What is the most common diagnosis for a patient presenting with enlarged fingers and coarse facial features?

Enlarged fingers and coarse facial features are hallmark signs of acromegaly, a condition that arises from excess growth hormone usually due to a pituitary adenoma. This excess growth hormone leads to the abnormal growth of bones and soft tissues, resulting in the characteristic physical changes. In acromegaly, patients often present with not only enlarged fingers but also changes in facial appearance, such as a protruding jaw and enlarged nasal bones.

In contrast, the other conditions listed do not typically present with these specific symptoms. Cushing's syndrome may lead to facial rounding and central obesity but generally doesn’t cause the enlargement of fingers or coarse features characteristic of acromegaly. Hypothyroidism can result in some features like dry skin and hair loss, but not the specific bone growth changes. Marfan syndrome is primarily associated with skeletal abnormalities, but it usually presents with long, slender fingers and a tall stature rather than the enlarged features seen in acromegaly. Therefore, the presence of enlarged fingers and coarse facial features strongly indicates acromegaly as the most common diagnosis.