Добавил:
Sekretar
kiopkiopkiop18@yandex.ru
t.me/Prokururor I Вовсе не секретарь, но почту проверяю
Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз:
Предмет:
Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_2690_Библиотеки_им_академика_М_И_Перельмана
.pdf
6.5 Rickets and Osteomalacia 223
https://t.me/medicina_free
recessive nephrolithiasis. Patients with this disorder
commonly present with hypercalciuria, nephrocalcinosis, and renal failure at advanced stage of the disease. Radiological investigations in these patients
include plain radiographs of the bone to show signs of
rickets, and renal ultrasound to detect urinary stones
and medullary calcinosis.
Signs of Rickets on Plain Radiograph
Flaring of the epiphysis.
Bending of the diaphysis of long bones, commonly the tibia
(Fig. 6.5.1 ).
Cupping deformity of the metaphysis due to herniation of the
hypertrophied physis into the metaphysis (Fig. 6.5.2 ). The
metaphyses may also show fi ne bony speculation (Fig. 6.5.3 ).
Looser’s zone fracture ( pseudofractures ) is a very distinctive
feature of osteomalacia, which is characterized by a fracture
through a large osteoid area within the bone. This type of
fracture is rare and tends to occur in the scapula or the pelvis.
Rachitic rosary is swelling of the costo-chondral junction of
the middle ribs.
Osteomalacia presents with signs of osteopenia on
radiographs. It cannot be diff erentiated from osteoporosis
with radiographs alone. History of chronic renal failure is a
helpful clue.
Rickets due to hypophosphatemia are usually associated with
craniosynostosis (e.g., scaphocephaly).
Skull radiographs in patients with rickets show soft skull
bones (craniotabes), fl attening of the skull, hot-cross-bun
skull (caput quadratum), and delayed closure of the
fontanelles.
Hypocalcemic rickets characteristically show hypoplasia of the
dental enamel, whereas abscesses of the teeth occur more
often in rickets due to hypophosphatemia.
Fig. 6.5.1. Anteroposterior plain radiograph of the right knee in
a child with rickets shows mild bowing of the proximal tibial
metaphysis ( arrowheads )
224 Chapter 6 Endocrinology and Metabolism
https://t.me/medicina_free
6.5
Fig. 6.5.2. Anteroposterior plain radiograph of the left knee in a
child with rickets shows focal cupping of the distal femoral
metaphysis ( arrowhead )
Fig. 6.5.3. A plain wrist radiograph of a patient with rickets
shows metaphyseal bony speculations ( arrowhead )
For Further Reading
1. Ramavat LG. Vitamin D defi ciency rickets at birth in Kuwait.
Indian J Pediatr. 1999;66:37–43
2. DeJong AR et al Pseudotumor cerebri and nutritional rick-
ets. Eur J Pediatr. 1985;143:219–20
3. Currarino G. Sagittal synostosis in X-linked hypophos-
phatemic rickets and related diseases. Pediatr Radiol.
2007;37:805–12
4. McBride A et al Vitamin D-resistance rickets (X-linked
hypophosphataemic rickets). Curr Orthop. 2007;21:369–99
5. Mays S et al Skeletal manifestations of rickets in infants and
young children in a historic population from England. Am
J Phys Anthropol. 2006;129:362–74
6. Brickley M et al Evaluation and rickets interpretation of
residual rickets deformities in adults. Int J Osteoarchiol.
2008. doi:10.1002/oa.1007
7. Cheong HI et al Phenotype and genotype of Dent’s disease
in three Korean boys. Pediatr Nephrol. 2005;20:455–9
8. Tosetto E et al Dent’s disease and prevalence of renal stones
in dialysis patients in Northeastern Italy. J Hum Genet.
2006;51:25–30
6.6 Scurvy 225
https://t.me/medicina_free
6.6
S c u r v y
Scurvy is disease that arises due to vitamin C defi ciency. Most cases of scurvy arise due to severe malnutrition, alcoholism, and drug abuse.
Vitamin C (ascorbic acid) functions as a cofactor,
enzyme complement, co-substrate, or a strong antioxidant in a variety of metabolic activities. It provides
electrons needed to reduce molecular oxygen. It also
works as a cofactor for collagen synthesis and norepinephrine synthesis. Vitamin C is present in marine fi sh,
vegetables, and citrus fruits (in high concentrations).
Vitamin C absorption occurs in the small intestine,
and is excreted by the kidneys. The maximum concentration of vitamin C is found in the pituitary gland, leukocytes, brain, adrenals, and the eye.
Patients with scurvy usually present with irritability, limb pain, and tenderness with pseudoparalysis.
Unusual manifestations of scurvy include subdural
and subarachnoid hemorrhage, hematuria, melena,
pleural hemorrhage, and retro-orbital hemorrhage
causing proptosis. Patients improve within 2 days to 1
week from starting vitamin C therapy. Scurvy is often
found in children, and radiographic abnormalities are
rare before 6 months of age.
Signs on Plain Radiograph
Subperiosteal hemorrhage is seen as elevated periosteum from
the bone (Fig. 6.6.1 ).
Wimburger’s sign : sclerotic rim surrounding the epiphysis in
children.
White line of Frankel : dense sclerotic metaphyseal line over the
metaphysis (Fig. 6.6.2 ).
Pelkin’s fracture : metaphyseal avulsion fracture.
Scurvy is a frequent cause of osteoporosis in children
(Fig. 6.6.2 ), and it can predispose to slipped distal femoral
epiphysis due to epiphyseolysis.
Fig. 6.6.1. Anteroposterior left femoral radiograph shows periosteal
hemorrhage in a baby with scurvy seen as radiolucent shadow that
surrounds the distal femur shaft ( arrowheads )
226 Chapter 6 Endocrinology and Metabolism
https://t.me/medicina_free
6.6
For Further Reading
1. Suvarna J et al Hemorrhagic pleural effusion: can it be
scurvy? Indian J Pediatr. 2007;74:1050–1
2. Verma S et al Unilateral proptosis and extradural hematoma in a child with scurvy. Pediatr Radiol. 2007;37:937–9
3. Brickley M et al Skeletal manifestations of infantile scurvy.
Am J Phys Anthropol. 2006;129:163–72
4. Ratageri VH et al Scurvy in infantile tremor syndrome.
Indian J Pediatr. 2005;72:883–4
5. Akikusa JD et al Scurvy: forgotten but not gone. J Paediatr
Child Health. 2003;39:75–7
6. Firth N et al Oral lesions in scurvy. Aust Dent J. 2001;46:
298–300
Fig. 6.6.2. Anteroposterior plain knee radiograph in another
child with scurvy shows dense sclerotic metaphyseal line ( White
line of Frankel ). Notice the diffuse osteoporosis affecting the
entire knee joint
6.7 Fluorosis 227
https://t.me/medicina_free
6.7
Fluorosis
Fluorosis is a clinical condition characterized by excessive ingestion of fl uoride, which causes toxicity and
systemic manifestations that can be disabling.
Fluoride is an element that is found in water, soil, and
air. It results from the combination of the “fl uorine” gas
with different natural elements. Fluoride can be found
in food, seawater, and tea. Each cup of tea may supply
0.3–0.5 mg of fl uoride. The safe daily intake of fl uoride
for an adult is <4 mg/day. Skeletal fl uorosis results from
ingesting fl uoride >10 mg/day for at least 10 years.
Fluorosis classically results from ingestion of water
or food with high fl uoride content in endemic areas.
Fluorosis toxicity may also develop from chronic
intake of sodium fl uoride as a long-standing therapy
for osteoporosis, using tefl on-coated pots, chewing
tobacco, and the overuse of nifl umic acid (nonsteroidal
anti-infl ammatory drug).
Fluoride absorption in the body can be reduced by
taking calcium or magnesium salts. In contrast, phosphate, sulfates and molybdenum increase gastrointestinal absorption of fl uoride and lead to fl uoride toxicity.
Up to 99% of the absorbed fl uoride combines with
the mineralized bones, mostly in the teeth, pelvis, and
vertebrae. Dental fl uorosis deposits mainly in the
enamels and causes brown or black dental pigmentation (Fig. 6.7.1 ). Pitting, chipping, and mottling of the
teeth may also occur.
Patients with fl uorosis often complain from pain in
the joints and back, which is often mistaken with
rheumatic disorders like rheumatoid arthritis and
ankylosing spondylitis. Back stiffness, limb paresthesia, and restricted spine movement are early signs
of fl uorosis. In severe form of back fl uorosis, the vertebral column becomes one continuous column of
bones due to calcifi cation of the paravertebral ligaments, a condition known as “ poker back ” (Figs.
6.7.2 and 6.7.5 ). Development of genu varum, genu
valgum, and kyphosis may occur. Involvement of the
ribs by fl uorosis results in a barrel-shaped chest with
restricted respiratory breathing. Abdominal breathing
becomes the main breathing mechanism is severe
cases.
Fig. 6.7.1. An illustration demonstrates the clinical appearance
of dental fl uorosis
Fig. 6.7.2. An illustration
demonstrates a patient with
poker back due to fl uorosis
228 Chapter 6 Endocrinology and Metabolism
https://t.me/medicina_free
Neurological manifestations of fl uorosis usually are
related to the spinal cord compression due to vertebral
canal stenosis. Patients experience radiculopathy and
diffi culty in walking due to muscle weakness. Cranial
nerve compression may occur when fl uorosis affects
6.7
the skull base foramina.
Some patients develop hyperparathyroidism for
unknown reasons. It is thought that the resistance of
the osteoclastic activity by the sclerotic bones causes
parathyroid hormone over-activity.
Diagnosis is confi rmed by detecting high level of
fl uoride in the urine (main path of fl uoride excretion),
serum, and bone. A 24-h sampling of urine is the most
reliable method for confi rming fl uorosis. The serum
alkaline phosphatase level is usually high.
Signs on Radiographs
Fig. 6.7.3. Anteroposterior pelvis radiograph shows severe systemic fl uorosis with diffuse skeletal sclerosis. Calcifi cation can
be seen affecting even the femoral vessels ( arrowheads )
The axial skeleton is mainly aff ected in the form of sclerosis of
the trabecular bone and thinning of the cortical bone, mostly
aff ecting the vertebrae and the iliac wings (Fig. 6.7.3 ).
Although the pelvis shows sclerosis, the long bones may show
osteopenia. A theory to explain this fi nding states that bones
which accumulate fl uoride are resistant to the osteoclastic
activity of bone remodeling. The hyperparathyroidism
resulting from fl uorosis causes high resorption of the long
bones which do not contain fl uorosis, but not of the sclerotic
axial bones. This may explain the mixed sclerotic–osteoporotic radiological picture seen in fl uorosis.
Subperiosteal new bone formation causes the long bones to
become uneven (Fig. 6.7.4 ).
Ligament calcifi cation is a ver y characteristic sign of fl uorosis,
aff ecting commonly the sacro-tuberous and the petroclinoid
ligaments. Paravertebral ligament calcifi cation causes
vertebral column restriction (Fig. 6.7.5 ).
Prominence of the occipital protuberance with formation of
exostosis occasionally is another minor manifestation.
Fig. 6.7.4. Lateral knee radiograph of the same patient shows
diffuse sclerosis with sclerosis and osteophytes formation of
the quadriceps and patellar tendons insertion at the superior and
the inferior poles of the patella ( arrowheads ). Sclerosis of the
popliteal vessels can be observed too ( arrows )
6.7 Fluorosis 229
https://t.me/medicina_free
For Further Reading
1. Mithal A et al Radiological spectrum of endemic fl uorosis:
relationship with calcium intake. Skelet Radiol. 1993;22:
257–61
2. Lian Z-C et al Osteoporosis – an early radiographic sign of
endemic fl uorosis. Skelet Radiol. 1986;15:350–3
3. Whyte MP et al Skeletal fl uorosis and instant tea. Am J Med.
2005;118:78–82
4. Boillat MA et al Radiological criteria of industrial fl uorosis.
Skelet Radiol. 1980;5:161–5
5. Gupta RK et al Compressive myelopathy in fl uorosis: MRI.
Neuroradiology. 1996;38:338–42
6. Tamer MN et al Osteosclerosis due to endemic fl uorosis. Sci
Total Environ. 2007;373:43–8
Fig. 6.7.5. Anteroposterior plain radiograph of the thoracic
spines of the same patient shows severe vertebral and paravertebral ligaments sclerosis (poker back). Calcifi cation of the supraspinous ligament results in the classical “dagger sign” that is
usually seen in ankylosing spondylitis ( arrowheads )
230 Chapter 6 Endocrinology and Metabolism
https://t.me/medicina_free
6.8
Lead Poisoning (Plumbism)
6.8
Lead poisoning is a clinical condition which arises
either due to direct ingestion of the lead metal compounds (e.g., in water) or by inhalation of lead oxide
fumes. Ingestion of lead compounds is often seen in
children, whereas in adults it is often due to occupational lead inhalation. In children, lead toxicity can be
also due to pica (e.g., dirt eating), inhalation of toxic
fumes, or ingestion of lead-based paints.
The effect of lead poisoning is mainly noticed in the
growing bone. When lead is ingested or inhaled, its
ions deposit on the hydroxyapatite crystal preferentially in the zone of provisional calcifi cation in the
growth plate (physis). Lead mainly inhibits osteoclastic remodeling without affecting the osteoblasts, resulting in an increase in the thickness and the trabeculae at
the metaphyses. This is seen on plain radiographs as a
dense band of bones at the metaphyses of long bones
(dense metaphyseal band sign).
Dense metaphyseal band sign may be seen as a normal variant in healthy children following prolonged
exposure to sunlight. The cause of this phenomenon is
unknown, but it may involve overproduction of endogenous vitamin D. Other causes of dense metaphyseal
band sign include vitamin D toxicity, congenital hypothyroidism, and recovery from scurvy.
Fig. 6.8.1. Anteroposterior plain radiograph of both knees in a
child with lead poisoning shows dense metaphyseal band sign in
the distal femur and the proximal tibia of both knees. The right
proximal fi bular metaphysis shows also the dense metaphyseal
band as a strong indication of lead poisoning
For Further Reading
1. Nagaraj BR et al A rare case of lead poisoning – a case
report. Indian J Radiol Imaging. 2005;15:67–8
2. Raber SA. The dense metaphyseal band sign. Radiology.
1999;211:773–4
3. Blickman JG et al The radiologic “lead band” revisited. AJR.
1986;146:245–7
4. Wiwanitkit V et al Lead intoxication: a summary of the
clinical presentation among Thai patients. BioMetals.
2006;19:345–8
Signs on Radiograph
Dense metaphyseal bands are seen as thick radiopaque bone
at the metaphysis of long bones, especially at the wrists and
knees. All of the other bone structures are normal (Fig. 6.8.1 ).
The presence of a dense metaphyseal band at the proximal
fi bula is a strong indication of lead toxicity.
6.9 Adrenal Glands Abnormalities 231
https://t.me/medicina_free
6.9
Adrenal Glands Abnormalities
The adrenal glands are a pair of retroperitoneal endocrinal glands located above the kidneys. Each gland is
composed of a cortex derived from the mesoderm, and
a medulla derived from the neural crest.
The cortex is composed of three layers: zona fas-
ciculate that secretes cortisol, zona glomerulosa that
secretes aldosterone, and zona reticularis that secretes
androgens. The medulla secretes epinephrine and norepinephrine. Adrenal masses are divided into functioning and nonfunctioning tumors depending on whether
they secrete hormones or not.
Cortical bodies are islands of ectopic chromaffi n
tissues (adrenal cortical tissues) found in the broad
ligament of the uterus, spermatic cord, or epididymis.
A tumor of the ectopic adrenal tissues is called “ para-
ganglioma .” Paragangliomas can be found in the
paraspinal region, pineal gland, and in the urinary
bladder.
On MRI and CT, the thickness of the adrenal limbs
can be compared with the thickness of the adjacent
diaphragmatic crus. The normal glands width should
not exceed that of the adjacent diaphragmatic crus
(normally <5 mm). Both adrenals are found at the level
of T12. The right gland is located posterior to the IVC,
while the left gland is adherent to the left diaphragmatic crus.
The clinical manifestations of CS are attributed to
the chronic exposure to glucocorticoids; however, none
of these symptoms or signs is pathognomonic of the
syndrome. Progressive central obesity is the most common sign of CS. Fat accumulation in the cheeks results
in a “moon” face appearance. Enlarged fat pads that fi ll
the supraclavicular fossae and obscure the clavicles
making the neck appear shortened are characteristic
signs of CS. Up to 5% of patients have increased retroorbital fat content that may cause exophthalmos.
Hypertension, menstrual abnormalities, oligomenorrhea, insomnia, and impaired short-term memory are
well-known manifestations of CS. In obese persons
and patients with CS, renal pelvis lipomatosis may
develop. Renal pelvis lipomatosis is a condition char-
acterized by excess proliferation of the encapsulated
fat cells in the renal pelvis. The proliferated fat causes
mass effect on the intrarenal collecting system, but
rarely leads to symptoms. Replacement lipomatosis of
the kidney is an uncommon extreme form of renal pelvis lipomatosis where the lipomatosis is accompanied
by atrophied or destructed kidney.
Skin manifestations include skin atrophy, easy bruisability, and purple cutaneous striae due to skin stretching.
Hyperpigmentation can be seen in CS due to increased
ACTH release, which induces melanocytes pigment
over-production. When CS is associated with excess
androgens secretion, oily skin, acne, increased libido,
female virilization, and temporal balding may be seen.
Diff erential Diagnoses and Related Diseases
Cushing’s Syndrome
Cushing’s syndrome (CS) is a disease characterized by
multiple systemic manifestations due to chronic exposure to excess glucocorticoids, often due to adrenal
hyperplasia. Cushing disease is a pathological condi-
tion with similar clinical manifestations as CS, but it
arises due to increase glucocorticoid production secondary to an adrenocorticotropic hormone (ACTH)secreting pituitary adenoma. Pseudo-Cushing
syndrome is a term used to describe any condition that
results in distortion of the hypothalamic–pituitary–
adrenal axis.
Nelson’s syndrome is a rare disease characterized by
skin hyperpigmentation after bilateral CS adrenalectomy. The main mechanism of development of this
condition can be explained by hyperactive pituitary
function. The loss of the partial cortisol inhibition on
the pituitary ACTH secretion after adrenalectomy
causes the pituitary to secrete a very large amount of
ACTH that may promote growth of an anterior pituitary adenoma. Serum ACTH levels are excessively
high in patients with Nelson’s syndrome. The prevalence of Nelson’s syndrome after bilateral adrenalectomy ranges from 8 to 29%, with a time interval
between the adrenalectomy and the development of
the disease ranging from 6 months to 24 years.
232 Chapter 6 Endocrinology and Metabolism
https://t.me/medicina_free
Signs on Skeletal Radiographs
Osteoporosis and pathological bone fractures are commonly seen
in chronic cases of CS due to the osteolytic eff ect of glucocorti-
6.9
coids on the bones.
Signs on CT and MRI
Adrenal hyperplasia is checked by detecting bilateral increased
thickness of the adrenal limbs (>5 mm). The adrenal limbs
appear thicker than the adjacent diaphragmatic crus, with the
preservation of the gland’s general shape (Fig. 6.9.1 ).
In Cushing disease and Nelson’s syndrome, anterior pituitary
adenoma is often found (Fig. 6.9.2 ).
Renal pelvis lipomatosis shows proliferation of hypodense fat
at the renal pelvis. Replacement lipomatosis of the kidney is
seen as a fatty mass at the renal pelvis with markedly
atrophied renal parenchyma (Fig. 6.9.3 ).
Conn’s Syndrome (Hyperaldosteronism)
Conn’s syndrome is a clinical pathological condition
characterized by hypertension and hypokalemia due to
excess secretion of aldosterone. Conn’s syndrome
commonly arises due to adrenal adenoma (80%) or
adrenal hyperplasia (20%).
Fig. 6.9.2. Coronal T1W postcontrast MRI of the sellas shows
large pituitary adenoma with inner cystic changes and infi ltration of the left cavernous sinus in a patient with Nelson’s syndrome. The patient had bilateral adrenalectomy in 1994, and he
developed pituitary adenoma in 2006
Fig. 6.9.1. Axial postcontrast CT image of a patient with adrenal hyperplasia shows enlargement of the lateral limb of the
right adrenal gland ( arrowhead )
Fig. 6.9.3. Coronal sequential nonenhanced CT images of
another patient with Cushing’s syndrome (CS) show bilateral
renal pelvis lipomatosis ( arrowheads ), and bilateral adrenal
hyperplasia ( arrows ). Notice how the right adrenal gland is
markedly thickened
Соседние файлы в папке Библиотека им академика М.И. Перельмана