What skin lesion is described as an elevated, thin-walled lesion containing clear fluid?

Choice A reason: Graves’ disease, a form of hyperthyroidism, does not typically cause decreased calcium. It may lead to hypercalcemia due to increased bone resorption from elevated thyroid hormone levels, which enhance osteoclast activity, making decreased calcium an incorrect laboratory finding for this condition.

Choice B reason: Graves’ disease is characterized by increased thyroid hormone production, including elevated T4 due to autoimmune stimulation of the thyroid. Decreased T4 is associated with hypothyroidism, not hyperthyroidism, making this choice incorrect as it contradicts the pathophysiology of Graves’ disease.

Choice C reason: Increased TSH is seen in primary hypothyroidism, where the thyroid is underactive. In Graves’ disease, TSH is typically decreased due to negative feedback from elevated thyroid hormones (T3 and T4), making this choice incorrect for the expected laboratory profile.

Choice D reason: Graves’ disease causes hyperthyroidism, with increased production of thyroid hormones, including T3, due to autoantibodies stimulating TSH receptors. Elevated T3 levels drive metabolic symptoms like weight loss and tachycardia, making this the correct laboratory finding for Graves’ disease.

Choice A reason: Abnormal tau proteins contribute to Alzheimer’s, forming neurofibrillary tangles, but damage is not limited to the frontal lobe. The hippocampus and other regions are primarily affected, leading to memory loss. This choice is too specific and incomplete, making it incorrect.

Choice B reason: Damaged blood vessels interrupting brain blood flow describe vascular dementia, not Alzheimer’s. Alzheimer’s involves neuronal degeneration from protein accumulation, not primarily vascular pathology, although vascular factors may contribute, making this choice incorrect for Alzheimer’s pathophysiology.

Choice C reason: Repeated traumatic brain injuries cause chronic traumatic encephalopathy, not Alzheimer’s. While trauma may increase Alzheimer’s risk, the primary pathology involves amyloid and tau proteins, not trauma-induced encephalopathy, making this choice incorrect for the disease’s core pathophysiology.

Choice D reason: Alzheimer’s disease is characterized by amyloid-beta plaques and tau protein tangles, which disrupt neuronal function, particularly in the hippocampus, leading to memory impairment. These protein aggregates cause synaptic loss and neurodegeneration, accurately describing the disease’s pathophysiology, making this the correct choice.