An accident in a dry cleaning facility exposes an employee to massive amounts of carbon tetrachloride, both on the skin and by inhalation. Severe damage to which of the following organs is most likely to occur?

A 26-year-old woman accidentally inhales a peanut while laughing hysterically at a comedy club. Her friends bring her to a nearby emergency department, where it is revealed that the peanut is lodged in her right mainstem bronchus. Which of the following is true about the blood flowing through the area of lung distal to the peanut?

A 61-year-old woman has severe chest pain and shortness of breath. She has smoked a pack of cigarettes a day for the past 30 years and has a history of poorly controlled hypertension. An electrocardiogram shows ST segment elevations greater than 1 mm in two contiguous leads, a new Q waves. Laboratory studies show elevated levels of creatine kinase-MB and troponin I. The earliest pathologic evidence that this event has occurred consists of

A blood sample from a patient with polycythemia vera is sent for complete blood count. Which of the following blood components is most likely to be reported within normal limits?

On a routine physical examination for medical insurance, a midsystolic ejection murmur is detected in the pulmonic area of a 35-year-old female executive. The cardiac examination also reveals a prominent right ventricular cardiac impulse and wide and fixed splitting of the second heart sound. An EKG shows right axis deviation, and a chest x-ray film shows enlargement of the right ventricle and atrium. Which of the following is the most likely diagnosis?

A 29-year-old woman with a history of pelvic inflammatory disease presents to the emergency department with severe left lower quadrant crampy pain and spotting, and amenorrhea for the past two cycles. Physical examination reveals a left adnexal mass with tenderness to palpation. The beta-human chorionic gonadotropin (hCG) level is elevated. Further studies would most likely reveal an implantation at which of the following locations in the fallopian tube?

A 24-year-old medical student comes to the student health center because of a “skin problem”. She has no other complaints at this time. A physical examination is performed, and the physician gives the most likely diagnosis, explaining that her dermatologic condition is likely caused by hypersensitivity to an antigen that is taken up by Langerhans cells. These antigen-presenting cells process antigens and present them to naïve CD4-positive T cells. Antigen re-exposure leads to recruitment of helper T cells and release of cytokines that mediate the inflammatory response. Which of the following dermatologic conditions is mediated by this type of hypersensitivity reaction?

A 55-year-old man with a history of recurrent calcium-containing renal stones presents to the emergency department with excruciating flank pain and blood in the urine. This patient is likely to have which of the following underlying disorders?

A 22-year-old man with fatigue, recurrent fever, and enlarged cervical lymph nodes has numerous atypical lymphocytes in his peripheral blood smear. A biopsy from the patient’s enlarged node shows expansion of lymphoid follicles with preservation of the underlying architecture. Numerous atypical lymphocytes are present in the paracortical areas. Which of the following is the most likely diagnosis?

A 65-year-old man complains of weakness, weight loss, and bone pain. He reports having progressive difficulty seeing. Physical examination is significant for hepatosplenomegaly and lymphadenopathy. Serum protein electrophoresis reveals an M-protein spike, with an elevated serum IgM level. Bone marrow aspiration shows intensely eosinophilic plasma cells. Urine contains Bence-Jones proteins. Which of the following id the most likely diagnosis?

A 57-year-old man presents with painless swelling in his neck. Physical examination is remarkable for splenomegaly. Biopsy of the neck mass reveals a neoplasm containing small, cleaved cells that recapitulate the normal follicular architecture of lymph nodes. Which of the following mechanisms is most likely involved in the development of this patient’s neoplasm?

A gastroenterologist performs a colonoscopy on a patient with a family history of gastric and colon cancer and discovers multiple polyps. Biopsy of one lesion reveals a benign hamartoma. On physical examination the patient is noted to have dark pigmentation of the buccal mucosa and lips. What is the most likely diagnosis?

A 40-year-old man who recently immigrated from Japan presents to his physician with abdominal discomfort characterized by sensations of fullness and mild pain after eating. He was previously diagnosed with a gastric ulcer, which has been refractory to traditional treatment. Biopsy of the lesion reveals gastric carcinoma. The cancer is most likely located in which of the following regions of the stomach?

A 14-year-old bot is brought to the physician because his mother noticed that his face looked puffy. The bot has no complaints, other than a recent upper respiratory infection that has resolved. No significant medical history is evident except for hay fever during the spring and summer. On examination, the boy is normotensive, has significant periorbital swelling, and demonstrates 1+ pitting edema of both extremities. Urine dipstick reveals 3+ proteinuria and no blood, no casts are seen on microscopic examination. Twenty-four-hour urine reveals 3.7 g/day protein. Serum albumin is 2.4 g/dL, and LDL cholesterol is 290 mg/dL. A renal biopsy would reveal which of the following on light microscopic examination?

The 10-year-old daughter of a United Nations ambassador in Turkey develops a severe sore throat, which resolves after a few days. Ten days later, the mother notices dark strains on the child’s underwear and takes her to the pediatrician. A urine sample appears smoky, and red cells casts are noted in the urinary sediment. If a renal biopsy were obtained from this child it would probably show

A 46-year-old woman who is clearly jaundiced is seen in clinic. Laboratory tests reveal conjugated hyperbilirubinemia. Urine bilirubin levels are significantly above normal, while urine urobilinogen levels are significantly below normal. Which of the following mechanisms is the most likely cause of her jaundice?

A 53-year-old woman comes to the physician because of fatigue. She reports that she has been weak and tired for the past few months and has lately been feeling palpitations. She has no chronic medical conditions, does not take any medications or smoke cigarettes, and does not use drugs or alcohol. Laboratory studies show a normochromic anemia with no reticulocytes. The red blood cell morphology is normal. Platelets and myeloid cells are unaffected. Bone marrow biopsy is normocellular and is significant for a lack of erythroid precursors, but all other elements are normal. As part of the management of her condition she should be evaluated for which of the following?

A 75-year-old man with a 5-year history of stable angina pectoris is brought to the emergency department with severe chest pain. EKG reveals profound ST segment elevations, and the CK-MB level is elevated. On stabilization, the patient is admitted to the coronary care unit for further management. Several days later, the patient again complains of chest pain. Physical examination is significant for fever, loud pericardial friction rub, mild pulmonary rales, and 1+ pitting edema of the lower extremities. Which of the following is the most likely diagnosis?

Conjoint twins are born attached at the chest. Examination of the placenta would likely reveal which of the following arrangements of the fetal membranes?

A 56-year-old man presents with complains of gnawing pain in the mid-epigastrium, with occasional radiation to the back. He also notes a 15-pound weight loss over the past 3 months. The clinical suspects pancreatic carcinoma. Which of the following tumor markers would aid in confirming this diagnosis?

A 45-year-old woman presents with recent onset of blood-tinged discharge from the right nipple. The nipple appears slightly retracted, and an ill-defined subareolar nodule can be appreciated on palpation. Mammographic examination reveals linear shadows attributable to calcification. An excisional biopsy is performed. Microscopically, the lesion consists of markedly dilated ducts that contain inspissated secretion and are surrounded by fibrosis and chronic inflammation. Focal calcium deposition is present. Which of the following is the most likely diagnosis?

A 21-year-old woman attempts suicide by taking an overdose of barbiturates. On arrival in the emergency department, her blood pressure is 95/65 mm Hg, and her pulse is 105/min. The physician in the intensive care unit orders arterial blood gases. Which of the following values would you expect in this patient?

A 13-year-old boy presents to the emergency department with a deep skin abrasion on his knee. He states that it has not stopped bleeding since it happened during recess approximately 20 to 30 minutes ago. Physical examination reveals a well-developed, well-nourished adolescent. There are multiple purpura over his legs and arms, and a few scattered petechiae on his chest and gums. His bleeding time = 22minutes, platelets = 300.000/mm3, and hemoglobin = 11 g/dL. A trial of cryoprecipitate transfusion does not improve his bleeding time, but a normal platelet transfusion does. Which of the following is the correct diagnosis?

Which of the following histologic changes in the kidney would be caused by proteinuria?

The EKG of a 60-year-old man revels QRS intervals of 0.14 seconds with distinctly abnormal configurations. Physical exam is significant for paradoxical splitting of the second heart sound. Which of the following conduction defects is likely in this patient?

A 46-year-old woman presents to her physician complaining of weakness and fatigue, on physical examination, her physician notices a 10-lb weight gain since her last visit 6 months ago. Her blood pressure is 160/100 mm Hg. Blood tests reveal serum Na+ 155 mEq/L, K+8 mEq/L, and decreased serum rennin. Which of the following is the most likely diagnosis?

A patient has a lymphoproliferative disorder containing mature B cells that mark weakly with kappa light chain on the plasma membrane, strongly with CD5, strongly with CD23, and weakly with CD22. Which of the following is the most likely diagnosis?

A 36-year-old man with ulcerative colitis develops pruritus and fatigue. Alkaline phosphatase is elevated. The biliary tree appears beaded on ERCP. Which of the following is most likely diagnosis?

A 65-year-old woman with an 8-year history of type 2 diabetes dies in the hospital. She had no other significant medical history. Which of the following was the most likely cause of death?

During a routine pre-employment examination chest x-ray, a 37-year-old man is found to have a 4-cm mass on his left lung. A chest x-ray taken 3 years ago is normal. The patient does not smoke cigarettes, nor does anyone with whom he comes into daily contact. He works as manager of a supermarket and has no chronic medical conditions. Both of his parents are alive and well. He undergoes surgery, and pathologic examination of the lesion reveals that it is a primary lung cancer. Which of the following is the most likely type of cancer in this patient?

A 6-year-old child has an eye surgically enucleated because it contains a retinoblastoma. To which of the following structures should the pathologist pay particular attention when evaluating the specimen?

A 37-year-old woman presents to her physician complaining of difficulty reading and fatigue. She reports having had a “pins and needles” feeling in her left arm several months ago that resolves without treatment. On examination, visual field deficits and mild hyperreflexia are noted. MRI confirms the suspected diagnosis. Which of the following is the underlying mechanism of this patient’s disease?

A 14-year-old boy presents with a 1-month history of knee pain and a 6-pound weight loss. He is pale and afebrile. An x-ray film reveals a densely sclerotic lesion in the distal femur extending from the growth plate into the diaphysis. The periosteum is lifted, forming an angle with the cortex. The surrounding soft tissue resembles a “sunburst” on the radiograph. Which one of the following is the most likely diagnosis?

A 27-year-old man presents with recurrent episodes of intensely pruritic vesicles symmetrically distributes on his trunk. On electron microscopy, granular deposition of IgA and complement is noted at the dermoepidermal junction. Which of the following underlying conditions predisposes patients to the described skin disorder?

A 40-year-old alcoholic woman presents with intense pruritus and fatigue. Her medical history is significant for hypothyroidism. Physical examination reveals a slightly enlarged liver and xanthomas. Laboratory studies show a cholesterol of 538 mg/dL and alkaline phosphatase of 571 IU/L. which of the following serum values would most likely be elevated?

A 25-year-old with a history of substance abuse and gonorrhea presents with fever and shortness of breath. Pulse oximetry reveals hypoxia. A chest x-ray film is significant for bilateral interstitial infiltrates. Which of the following findings is consistent with the most likely diagnosis?

A 70-year-old man experiences continuous lower abdominal discomfort with alternating constipation and diarrhea. His symptoms seem to improve on a high-fiber diet. If exploratory surgery were performed, which of the following would the surgeon most likely to see?

A 5-year-old boy, hospitalized for cellulitis, exhibits global denudation of the skin resulting from splitting of the epidermis at the stratum granulosum. Which of the following is the most likely diagnosis?

A 25-year-old, previously healthy man notices that he now develops painful muscle cramps after strenuous exercise. After shoveling 2 feet of snow off his driveway, his urine turns red, and he consults a physician. Which of the following genetic conditions does the patient most likely have?

A 56-year-old man presents with higher-than-normal language output and frequent paraphasic errors. Neurologic testing reveals that his comprehension of auditory and visual language is severely disturbed. He also exhibits an inability to repeat language. This patient has which of the following types of aphasia?

A 73-year-old man is concerned about aging. He says that his skin is beginning to sag and his body “just doesn’t work like it used to”. He has no other complaints and leads a healthy lifestyle. Physical examination is consistent with a healthy man his age. Routine laboratory studies are within normal limits. On his way out of the physician’s office, he sees a flyer asking for healthy, elderly volunteers. He enrolls in the study and undergoes a liver biopsy to evaluate the aging process. In this biopsy, which of the following substances will indicate aging at a cellular level?

A 35-year-old woman complains of vomiting dark, greenish material approximately 1 hour after eating. She is scheduled for an upper GI study to evaluate the upper portion of the gastrointestinal tract. She denies pain and is anicteric. Which of the following is the most likely cause of this woman’s condition?

Biopsy of a skin lesion shows marked intercellular edema that splays apart adjacent cells, leaving only thin dark lines between the cells. What is this process called?

A 41-year-old obese woman with a history of biliary colic presents with right upper quadrant discomfort and pain in her right shoulder after eating a fatty meal. Physical examination is significant for marked right upper quadrant tenderness during inspiration. Which of the following structures is most likely involved in producing her shoulder pain?

A 60-year-old man suddenly becomes completely blind in one year. Angiography demonstrates occlusion of the central retinal artery. Which of the following is the most likely cause of the occlusion?

A 36-year-old gravid woman notes vaginal bleeding. Ultrasound reveals small grape-like cystic structures without evidence of a developing embryo. A diagnosis of complete hydatidiform mole is made at the hospital. Further analysis is most likely to reveal that