MSN 570 Advanced Pathophysiology Final 2024

Correct Answer: A

Rationale: Abrupt withdrawal or discontinuation of prednisone, a corticosteroid, can lead to adrenal crisis. This occurs due to the suppression of the adrenal glands' natural cortisol production caused by prolonged exogenous steroid administration. Adrenal crisis presents with symptoms such as weakness, fatigue, abdominal pain, and hypotension. Hypercortisolism (Cushing syndrome) results from chronic excessive exposure to cortisol, not abrupt withdrawal. ACTH stimulation would be expected in response to low cortisol levels, not as a direct consequence of prednisone withdrawal. Thyroid crisis (thyroid storm) is associated with severe hyperthyroidism and is not directly related to corticosteroid withdrawal.

Correct Answer: C

Rationale: The correct answer is Computed tomography (CT) scan. When screening for lung cancer, CT scans are recommended over chest X-rays due to their higher sensitivity in detecting lung nodules and early-stage cancers. Pulmonary function tests are not used for screening lung cancer but rather to assess lung function. Magnetic resonance imaging is not the preferred imaging modality for routine lung cancer screening, as CT scans are more commonly used.

Correct Answer: A

Rationale: The correct answer is Vitamin B12. Vitamin B12 deficiency can lead to megaloblastic anemia, a condition characterized by the production of abnormally large and immature red blood cells. Lower extremity paresthesias, such as tingling or numbness, are common neurological symptoms associated with vitamin B12 deficiency. Folate deficiency can also cause megaloblastic anemia but is not typically linked to lower extremity paresthesias. Iron deficiency leads to microcytic anemia, not megaloblastic anemia. Vitamin K deficiency is associated with bleeding tendencies, not megaloblastic anemia or paresthesias.

Correct Answer: D

Rationale: The correct answer is Hemangiomas, congenital dermal melanocytosis (i.e., Mongolian spots), and macular stains. These three types of birthmarks are known to fade or regress as the child gets older. Hemangiomas are vascular birthmarks that often shrink and disappear over time. Congenital dermal melanocytosis, commonly known as Mongolian spots, usually fade by adolescence. Macular stains, also called salmon patches, tend to lighten and fade as a child grows. The other choices are incorrect because they do not typically fade or regress with age.

Correct Answer: C

Rationale: Osteosarcoma is an aggressive bone tumor that most commonly arises in the bone marrow of long bones, such as the femur or tibia. Choice A is incorrect as osteosarcoma is not a slow-growing tumor but rather a fast-growing one. Choice B is incorrect as osteosarcoma is not typically solitary but can involve multiple lesions. Choice D is incorrect as osteosarcoma primarily affects the medullary (marrow) cavity of bones, rather than infiltrating the trabeculae in spongy bone and surrounding tissue.