pediatric fibrous osteodystrophy syndrome
Introduction
Introduction to pediatric fibrous dystrophy syndrome Fibrous osteodystrophy syndrome, McCune-Albright syndrome, also known as multiple osteofibrosis (osteitis fibrosadisseminate), fibrous osteodystrophy (osteodystrophiafibrosa), multiple fibrous bone dysplasia, multiple fibrous dysplasia, multiple Fibrous dysplasia, Albright syndrome, Albright-McCune-Stenberg syndrome, brown spot syndrome, bone fibrosis dysplasia-pigmentation syndrome. Its main clinical features are: 1 multiple bone fiber abnormal proliferation, fibrous osteitis, pathological fractures. 2 The skin is pigmented and has a yellow-brown or dark-brown edge with irregular pigmentation spots. The pigmentation is often distributed horizontally with the corresponding skin area of the diseased bone or at the nerve segment. 3 various endocrine abnormalities, more common precocious puberty, hyperthyroidism, giant disease or acromegaly, hyperparathyroidism, Cushing's syndrome, anti-vitamin D rickets. basic knowledge The proportion of illness: 0.0025% Susceptible people: children Mode of infection: non-infectious Complications: optic nerve disease
Cause
Causes of pediatric fibrous dystrophy syndrome
What causes pediatric fibrous dystrophy syndrome?
(1) Causes of the disease
The disease has been reported for the first time in more than 50 years, and its cause is still unknown.
(two) pathogenesis
At present, there are many mechanisms for the endocrine disorders caused by this syndrome, and the following hypotheses are mainly proposed.
1. Central: At the earliest, Albright proposed endocrine disorders caused by thalamic lesions. Some people think that the fibers of the skull base are abnormally hyperplasia, oppressing brain tissue and interfering with hypothalamic function. Warrick et al believe that the endocrine changes are abnormal secretion of hypothalamic release hormone. As a result, some children showed true precocious puberty. Some authors reported that precocious puberty was caused by intracranial tumors, but the above hypothesis could not explain the following three points:
1 Why most precocious puberty is pseudo-precocious.
2 Why most of the precocious puberty X-ray examinations failed to see changes in the skull base.
3 Why women are higher than males.
2. Peripheral endocrine gland target organ function autonomy: Many facts indicate that this disease is accompanied by various endocrine diseases, and there is functional autonomy in its corresponding endocrine target organs, but it cannot explain all the endocrine disorders of this disease, and can not explain endocrine. The relationship between disorders and bone diseases and endocrine disorders caused by central causes.
3.3'5 cyclic adenosine monophosphate (cAMP) and 3'5-phosphate guanosine (cGMP)-mediated mechanism: A large number of facts indicate that this symptom can be associated with pituitary, thyroid, gonad, parathyroid, adrenal gland, etc. Hormones and their activities are regulated by hormone receptors, avian nucleotide regulatory units, adenylate cyclase activation system and protein kinase system. It is believed that endocrine disorders produced by this disease are caused by one of the above various regulatory systems. Due to dysfunction, the subthalamic regulatory polypeptide affects the synthesis and secretion of pituitary hormones through the mediation of cAMP. When the subthalamic regulatory polypeptide binds to receptors on the pituitary cell membrane, the concentration of intracellular cAMP changes. Due to the increase of intracellular cAMP concentration, it can cause the activation of certain protein kinases, thereby promoting the fusion of secretory vesicles and cells, accelerating the secretion of hormones, and controlling the synthesis of proteins in the pituitary, accelerating the pituitary synthesis hormone, using growth hormone. Release of inhibitory hormone stimulates pituitary tissue, intracellular cGMP concentration decreases, cAMP concentration increases, cAMP decreases and cGMP The degree of increase in somatostatin dose.
For skeletal system lesions, it is still believed that it may be related to the abnormal transformation of primitive mesenchymal tissue activity of congenital osteoblasts into fibroblasts. It is also considered that the sensitivity of local bone cells to parathyroid hormone cannot be ruled out, resulting in an increase in bone turnover rate. .
Prevention
Prevention of pediatric fibrous dystrophy syndrome
The cause has not yet been elucidated and there are no definite preventive measures.
Complication
Complications of pediatric fibrous dystrophy syndrome Complications, optic nerve disease
There is a possibility of malignant transformation. The special complication of the bone disease is that the orbital stenosis is caused by abnormal proliferation of bone fibers or hypertrophy of the skull base, and optic nerve damage leads to blindness.
Symptom
Symptoms of pediatric fibrous dystrophy syndrome common symptoms alkaline phosphatase increased multiple nodules urinary phosphorus thyroid enlargement hypophosphatemia pigmentary precocious thyroid gland full moon face hyperparathyroidism hyperactivity
This disease can be afflicted by both men and women. It is more common in women, and it is more common in childhood and in youth. It is mainly manifested as follows.
Endocrine abnormality
(1) precocious puberty: this syndrome can be accompanied by a variety of endocrine abnormalities, of which precocious puberty is more common, precocious puberty is more common with pseudo-precocious puberty, and its clinical manifestations change to the most common developmental order, vaginal bleeding is often sexual The earliest manifestations of precocity, followed by other sexual maturity features.
(2) goiter and hyperthyroidism: the second common disease of this disease, almost one-third of the children have goiter, most of them, clinical, endocrine hormone determination and histological examination, confirmed the presence of hyperthyroidism Histologically, multiple nodular thyroid hyperplasia or gelatinous goiter can also be found in follicular adenoma. The level of TSH in serum is low. For TSH challenge test, TSH often has an inhibitory response.
(3) Giant disease or acromegaly: The clinical manifestations of this disease with giant disease or acromegaly can be atypical, mainly due to the acceleration of bone growth in sexual precocity or the distortion caused by bone lesions in the lower extremities. It can also accelerate bone fusion due to precocious puberty, so when the patient is in his 10s, he developed acromegaly.
(4) Cushing's sign: clinical manifestations are often atypical, no obvious full moon face, skin lines, obesity, but growth delay is often an important clue to diagnose cortisol.
(5) hypophosphatemia rickets: this disease has rickets and hypophosphatemia, alkaline phosphatase increased, but the cause is unknown, it is believed that the kidney is abnormally sensitive to parathyroid hormone, resulting in increased urinary phosphorus excretion, low Phosphemia, elevated alkaline phosphatase, elevated levels of hypercalcemia and plasma parathyroid hormone, strongly suggest hyperparathyroidism.
2. Multi-bone bone fiber abnormal hyperplasia: The bone disease of this disease is a slow progressive process, and the severity of bone disease is not the same. In many cases, pathological fractures, distortions, and self-care difficulties are caused after minor trauma. In a few cases, the lesions can be stable for many years. Some authors have suggested that the bone disease can be relieved by itself after the age of 20, and will the bone lesions caused by this disease be malignant? So far, most of the reported bone diseases do not produce malignant changes, but there are also It is pointed out that for the rapid growth, pain and abnormal increase of alkaline phosphatase in the lesion in the near future, the malignant transformation should be closely monitored.
3. Skin pigmentation: one of the three characteristics of this symptom, the skin pigment is yellowish brown or dark brown ear irregular pigment spots, similar to neurofibroma coffee milk spots, pigmentation appearance time, can be in other characteristics After the onset of sexual symptoms, a small number of patients may have no such signs, pigmented spots appear on the side of the bone lesions, clinically more common in the face, neck, spine and buttocks.
Examine
Examination of pediatric fibrous dystrophy syndrome
Mainly for endocrine hormone determination and histological examination.
1. Histological examination: Histologically, multiple nodular thyroid hyperplasia or gelatinous goiter, or follicular adenoma.
2. Determination of endocrine hormones: The level of TSH in serum is low. For TRH challenge test, TSH often has an inhibitory response, hypercalcemia and elevated plasma parathyroid hormone levels, hypophosphatemia, and elevated alkaline phosphatase. Urinary phosphorus excretion increased, 17-hydroxyl, 17-ketone examination increased.
Should be X-ray, B-ultrasound, electrocardiogram, CT, MRI and other examinations, can be found thyroid enlargement, follicular adenoma, bone age, fracture, limb hypertrophy, skull base hypertrophy caused by optic nerve hole stenosis and other abnormalities.
Diagnosis
Diagnosis and diagnosis of pediatric fibrous dystrophy syndrome
According to typical pigmentation of the skin, precocious puberty, limb bones, skull changes and other endocrine abnormalities, combined with age and sex of onset and related biochemical tests, such as calcium, phosphorus normal, elevated alkaline phosphatase and increased urinary hydroxyammonium excretion With a change in endocrine hormones, a definitive diagnosis can be made.
The symptoms must be differentiated from other endocrine disorders, such as hyperthyroidism, Cushing's sign, idiopathic precocious puberty, Han-Xue-Ke syndrome, other bone tumors, adrenal cortical tumors, ovarian tumors, etc.
