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Free STEP3 Exam Braindumps (page: 54)

Page 53 of 202
PDF with 804 Questions

A40-year-old woman presents with headaches and visual disturbances for the past 6 months. She suddenly developed amenorrhea 2 years ago. One year ago, she noticed milky discharge from her left breast. The most likely diagnosis is which of the following?

  1. prolactinoma
  2. premature ovarian failure
  3. Kallman syndrome
  4. Sheehan syndrome
  5. polycystic ovarian syndrome (PCOS)

Answer(s): A

Explanation:

Galactorrhea with amenorrhea is consistent with hyperprolactinemia. The additional history of headache and possible visual field changes or cranial nerve abnormalities is strongly suggestive of a pituitary tumor. In this setting, the most likely diagnosis is prolactinoma. Ovarian failure, Kallman syndrome, and Sheehan syndrome would not present with galactorrhea. Kallman syndrome is associated with primary amenorrhea and anosmia. PCOS presents with a long history of irregular cycles and hyperandrogenism



A28-year-old woman was noted to have a 3 cm thyroid nodule at the time of a well-woman examination. Her mother and maternal aunt died of thyroid cancer. On examination, her BP was 160/105, heart rate 90/ minute. Laboratory studies:



Which of the following is the most likely diagnosis?

  1. papillary thyroid cancer
  2. follicular carcinoma with T3 toxicosis
  3. medullary thyroid carcinoma
  4. hyperfunctioning thyroid adenoma
  5. Hashimoto thyroiditis

Answer(s): C

Explanation:

The patient has a strong family history of thyroid cancer and has a thyroid nodule, hypertension, tachycardia, and hypercalcemia. These are hallmarks of Multiple Endocrine Neoplasia Type 2 (MEN-
2) syndrome, which is associated with medullary thyroid cancer, pheochromocytoma, and hyperparathyroidism. The very high calcitonin level is an excellent tumor marker for medullary thyroid cancer and a fine needle aspiration is not indicated. She will need to have an evaluation and treatment for pheochromocytoma prior to treatment of her thyroid cancer.



An 18-year-old man with a history of type I diabetes since age 14 presents to the clinic for further management. He notes several episodes of hypoglycemia at around 2 a.m. that awaken him from sleep since starting on his school's tennis team. He practices in the afternoon. His 8 a.m. glucose readings prior to breakfast are all greater than 200 mg/dL. His current insulin regimen is as follows: Breakfast: NPH 20 units with 5 units of regular insulin Supper: NPH 15 units with 5 units of regular insulin His average fingerstick glucose readings over the past week are as follows:



Which of the following recommendations would most likely improve his glucose control?

  1. Discontinue insulin and start metformin.
  2. Schedule NPH at bedtime instead of before supper.
  3. Discontinue regular insulin at supper.
  4. Advise the coach that he cannot play tennis.
  5. Increase the regular insulin at breakfast.

Answer(s): B

Explanation:

The patient has type I diabetes, therefore oral agents are contraindicated. The glucose pattern he has is known as the Somogyi phenomenon. His increased activity has made him more insulin sensitive, especially at the time of the day that he is most at risk of hypoglycemic reactions. When NPH is given at supper time, the peak action will be ~2 a.m. Changing the timing of the NPH to bedtime, will advance the peak to ~46 a.m., a time when the patient is becoming increasingly insulin resistant (Dawn phenomenon). As his glucose is already increasing at supper, discontinuing the regular insulin at that time may avoid nocturnal hypoglycemia, but at the expense of higher glucose values. Increasing the regular insulin at breakfast will likely cause hypoglycemia prior to lunch.



A 32-year-old male is seen in the ER with a nondisplaced fracture of the ulna after a fall. Incidentally, the intern noticed that the patient is jaundiced and has a palpable spleen. He orders a CBC which shows a Hgb of 10.2 g/dL. The patient reveals that he has chronic anemia and intermittently has been prescribed iron. On further questioning, he says that he had a cholecystectomy at age 23 and that he has family members with similar symptoms. The intern reviews the peripheral smear and finds spherocytes. What would be the best way to confirm this man's diagnosis?

  1. splenectomy
  2. Hgb electrophoresis
  3. osmotic fragility
  4. G6PD level
  5. indirect Coombs test

Answer(s): C

Explanation:

Hereditary spherocytosis (HS) is a familial hemolytic disorder with clinical features, ranging from an asymptomatic condition to a fulminant hemolytic anemia. The morphologic hallmark of HS is the microspherocyte, which result from membrane protein defects leading to cytoskeleton instability. Spectrin deficiency leads to loss of erythrocyte surface area, which produces spherical RBCs. Spherocytic RBCs are culled from the circulation by the spleen leading to the development of splenomegaly. Spectrin deficiency and the degree of deficiency correlate with the extent of spherocytosis, the degree of abnormality on osmotic fragility test results, and the severity of hemolysis. Hemolysis primarily is confined to the spleen and, therefore, is extravascular.

Although four abnormalities in red cell membrane proteins have been identified, spectrin deficiency is the most common. Spectrin deficiency results from impaired synthesis, whereas in other instances, it is caused by quantitative or qualitative deficiencies of other proteins that integrate spectrin into the cell membrane. In the absence of these binding proteins, free spectrin is degraded, leading to spectrin deficiency. The major complications are aplastic or megaloblastic crisis, hemolytic crisis, cholecystitis and cholelithiasis, and severe neonatal hemolysis. The classic laboratory features of HS include minimal or no anemia, reticulocytosis, an increased mean corpuscular hemoglobin concentration (MCHC), spherocytes on the peripheral blood smear, hyperbilirubinemia, and abnormal results on the osmotic fragility test. The most sensitive test to help detect HS is the osmotic fragility test performed after incubating RBCs for 1824 hours under sterile conditions at 37°C. Osmoti c fragility measures RBC resistance to hemolysis when exposed to a series of increasingly dilute saline solutions. The sooner hemolysis occurs, the greater the osmotic fragility of the cells.






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