A 44-year-old man with marked features of acromegaly presents for transsphenoidal hypophysectomy. The patient reports increasing shoe size, glove size, and worsening sleep apnea. Magnetic resonance imaging revealed a pituitary mass. Laboratory findings are within normal limits with the exception of serum glucose, which is 170 mg/dL. The patient does not have any allergies and does not take medications at home. Past surgical history includes carpal tunnel release bilaterally. He denies other medical problems.
What is acromegaly?
Acromegaly was previously considered a rare disease. However, more recent European studies and improved screening suggest that clinically significant pituitary adenomas occur in 1 per 1064 people. Growth hormone (GH)–secreting tumors of the pituitary constitute at least 10% of benign pituitary tumors. The pituitary gland is anatomically and functionally separated into the anterior pituitary (adenohypophysis) and posterior pituitary (neurohypophysis). In children, GH-secreting tumors cause gigantism; acromegaly occurs in adults whose epiphyses have fused. Acromegaly is most common in patients 20–60 years old, with equal distribution between the genders. The diagnosis is generally made 10–15 years after the onset of pathologic GH secretion. There is a twofold to fourfold increase in mortality versus the general population. If untreated, 50% of patients with acromegaly die before age 50 years. The most common cause of death is cardiac and may be the result of hypertension, coronary artery disease, compensatory hypertrophy as a result of generalized somatomegaly, or the direct effects of GH on the heart.
Acromegaly results from excess secretion of GH and subsequent elevation of circulating and locally produced insulin-like growth factor I (IGF-I). GH and IGF-I levels are controlled via several interactions rather than stimulating growth directly. GH induces the release of IGF-I, which promotes DNA, RNA, and protein synthesis as well as cell and tissue growth.
What symptoms are typical of acromegaly?
The structural changes of acromegaly cause chronic pain and discomfort. These symptoms reduce quality of life and life expectancy. Changes include skeletal overgrowth deformities (particularly of the hands, feet, and face), cardiovascular disease (hypertension, enlarged heart), arthropathy, neuropathy, and respiratory obstruction ( Boxes 19-1 and 19-2 ).
Facial bones—large bulbous nose
Impaired mobility of cricoarytenoid joints
Compression of recurrent laryngeal nerves
Limitation in head and neck mobility
Development or exacerbation of sleep apnea
Enlarged hands and feet
Distortion of facial features
Soft tissue overgrowth
Enlarged lips, tongue, epiglottis, and vocal cords
Connective tissue overgrowth
Recurrent laryngeal nerve paralysis
Carpal tunnel syndrome
Skeletal muscle weakness