For which of the following malignancies does histologic grade best correlate with prognosis?

70. 8/31/2012 70 Lung cancer Melanoma Colonic adenocarcinoma Hepatocellular carcinoma Soft tissue sarcoma Answer: E

71. 8/31/2012 71 EXPLANATION The management of malignant tumors may be guided by knowledge obtained by grading and staging the tumors. Histologic grading reflects the degree of anaplasia of tumor cells. Tumors in which histologic grading seems to have prognostic value include soft tissue sarcoma, transitional cell cancers of the bladder, astrocytoma, and chondrosarcoma. Grading has been of little predictive value in melanoma, hepatocellular carcinoma, or osteosarcoma. Staging is based on the extent of spread rather than histologic appearance and is more relevant in predicting the course of lung and colorectal cancers.

72. 8/31/2012 72 22. A 37-year-old woman has developed a 6-cm mass on her anterior thigh over the past 10 months. The mass appears to be fixed to the underlying muscle but the overlying skin is movable. The most appropriate next step in management is:

73. 8/31/2012 73 Above knee amputation Excisional biopsy Incisional biopsy Bone scan Abdominal CT scan ANSWER: C

74. 8/31/2012 74 EXPLANATION Benign soft tissue tumors far outnumber their malignant counterparts. Because of this, prolonged delays are common before definitive treatment of soft tissue sarcomas is instituted. Risk of malignancy is increased for tumors greater than 5 cm in largest diameter, as well as for those lesions that are symptomatic or that have enlarged rapidly over a short period of time. Properly performed biopsy is critical in the initial treatment of any soft tissue mass. Improperly performed biopsies can complicate the care of the sarcoma patient, and in rare circumstances even eliminate certain surgical options. Excisional biopsies should be reserved for small masses for which complete excision would not jeopardize subsequent treatment should be performed. The incision should be placed directly over the mass and should be oriented along the long axis of the extremity.

75. 8/31/2012 75 23. A 50-year-old man is incidentally discovered to have non-Hodgkin�s lymphoma confined to the submucosa of the stomach during esophagogastro-duodenoscopy for dyspepsia. Which of the following statements is true regarding this condition?

76. 8/31/2012 76 Surgery alone cannot be considered adequate treatment . Combined chemotherapy and radiation therapy, without prior resection, are not effective. Combined chemotherapy and radiation therapy, without prior resection, result in a high risk severe hemorrhage and perforation. Outcome (freedom from progression and overall survival) is related to the histologic grade of the tumor The stomach is the most common site for non-Hodgkin�s lymphoma of the gastrointestinal tract. ANSWER: E

77. 8/31/2012 77 EXPLANATION The stomach is the most common site in the gastrointestinal tract for non-Hodgkin�s lymphoma, followed by the small intestine and the colon. Lymphomas constitute 3% of all malignant gastric tumors. Ninety percent of these lymphomas are of the non-Hodgkin�s type. Surgery alone can be considered adequate treatment for patients with non-Hodgkin�s lymphoma that does not infiltrate beyond the submucosa. However, gastric resection is not considered mandatory, and there no substantial differences in response to therapy, and survival when resection is compared with combined chemotherapy and radiation therapy, have been shown to be effective even in unresected bulky cases, and provide minimal risk of hemorrhage and perforation even this setting.

78. 8/31/2012 78 24. A patient with a hematologic malignancy seeks your advice. She has read on the commercial Internet that treatment with interferon might be helpful. Interferons are correctly characterized by which of the following statements?

79. 8/31/2012 79 They are a group of complex phospholipids They are produced by virus-infected cells They enhance viral replication They cause Burkitt�s lymphoma cell lines to divide They have not been effective in the treatment of hairy cell leukemias. ANSWER: B

80. 8/31/2012 80 EXPLANATION The interferons are a group of glycoproteins first found as products of virus-infected cells that inhibited viral replication. Subsequently, they have been shown to have a variety of effects both on cells of the immune system and on malignant cells. Interferons cause Burkitt�s lymphoma cell lines to differentiate and lose the capacity to divide. Hematologic malignancies are very responsive to interferons; up to 100% of hairy cell leukemias show some degree of remission. Interferon ? has been used in the treatment of chronic active hepatitis B and C with promising results in recent clinical trials.

81. 8/31/2012 81 25. A 33-year-old woman seeks assistance because of a swelling of her right parotid gland. Biopsy is performed and reveals acinar carcinoma. In your discussion regarding surgery, which of the following statements regarding malignant parotid tumors is correct?

82. 8/31/2012 82 ANSWER: D Acinar carcinoma is a highly aggressive malignant tumor of the parotid gland. Squamous carcinoma of the parotid gland exhibits only moderately malignant behavior. Regional node dissection for occult metastases is not indicated for malignant parotid tumors because of their low incidence and the morbidity of lymphadenectomy. Facial nerve preservation should be attempted when the surgical margins of resection are free of tumor. Total parotidectomy (superficial and deep portions of the gland) is indicated for malignant tumors.

83. 8/31/2012 83 EXPLANATION Acinar, adenoid cystic, and low grades of muco-epidermoid carcinomas exhibit moderately malignant behavior. Undifferentiated, squamous, and high grades of muco-epidermoid carcinomas are considered highly malignant tumors. Regional node dissection is indicated for malignant tumors because of the high (up to 50%) incidence of occult regional metastases. Facial nerve preservation should be attempted when the margins are adequate and the tumor is well localized. The minimal appropriate procedure for parotid carcinoma is a superficial parotidectomy with nerve preservation. The nerve must be partially or totally sacrificed if the tumor directly involves the nerve trunk or its branches.