All Sample Questions

Hypothyroidism 1

Question

Vignette: A 24-year-old woman presents to her doctor with complaints of fatigue, weight gain, and constipation. On physical examination, her skin is dry, and she has a slow heart rate. Laboratory tests show increased levels of thyroid-stimulating hormone (TSH) and decreased levels of T4. The doctor explains that she has a condition affecting her thyroid gland, which is not producing enough thyroid hormone. Histology of the thyroid gland in this condition would most likely show which of the following?

Choices

A. Decreased number of colloid-filled follicles

B. Increased number of colloid-filled follicles

C. Presence of Reed-Sternberg cells

D. Presence of multinucleated giant cells

E. Presence of granulomas

Answer

B. Increased number of colloid-filled follicles

Explanation

The patient's symptoms and lab findings suggest hypothyroidism, likely Hashimoto's thyroiditis, the most common cause of hypothyroidism in iodine-sufficient areas. Hashimoto's thyroiditis is an autoimmune disease where the body's immune system attacks the thyroid gland, leading to inflammation and impaired thyroid hormone production. Histologically, the thyroid gland in Hashimoto's disease often shows increased numbers of colloid-filled follicles, reflecting the gland's inability to convert the stored hormone (colloid) into active hormone. Over time, lymphocytic infiltration and fibrosis may also occur.

Choice A is incorrect; decreased number of colloid-filled follicles is more indicative of a hyperthyroid state, where the thyroid gland is overactive and rapidly converting stored hormone into active form.

Choices C, D, and E are incorrect as Reed-Sternberg cells are characteristic of Hodgkin's lymphoma, multinucleated giant cells are seen in conditions like tuberculosis and sarcoidosis, and granulomas are characteristic of chronic inflammatory conditions, none of which are relevant to this patient's condition.