Prominent forehead and cheekbones
Introduction
Introduction The clinical symptoms of acromegaly often manifest as forehead and tibia. Acromegaly is a hyperproliferative disease of the skin and bone caused by excessive growth hormone secretion caused by hyperplasia or tumor.
Cause
Cause
(1) Causes of the disease
The disease is caused by excessive secretion of growth hormone in the pituitary gland caused by pituitary tumors or other causes. GH secretion has a significant circadian rhythm, and the peak of adult secretion is mostly at night. GH mainly acts to promote the growth of bone tissue, muscle, connective tissue and viscera, promote DNA and RNA synthesis, fight insulin to promote sodium retention, and stimulate the body to secrete some peptides, such as growth mediators. The effect of GH on glucose metabolism is insulin-like and anti-insulin-like. The former occurs earlier and the latter occurs later. GH also has a direct effect on islet B cells. About one-fourth of patients can have diabetes at the same time. Somatomedin (SM) is derived from the liver. It can increase the growth of cartilage through the influence of DNA and RNA protein synthesis. The growth factors include A, B and C, which can mediate the growth effect of GH on bone. . Interleukin A (SmA) stimulates collagen and non-collagen synthesis, and interleukin C (SmC) stimulates collagen synthesis in osteoblasts. BGP acts as a result of GH acting through SmA.
Too much GH can accelerate bone formation and maturation and promote bone growth. Bone remodeling increases and bone turnover is accelerated. Pituitary dwarfism causes bone growth and development to be stopped or delayed due to GH deficiency. In the human body, GH can increase intestinal calcium absorption, bone formation and bone mineralization, and increase bone mass. In vitro, it cannot directly stimulate bone matrix formation. Interleukin has a growth-promoting effect on various tissues, can mediate the effect of GH on bone growth, and promote growth of both bone and cartilage. GH can change the circadian rhythm of serum phosphorus, increase blood phosphorus, increase TRP, and change the maximum reabsorption/glomerular filtration rate (TMP/GFR) of renal phosphorus, further increasing blood phosphorus. GH promotes an increase in TRP and inhibits PTH secretion, thereby lowering PTH levels and also increasing blood phosphorus.
When the patient's diet has insufficient calcium, it may have a negative calcium balance, causing osteoporosis. After increasing the dietary calcium intake, it can be converted to a positive calcium balance. As the bone turnover increases, the GFR increases and the TRGa decreases, which promotes the increase of high urinary calcium and further increases bone lesions. GH can stimulate subperiosteal bone formation, and the epithelial fibroblasts differentiate into primitive osteoblasts, promote new bone formation, and the original normal epithelial activity is activated again. The cartilage of the epiphyseal plate is active and promotes osteophytes. Cartilage hyperplasia. GH can also promote the connective tissue changes in the joints, the joint capsules become thicker, the fat pad is fibrotic, and the fibrous tissue of the joints of bone and cartilage and periosteum proliferates. Osteoporosis in acromegaly is different from bone loss in other osteoporosis, but increases cortical bone formation with increased calcium conversion rate, increased bone mass, bone hyperplasia and osteoporosis, or local Such as saddle back bone absorption, saddle bottom bone absorption and other abnormalities.
(two) pathogenesis
Because the pituitary gland excessively secretes growth hormone, it can cause giant disease before the bones are closed in prepuberty, while adults with closed bones can cause enlargement of the hands, feet, soft tissues, internal organs and some flat bones. The clinical manifestation is Acromegaly.
Examine
an examination
Related inspection
Blood routine maxillofacial five-score CT examination
Acromegaly: slow onset, headache, vision loss, visual field defect, special face: enlarged jaw, forehead and tibia, thick lip, large nose, large tongue, rough face, thick skin; hand and foot Hypertrophy.
Diagnosis
Differential diagnosis
Differential diagnosis of the forehead and humerus protrusion:
1. Acromegaly: The disease is familial or constitutional. It has a change in appearance since childhood, and its appearance is similar to that of acromegaly, but to a lesser extent. No abnormalities are found in the examination, and plasma GH levels are not high. X-ray examination of the saddle does not expand, BMC is normal.
2. There is no testicular giant disease: tall body, gonad atrophy, distance between fingers exceeds the length of the body, osteophyte closure is late, bone age is delayed, X-ray film shows small saddle, bone structure is smaller than giant disease and acromegaly. Gonadal function disappeared, sex hormone levels were mutated, GH levels were not high, and other biochemical tests and laboratory tests such as acromegaly were found.
3. Hand and foot skin skeletal hypertrophy: Most of the patients are male youth, the shape is similar to acromegaly, but the endocrine students with acromegaly have metabolic disorders. The blood GH level is normal, the saddle does not enlarge, the skull is not large, and the bone changes are not obvious.
4. The lumbar vertebrae, the sella and the hand and foot X-ray examination of the forehead and humerus have special performance. The GH measurement indicates that GH is excessively secreted, so it can be differentiated from ankylosing spondylitis. Late lesions are similar to osteoarthritis caused by other causes and are difficult to identify.
Acromegaly: slow onset, headache, vision loss, visual field defect, special face: enlarged jaw, forehead and tibia, thick lip, large nose, large tongue, rough face, thick skin; hand and foot Hypertrophy.
