A patient presents with a painless, slowly enlarging mass in the right neck, just above the clavicle. Fine-needle aspiration cytology reveals clusters of polygonal cells with clear cytoplasm and centrally located nuclei. Which of the following conditions is most likely responsible for this presentation?

Correct Answer: A

Rationale: The described presentation of a painless, slowly enlarging mass in the right neck just above the clavicle, along with the cytology findings of clusters of polygonal cells with clear cytoplasm and centrally located nuclei, is classic for parathyroid adenoma. Parathyroid adenomas are benign tumors arising from one of the parathyroid glands, which are typically located in the neck region close to the thyroid gland. The clear cytoplasm and centrally located nuclei of the cells are characteristic histological features of parathyroid adenomas. This condition can often lead to hyperparathyroidism, characterized by increased levels of parathyroid hormone (PTH) and hypercalcemia. Treatment involves surgical removal of the adenoma.

Correct Answer: A

Rationale: The clinical presentation described is highly suggestive of acute angle-closure glaucoma. This condition typically presents with sudden-onset severe eye pain, headache, nausea, and vomiting. The red eye, steamy cornea (due to corneal edema), and mid-dilated, non-reactive pupil (from the unopposed force of the dilator muscle) are classic findings in acute angle-closure glaucoma. The increase in intraocular pressure compromises blood flow to the eye, leading to symptoms of blurred vision and possible visual loss. Immediate management usually involves lowering intraocular pressure with medications or surgical intervention to prevent vision loss. Central retinal artery occlusion, optic neuritis, and corneal ulcer typically present with different clinical features and are not consistent with the described presentation.

Correct Answer: B

Rationale: Enamel hypoplasia is a common oral manifestation of celiac disease characterized by defects in the enamel of the teeth. These defects can appear as horizontal or vertical grooves on the teeth. Enamel hypoplasia is caused by disruptions in the formation of enamel during tooth development, leading to thin enamel or localized pitting. It can affect the appearance and strength of the teeth, making them more prone to sensitivity and breakdown. In individuals with celiac disease, enamel hypoplasia may occur due to malabsorption of essential nutrients like calcium and vitamin D. Therefore, when observing oral manifestations such as enamel defects with grooves, it is important to consider the possibility of celiac disease as an underlying cause.

Correct Answer: B

Rationale: The stomach is the organ responsible for the mechanical and chemical digestion of food. When food enters the stomach, it is mixed with stomach acid and enzymes to break down the food into smaller particles. This process helps prepare the food for further digestion and absorption of nutrients. The stomach also plays a key role in the absorption of some nutrients, such as certain vitamins and minerals. Additionally, the stomach's muscular contractions help mix the food with digestive enzymes and propel the partially digested food into the small intestine for further processing and absorption. The liver, pancreas, and large intestine have vital functions in the digestive system, but the stomach is the primary organ responsible for the initial digestion and absorption of nutrients.

Correct Answer: B

Rationale: The stomach is responsible for producing hydrochloric acid and intrinsic factor. Hydrochloric acid helps in the breakdown of proteins during digestion, while intrinsic factor aids in the absorption of vitamin B12 in the small intestine. These two components are crucial for the proper functioning of the digestive system, particularly in breaking down food and absorbing essential nutrients. The liver is involved in bile production, the pancreas in the production of digestive enzymes, and the small intestine in nutrient absorption, but the specific functions related to hydrochloric acid and intrinsic factor are primarily attributed to the stomach.