Acromegaly — Spade Hands

A 52-year-old man presents to the endocrinology clinic with progressive difficulty wearing his wedding ring and shoes over the past 5 years. On examination, the structure marked **A** in the diagram is noted to be broad and spade-like. His wife reports he snores loudly and has episodes of apnea at night. Serum IGF-1 is elevated at 650 ng/mL (normal <150). Which of the following is the most likely underlying pathology?

A 47-year-old man presents with a 6-year history of progressive coarsening of facial features, increasing ring and shoe sizes, and a doughy handshake. Examination reveals the structure marked **A** — broad, fleshy hands with soft tissue thickening, sausage-shaped digits, deep palmar furrows, and prominent enlarged knuckles. His wife reports he has developed loud snoring with witnessed apneic episodes (AHI 38). Biochemistry shows random GH 28 ng/mL with paradoxical rise to 32 ng/mL after oral glucose tolerance test, and IGF-1 880 ng/mL. MRI shows a 1.8 cm pituitary macroadenoma with suprasellar extension. Which of the following best explains the characteristic appearance of the structure marked **A** in this patient?