Chemical pathology and Endocrine pathology — OmpathStudy

Chemical pathology and Endocrine pathology — Questions and Answers Complete review bank: 45 questions recovered from all 33 source pages. 1. A 31-year-old woman, who has two healthy children, notes that she has had no menstrual periods for the past 6 months, but she is not pregnant and takes no medications. Within the past week, she has noted some milk production from her breasts. She has been bothered by headaches for the past 3 months. After nearly hitting a bus while changing lanes driving her vehicle, she is concerned with her vision. An optometrist finds her lateral vision to be reduced. On physical examination she is afebrile and normotensive. Which of the following laboratory test findings is most likely to be present in this woman? A. Increased serum cortisol B. Lack of growth hormone suppression C. Increased serum alkaline phosphatase D. Hyperprolactinemia E. Hyponatremia F. Abnormal glucose tolerance test G. Decreased serum TSH Answer: D. The most common mass lesion of the pituitary in an adult is an adenoma that secretes prolactin, and this explains the amenorrhea- galactorrhea that she has been experiencing. A large sellar mass can compress the optic chiasm to produce bitemporal hemianopsia. 2. A 28-year-old woman has had difficulty concentrating at work for the past month. She is constantly getting up and walking around to visit co-workers. She complains that the work area is too hot. She seems nervous and often spills her coffee. She has been eating more but has lost 5 kg in the past 2 months. On physical examination her temperature is 37.5°C, pulse 108/minute, respiratory rate 24/minute, and blood pressure 145/85 mm Hg. Which of the following laboratory findings is most likely to be present in this woman? A. Decreased catecholamines B. Decreased iodine uptake C. Decreased plasma insulin D. Decreased TSH E. Increased ACTH F. Increased calcitonin Answer: D. She has Graves disease with hyperthyroidism. There are both thyroid-stimulating immunoglobulins (TSI) and thyroid growth-stimulating immunoglobulins (TGI) in Graves disease. The amount of thyroid hormone production goes up, suppressing TSH secretion from the pituitary. The diffusely enlarged thyroid gland is double to triple in size, which is still difficult to appreciate on physical examination. 3. A 19-year-old previously healthy woman has had a mild pharyngitis followed by a high fever over the past 24 hours. When seen in the emergency room, her skin now shows extensive areas of purpura. Vital signs include temperature 39°C, pulse rate 102/minute, respiratory rate 26/minute, and blood pressure 80/55 mm Hg. Laboratory studies show a serum sodium of 115 mmol/L, potassium 5.3 mmol/L, chloride 92 mmol/L, CO2 22 mmol/L, glucose 42 mg/dL, and creatinine 1.1 mg/dL. Which of the following is the most likely diagnosis? A. Idiopathic adrenalitis B. Disseminated tuberculosis C. Reactive systemic amyloidosis D. Sheehan syndrome E. Meningococcemia F. Hemochromatosis Answer: E. This is acute adrenal insufficiency marked by hyponatremia, hyperkalemia, and hypoglycemia. Infection with Neisseria meningitidis can produce the Waterhouse-Friderischsen syndrome, complicated by disseminated intravascular coagulopathy. 4. A 40-year-old woman has noted enlargement of her anterior neck region over the past 8 months. On physical examination her vital signs include T 36.8°C, P 64/minute, RR 16/minute, and BP 155/105 mm Hg. There is diffuse, symmetrical thyroid enlargement without tenderness. A chest radiograph is normal. Fine needle aspiration of the thyroid yields cells consistent with a neoplasm. Laboratory studies show that she is euthyroid, but her serum ionized calcium is elevated. She is taken to surgery and frozen sections of several thyroid masses show a malignant neoplasm composed of polygonal cells in nests. A thyroidectomy is performed. Immunostaining for calcitonin of the permanent sections is positive, and the neoplasm has an amyloid stroma with Congo red staining. Which of the following neoplasms is she most likely to have? A. Anaplastic carcinoma B. Medullary carcinoma C. Papillary thyroid carcinoma D. Metastatic renal cell carcinoma E. Parathyroid carcinoma F. Follicular carcinoma Answer: B. She has MEN IIa, with medullary thyroid carcinomas (often multiple when familial), parathyroid hyperplasia, and pheochromocytoma. 5. A 37-year-old man experiences abdominal pain, nausea, and constipation for the past 3 days. On physical examination he has no palpable abdominal masses and bowel sounds are present. His lungs are clear to auscultation. He has a heart rate of 80/min with an irregular rhythm. An electrocardiogram demonstrates a shortened QT(corrected) interval and a prolonged PR interval. He has a stool positive for occult blood. Upper GI endoscopy reveals multiple 1 cm diameter shallow ulcerations of the gastric antrum. Which of the following laboratory test findings is most likely to be present in this man? A. Thyroid peroxidase antibody of 4 IU/mL