Nelson syndrome
Introduction
Introduction to Nelson syndrome Nelson syndrome is a progressive skin melanin deposition and pituitary tumor after bilateral adrenalectomy for Cushing's syndrome. This syndrome was first reported by Nelson et al in 1958, hence the name Nelson syndrome. basic knowledge Sickness ratio: 0.0001% Susceptible people: no special people Mode of infection: non-infectious Complications: optic atrophy
Cause
Cause of Nelson syndrome
(1) Causes of the disease
Nelson syndrome is due to bilateral adrenalectomy in the treatment of Cushing's syndrome, or residual tissue gradually shrinking, necrosis, loss of function after subtotal resection, it is believed that due to surgery promoted the rapid growth of tumors, the emergence of hormones Secreted disorders and compression symptoms.
(two) pathogenesis
Nelson syndrome is due to bilateral adrenalectomy in the treatment of Cushing's syndrome. Some patients have a small amount of adrenal tissue left by subtotal resection of the adrenal gland, but the residual tissue gradually shrinks, necrosis, and loses function. It is equivalent to a full cut, when the adrenal cortex secretion hormone is too low, the negative feedback effect is weakened, the pituitary gland loses the feedback inhibition of the adrenal cortex hormone, the existing pituitary tumors are progressively enlarged, and a large amount of adrenocorticotropic hormone and melanocytes are secreted. Stimulating hormone (ACTH and -LPH fragments), leading to the formation and development of pituitary tumors, Salassa believes that patients with this disease have tumors hidden in the pituitary gland before surgery, because the surgery promoted the rapid growth of tumors, the emergence of hormone secretion Symptoms and compression symptoms, a scholar found in the autopsy Cushing's syndrome up to 50% of pituitary tumors, most of the tumor is small, can be identified under the microscope.
Prevention
Nelson syndrome prevention
Nelson syndrome can be prevented, and it has been suggested that it can be prevented by radiotherapy outside the body.
Current measures proposed by various scientists to prevent Nelson syndrome include:
1 Because the cause of pituitary Cushing's syndrome in the hypothalamus and pituitary, secrete more ACTH, so it is more inclined to treat the pituitary and hypothalamus, and gradually abandon the total or subtotal resection of the adrenal gland;
2 It is currently considered that the active method for preventing Nelson syndrome is to select transsphenoidal pituitary tumors in patients with Cushing's syndrome with ACTH pituitary microadenomas, which can cure Cushing's syndrome without secondary Nelson syndrome;
3 It has been suggested that patients with Cushing syndrome should be treated with pituitary radiation after adrenalectomy to prevent the occurrence of intrinsic.
Complication
Nelson syndrome complications Complications optic atrophy
Vision loss, drooping eyelids, reduced vision, edema of the optic disc, and optic atrophy.
Symptom
Symptoms of Nelson syndrome Common symptoms Weak vision reduces nausea and bone destruction Osteoporosis
1. The earliest manifestation of early performance is the pigmentation of the skin mucosa. Common parts are: facial, back of the hand, areola, armpit, nail bed and surgical scar, skin, lips, gums, tongue, mouth, vulva, etc., sometimes Longitudinal black streaks are visible on the nails, and the pigmentation is slowly progressively aggravated and does not resolve with the supply of corticosteroids.
2. Sphenoid or saddle tissue compression performance headache, optic nerve compression caused by vision loss, eyelid drooping, visual field reduction, fundus optic disc edema, optic atrophy.
Examine
Nelson syndrome check
1. Laboratory tests showed a significant increase in plasma ACTH concentration, generally exceeding 500 pg/ml, and even as high as 10,000 pg/ml, blood cortisol was significantly reduced, and MSH was significantly elevated.
2. Most of the pathological changes are chromoblastomas, and a few are basophils. The tumors grow faster, oppress the optic nerve and are prone to metastasis.
3. Skull X-ray examination: especially the fault can show the enlargement of the sella, local osteoporosis, bone destruction and the bilateral phenomenon of the bed protrusion. The CT scan of the head can detect the presence or absence of microadenomas in the pituitary fossa.
Diagnosis
Diagnosis and diagnosis of Nelson syndrome
Diagnose based on:
1. Cushing's syndrome after bilateral adrenalectomy.
2. Progressive skin melanin deposition.
3. Skull X-ray photography of the saddle enlargement, local osteoporosis, bone destruction and bilateral phenomenon of the bed.
4. Head CT scan suggests microadenomas in the pituitary fossa.
5. The plasma ACTH level was significantly increased at 100-2200 pmol/L, and MSH was significantly increased.
6. Tumor local compression symptoms headache, fatigue, nausea, vomiting, blurred vision, visual field changes.
Differential diagnosis
1. After the identification of a sufficient amount of corticosteroids with chronic adrenal insufficiency, the pigmentation does not subside.
2. The plasma ACTH value was increased in patients with ectopic Cushing's syndrome. The lysine vasopressin test can be used to identify the plasma ACTH value before and after intramuscular injection of LVP10 international unit. The base value is increased by 300%, and the normal person is only 140%.
3. Patients with skin pigmentation before adrenal surgery should consider the presence of pituitary tumors, and should also consider the ectopic ACTH secretion syndrome caused by pituitary and extra-adrenal cancers.
4. Skin pigmentation after adrenal surgery should consider the following two possibilities: 1 "physiological pigmentation" after bilateral adrenalectomy, mostly occurs within a few months after surgery, self-resolving within 1 to 2 years, very common 2, pituitary tumors occur, skin mucosal pigmentation occurs after a long period of time (2 to 10 years), and is increasing, and those with more than 2 years and extreme fatigue should consider Nelson syndrome.
