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The frst genetic mutation responsible for the cause of most common form of thumb duplication purchase atacand on line. Soft tissue bulk on certain types of radial polydactyly with triphalangeal thumb both partners is less than normal order 16 mg atacand mastercard. The metacarpal head is often and for triphalangeal thumb alone has been localized on chro- broad with bifd cheap atacand 16mg line, asymmetric condyles. When the proximal diver- underlying skeleton may often gives clues to the associated gence is great the distal portions deviate toward one another. They present a nail which may be either fused tendons onto the side of the distal phalanges instead of the with a longitudinal ridge or have a smooth conjoined surface. With rebalancing during surgical correction the ab- low soft tissue in the hyponychium. Pulp surfaces are often fat normal joint surfaces will not necessarily correct themselves but stable. The pollex abductus anomaly in which there radial side attach to the radial thumb. There is often a very is a soft tissue connection between the extrinsic fexor and thick fbrous band over the adductor pollicis aponeurosis. In addition, the origin of the extrinsic fexor (fexor thumbs are always smaller than normal and one thumb may pollicis longus) is often anomalous with a very limited excur- be triphalangeal with an extra phalanx (. Because the meta- the anatomic variations become greater and more compli- carpals are small and the phalangeal segments deviated, these cated. A rudimentary or fouting thumb may be attached to thumbs are shorter and smaller than normal. All degrees of intrinsic muscle anomalous attachments In contrast to isolated thumb polydactyly, the association are seen; often the adductor pollicis may have components of triphalangeal components (i. Congenital malformations of the hand: Indica- tions, operative treatment and results. Clinical and genetic studies on 12 preaxial polydactyly families and refnement of the localization of the gene responsible to a 1. Pre-axial Polydactylie in fünf Generationen einer on the far right in which the metacarpal head of the ulnar thumb is not schwedischen Sippe. Classifcation and treatment of triphalangeal radial thumb with a phalangeal deviation toward the ulnar partner (With thumbs. Approximately half of the triphalangeal thumbs recorded in Shoen and Upton’s registry are associated with thumb polydactyly . The triphalangeal rays can be either balanced or unbalanced and are always longer than normal. Presentation Most symptoms occur between 20 and 30 years of age through the onset of diabetes, and visual, skin, and hair manifestations. Metastatic subcutaneous calcifcations and atherosclerosis are also common  along with short stature. Upper extremity Digital hypoplasia, radial polydactyly, soft tissue calcifcation, and osteoporosis were all reported. Observa- acteristically rests tightly fexed against the palm of the hand tion of the resting posture of the thumb and the position of its beneath the four digits (. Newborns normally three joints will help localize the specifc anatomic problem tend to maintain the thumb beneath the fexed fngers for in many cases (. When extension is lacking at all three often bilateral than unilateral  and is seen in males twice thumb joints with added defciency of the abductor pollicis as often as females . Congenital clasped thumb is not very longus tendon, as in the typical clasped thumb, the latter common and typically the result of hypoplasia or absence of will extend across the entire palm and rests at the base of the a portion of the extensor musculotendinous unit. The contribution of the intrinsic thenar muscula- skin defciencies both palmar and frst web space, collateral ture on either side of the thumb must also be considered as Fig. Lower extremity anomalies may also be present Two classifcation systems have been described with clini- such as clubfeet. The spastic thumb-in-palm posture and all space contracture, volar skin shortage, and thenar muscle ab- the secondary problems related to a long-standing contracture normality. Congenital digital fexion defor- mity is also caused by defciency of the extensor mecha- nism of the fngers. This is typically present in Freeman-Sheldon syndrome, arthrogryposis multiplex congenita, and the congenital ulnar drift deformity “wind- blown” hand. Note the wrist has been fused to correct severe fexion defor- a patient with cerebral palsy with a common thumb presentation of ad- mity. The thumb extensors are intrinsic muscles, most often the frst dorsal interosseous and adductor not absent as in clasp thumb but rather attenuated and weak References Associated Syndromes 1. Congenital clasped thumb (congenital Stuve-Wiedemann syndrome fexion-adduction deformity of the thumb): a syndrome, not a spe- cifc entity. Characteristics of patients with congenital clasped thumb: a prospective study of 40 pa- Waardenburg syndrome tients with the results of treatment. Complete annular and partial oblique pulley re- lease for pediatric locked trigger thumb. Treatment of spastic thumb-in-palm deformity: A modifed extensor pollicis longus tendon rerouting. X-linked mental retardation associated with Etiology The condition is caused by mutation in the gene bilateral clasp thumb anomaly. General musculoskeletal Generalized muscle spasticity but affecting more severely those of the lower extremity. However, index fnger contracture was reported  along with rounded shoulders and internally ro- tated arms . In addition, camptodactyly involving one or more of the ulnar three digits on either or both hands may be seen (. Stüve-Wiedemann syndrome and re- Hallmarks Hyperthermia, respiratory abnormalities, short lated bent bone dysplasias. Clinical ho- a frst-cousin male with congenital bowing of the long bones mogeneity of the Stuve-Wiedemann syndrome and overlap with the and digital contractures. Stuve-Wiedemann syn- drome: a skeletal dysplasia characterized by bowed long bones. Ul- Etiology The condition results from autosomal recessive mu- trasound Obstet Gynecol. General musculoskeletal Postnatal short stature is common [6,7] along with long bone dysplasia, which leads to curvature or bowing of bones . Multiple muscle and joint contrac- tures,  muscle hypotonia, and osteoporosis may be present. Upper extremity Camptodactyly seems to be the most com- mon hand anomaly followed by multiple digital fexion defor- mity of all the small joints in the hand including the thumb. Frontal bossing, midface hypoplasia, short nose, low-set ears, and micrognathia are also seen. Systemic Cardiac anomalies mostly in the form of premature closure of the ductus arteriosus.
One consequence of excessive menstrual loss is iron de- multiple enzymes in the steroidogenic pathway purchase discount atacand, and in- ficiency anaemia discount 4mg atacand with visa. In the Western world purchase atacand uk, menorrhagia is the creasing plasma free testosterone concentrations. Medroxyprogesterone causes the decidualisation of endo- Medical treatment of menorrhagia is either non-hormonal metrial tissue, with eventual atrophy. As there is no hormonal defect, the use Adverse effects occur at low (20–30 mg/day) or high of hormonal therapy does not correct an underlying disor- (100 mg/day) dose, and include abnormal uterine bleed- der but merely imposes an external control of the cycle. For ing, nausea, breast tenderness, fluid retention and depres- many women, cycle control is as important an issue as the sion. Gestrinone 5–10 mg/week is an antiprogestational ste- The two main first-line treatments for menorrhagia asso- roid that causes a decline in the concentrations of oestrogen ciated with ovulatory cycles are non-hormonal, namely and progesterone receptors, and a 50% decline in plasma tranexamic acid (an antifibrinolytic) and a non-steroidal estradiol concentrations. The effectiveness of oestrogen and a progestogen induces a hormonal pseudo- these treatments has been shown in randomised trials pregnancy. The oral contraceptive is used either continu- and reported in systematic reviews of treatment. Tranexa- ously or cyclically (21 active pills followed by 7 days of mic acid reduces menstrual loss by about a half and placebo). Both have the advantage continuous administration is advantageous for women of being taken only during menstruation itself and are par- with dysmenorrhoea. They are inish the secretion of follicle stimulating hormone and also of value in treating excessive menstrual blood loss as- luteinising hormone, resulting in hypogonadotrophic sociated with the use of non-hormonal intrauterine contra- hypogonadism, endometrial atrophy and amenorrhoea. Progestogens are effective only when unwanted effects are the menopausal-type symptoms of 611 Section | 8 | Endocrine system, metabolic conditions hypo-oestrogenism (such as transient vaginal bleeding, effect is on the blood pressure, which may fall if an over- hot flushes, vaginal dryness) and can be prevented by dose is given. The association of oxytocin with neonatal jaundice appears to be due to increased erythrocyte fragility Premenstrual tension syndrome may be due to an causing haemolysis. Drugs are not necessarily the preferred Ergometrine is used to contract the uterus. The uterus Cyclical breast pain or mastalgia, when severe, may re- is stimulated at all times, but is much more sensitive in late spond to continuous use of gamolenic acid (Efamast) by pregnancy (see also ergotamine, p. In moderate doses, oxytocin produces slow ducing cellular uptake of prolactin and ovarian hormones. Prostaglandins Oxytocics Oxytocin is a peptide hormone of the posterior pituitary (For a general account of the prostaglandins see Ch. It stimulates the contractions of the pregnant uterus, which becomes much more sensitive to iThat term. Patients tion on collagen) and have a powerful oxytocic effect include: with posterior pituitary disease (diabetes insipidus) can go into labour normally. The only other clinically important amniotic injection, by vaginal tablet, or intracervical gel, 612 Hypothalamic, pituitary and sex hormones Chapter | 38 | by intravenous infusion or by mouth. Their safe and effec- • Oxytocin should not be started for 6 h following tive use (including choice of route) requires special skill. Adverse effects include vomiting, diarrhoea, headache, py- • When used to induce labour, the recommended rexia and local tissue reaction. Carboprost (prostaglandin F2 analogue) is used for post- Prevention and treatment of uterine partum haemorrhage (resistant to ergometrine and oxyto- cin) for its oxytocin action. Adverse haemorrhage effects include hypertension, asthma and pulmonary Bleeding due to incomplete abortion can be controlled oedema. Induction of abortion For the routine management of the third stage of labour ergometrine 500 micrograms with oxytocin 5 units (Synto- Gemeprost, administered vaginally as pessaries, is the pre- metrine 1 mL) is given by intramuscular injection on deliv- ferred prostaglandin for the medical induction of late ther- ery of the anterior shoulder or, at the latest, immediately apeutic abortion. In pre-eclampsia, oxytocin may before surgical abortion, particularly in primigravida. These regimens prostol by mouth or by vaginal administration, or geme- are also used for the treatment of postpartum haemorrhage. Uterine relaxants b2-Adrenoceptor agonists relax the uterus and are given by Induction and augmentation of i. Their use is complicated by the expected cardiovascular effects, in- Oxytocin is administered by slow intravenous infusion as cluding tachycardia, hypotension. Less easy to explain, below, usually in conjunction with amniotomy, and dino- but more devastating on occasion to the patient, is severe prostone by vaginal tablets, pessaries and vaginal gels. It lence has recommended that: is important to administer the b agonist with minimum 2 • Dinoprostone is preferable to oxytocin for induction of fluid volume using a syringe pump with 5% dextrose labour in women with intact membranes, regardless of (not saline) as diluent, and to monitor the patient closely parity or cervical favourability. Hormone suppression test in the diagnosis that they are better than cheaper replacement therapy and breast of Cushing’s syndrome. The nutritional aspects, physiological function, prompted a number of clinical trials examining the poten- sources, daily requirements and deficiency syndromes tial benefit of vitamin supplementation in the prevention (primary and secondary) are to be found in any textbook of cancer, cardiovascular disease and other common dis- of medicine. Vitamins fall into two groups: Humans cannot synthesise vitamins in the body except • Water-soluble vitamins: the B group and vitamin C. Vitamin A is a generic term embracing substances having Vitamin deficiencies are commonly multiple, and com- the biological actions of retinol and related substances plex clinical pictures occur. The principal functions of retinol are to: and multivitamin preparations available to provide • sustain normal epithelia prophylaxis and therapy. An- orexia, skin lesions, hair loss, hepatosplenomegaly, papil- Psoriasis loedema, bleeding and general malaise also occur. Tazorotene, a topical retinoid, is effective in the treatment of Vitamin A accumulates in liver and fat, and effects take chronic stable plaque psoriasis. Chronic overdose also makes the biolog- making it unsuitable for the treatment of inflammatory ical membranes and the outer layer of the skin more liable forms of psoriasis. Vitamin A and its derivatives are terato- ative (t½ 48 h) that is used orally for severe psoriasis. Dose genic at pharmacological doses (for precautions, see use range 25 mg alternate days – 50 mg daily (see p. It is also effec- A number of widely differing substances are now, for con- tive for preventing second tumours in patients following venience, classed as the ‘vitamin B complex’. Those used for treatment for primary squamous cell carcinoma of the head pharmacotherapy include the following: and neck. Deficiency is associated with three distinct conditions: Wernicke–Korsakoff syndrome, beriberi, and Acute promyelocytic leukaemia Leigh’s syndrome. It is given orally for nutri- Tretinoin can be used to induce remission in conjunction tional purposes, but intravenously in serious emergencies, with chemotherapy in acute promyelocytic leukaemia, a e. Initially, it proved remarkably successful, but the high doses given caused the fatal ‘differentiation syn- Cobalamins (B12). More hydralazine and penicillamine; pyridoxine 10 mg/day pre- frequent doses are required for treatment of xerophthalmia. Vitamin A supplementation at pharma- has found use for a variety of conditions including premen- cological doses is standard for patients with cystic fibrosis. This can result in chronic toxicity and serum retinol levels Niacin (nicotinic acid, B3) is converted to nicotinamide, should be monitored. Nico- Acute toxicity occurs in adults with a single dose of more tinamide is used for nutritional purposes.
Three-month mortality is tes may exhibit rapid weight loss order atacand 8mg visa, which should not exceed high buy 4 mg atacand fast delivery. Patients lose weight if the urinary sodium excretion exceeds intake; those who do not respond despite a high Hepatic encephalopathy urinary sodium are almost certainly receiving additional dietary sodium (sometimes iatrogenic discount atacand online american express, e. Infection, gastrointestinal bleeding, injudicious use of sed- Unwanted effects of diuretic use are very common; in addi- atives and diuretics can precipitate hepatic encephalopathy tion to electrolyte disturbances and renal impairment, in cirrhosis. The pathophysiology is complex but ammonia cramps are unpleasant and if spironolactone causes painful is a key player. Diagnosis is confirmed by elevated plasma gynaecomastia, amiloride is an alternative (10–40 mg/day). Ammonia is 550 Liver and biliary tract Chapter | 34 | beneficial effects that usually fall short of cure. Recent clin- Splanchnic vasodilatation ical trials show sorafenib extends life by a few months in pa- tients with compensated cirrhosis, but with significant toxicity. The presentations include jaundice with ill-health, relapsing/remitting jaundice and, less commonly, subacute liver failure. A third of patients have cirrhosis at presenta- tion and untreated cases progress to cirrhosis. Ritux- Ascites syndrome imab, to deplete B cells, may have a role in this unusual scenario but data are preliminary. The majority of patients improve substantially with corti- costeroids and a fall in serum bilirubin occurs usually within derived from the action of colonic urease-containing bacte- 2 weeks. Azathioprine (1 mg/kg daily)should be introduced ria and normally undergoes hepatic extraction from portal when jaundice improves and is an effective steroid-sparing blood, but with portal/systemic shunting and impaired he- agent. In the long term corticosteroid doses should be ad- patic metabolism, it reaches high systemic concentrations, justed according to liver function. Lactulose acts as an osmotic laxative to expedite clearance Remission can be maintained in the first 2 years by azathio- of potentially toxic substances from the gastrointestinal prine with prednisolone (5–10 mg/day). In addition, colonic bacteria metabolise it to lactic of biochemical remission with a normal IgG after 2 years and acetic acids, which inhibit the growth of ammonia- then withdrawal of corticosteroids can be considered. A liver producing organisms and by lowering pH, reduce non-ionic biopsy to confirm remission is recommended before reduc- diffusion of ammonia from the colon into the bloodstream. Long-term remission main- The correct dose is that which produces two to four soft tained by azathioprine is the goal. Exceeding this criteria to determine whether azathioprine can be stopped dose causes dehydration. Patients intolerant of prednisolone respond to budesonide Neomycin and metronidazole inhibit urease-producing (3–9 mg daily orally). Some patients never achieve good control absorbed antibiotic rifaximin is effective over a prolonged with the prednisolone and azathioprine. Surveillance with liver ultrasound and serum a- fetoprotein estimation allows early tumour detection. Fatigue and pruritus are common, early symp- embolisation (with or without chemotherapy) have toms that usually predate jaundice. Liver ultra- riod of 10 years from presentation, but that view is unduly sound shows no evidence of biliary tract disease. The presence mitochondrial antibody in almost all and elevated IgM of bacterial infection is a poor prognostic sign; serum levels with clustering of ‘autoimmune disorders’ in many markers of inflammation suggest bacterial infection, which suggest immune involvement. There is no role (yet) for im- is not necessarily present and related to elevated plasma cy- mune modulation. There may be a The pruritus of cholestasis can be debilitating and has role for early corticosteroids in patients without active sep- been attributed to autotaxin. There is inflammation and excretion), a search for Kayser–Fleischer rings by slit lamp stricturing of the larger intrahepatic and extrahepatic bile examination and diagnostically, an elevated liver copper ducts leading to persistent jaundice and biliary cirrhosis. Genetic analysis is too difficult for routine There is a significant lifetime risk of cholangiocarcinoma. An association with ulcerative colitis, clustering with other D-penicillamine, a copper chelating agent, is the treat- autoimmune disorders and a heritable component, suggest ment of choice for which there is the greatest experience, this is an autoimmune condition. There is no effective but since treatment for Wilson’s disease is lifelong there therapy and no role (yet) for immune modulation. Trientine is an alternative and effective chelating agent, Recurrent episodes of bacterial cholangitis may respond to but there are also long-term concerns. Zinc also reduces cyclical antibiotics that are concentrated in bile and target total body copper content and probably represents the least Gram-negative organisms, e. Iron chelation is chemistry is characteristic, with conjugated bilirubinaemia ineffective. Liver biopsy is almost always abnormal and Interferon-a is available in a pegylated formulation patients can be separated into those with steatosis alone allowing weekly administration by subcutaneous injection. Young fe- at control of weight, hypertension, hyperlipidaemia and males fare best. Interferon-a should tests and some histological features, but have no effect not be used if there is evidence of hepatic decompensation on fibrosis, progression or survival. Agents include lamivudine, telbivudine clavudine, emtricitabine, adefovir, tenofovir and entecavir. Patients on therapy should be immunity, using antibody prepared from pooled plasma monitored to assess viral load. Liver function tests should from immune donors confers temporary protection, but fall to normal in line with the drop in viral load. Because the majority of patients will not develop tion which may be asymptomatic or unrecognised. There is life-threatening liver disease, treatment needs to be tar- no evidence that intervention in acute infection is helpful, geted at those with, or at risk of, fibrosis. Acute infection in an immune sup- years, appears safe in pregnancy, but newer agents cannot pressed host, where there is a high risk of serious disease yet be regarded as safe although there is no evidence yet to or chronic infection, however, should be treated. Chronic infec- tion profiles are not undertaken routinely but a strong case tion is more common in the immune suppressed and the can be made that they should. Treating all patients is neither practical nor appropriate Perhaps the most important issue in determining which and careful assessment of the stage of the disease is critical drugs to use first is the clinical context. Chronic infection follows lowest rate of mutations to date (close to zero in large exposure in 85% of cases and is more likely at extremes of series) but clinical experience is limited to 5 years so far. The rate at which liver disease pro- breakthrough but mutations are much more likely in gresses to cirrhosis varies markedly between individuals, those with past use of lamivudine, which may not be but can be rapid in those acquiring infection over the age recorded. Significant fibrosis at liver biopsy Hepatitis B vaccination predicts progression at subsequent biopsy. Protection lasts from years to decades and it is pegylated interferon-a, given weekly, increasing both com- unclear if booster vaccination is ever required. The mode of immunity’ but are fortunately very rare; thus it is possible action is not known.
Radiology 211:775–780 telangiectasia: a spectrum within a single pathological entity buy generic atacand online. Neurosurgery carotid plaque composition atacand 16 mg online, morphology and neurological symp- 80:217–223 toms 4mg atacand fast delivery. Radiology 93:1071–1078 brain and certain compensatory vascular reactions in carotid- cavernous anastomoses. Nov-Dec (6):12–7 (in russian) 3(5):218–225 Picard L, Bracard S, Moret J et al (1987) Spontaneous dural arterio- Suzuki J (1986) Moyamoya disease. Arch pl):162 (in russian) Neurol 20:288–299 Pollock B, Flickinger J, Lundsford L et al. J Cereb ogy 15:225-237 Blood Flow Metab 19:99–108 Yamamoto K, Nogaki H, Takase Y et al. Georg Tieme Verlag, Vereshchagin N et al (2002) Stroke: principles of diagnosis, treatment, Stuttgart and prevention. Annually, up to 11 per 100,000 new cases of 334 Chapter 4 Histological Classification of Tumours Histological Classification of Tumours of the Central Nervous System of the Central Nervous System 1. Sixty percent of all cases Unlike adults, tumours originating from neuroglia are were tumours originated from neuroepithelial tissue. Approximately two thirds of brain gliomas constituted the largest group among neuroepi- all intracranial neoplasms are benign forms. Teir proportion is from 20 Glial cells are the most numerous among all cellular brain to 40% of all ependymoma in children. However, the proportions of diferent neuroglial are divided into the following groups: (1) astrocytoma, (2) oli- cellular types can vary in diferent brain tissues. So, according to statistical data, approximately two thirds of According to Russell (1989), about 40–45% of all intracra- brain tumours are primary ones, and among them more than nial tumours are gliomas, and they form the heterogeneous 50% are glial neoplasm. But histological structure of glial cells group of brain neoplasms that contain relatively benign forms is not uniform, and they are divided into several cellular sub- as well as very malignant tumours. In this regard, glial tumours are divided into three ba- sic subgroups–astrocytic glioma, oligodendroglioma and ependymoma. Low-grade astrocytoma The term benign astrocytoma is not used at pres- The frst classifcation of neuroepithelial tumours belongs ent due to invasive growth and steady progression to to Bailey and Cushing (1926). It is based on the histological malignancy in time by most of these tumours similarity that is observed between some types of nervous Anaplastic (malignant) astrocytoma system cells developing in the course of normal ontogenesis Glioblastoma and tumour cells. The classifcations taking into account oth- Variant: gliosarcoma er points of view were developed later on. Among them, the Pilocytic astrocytoma classifcations of Kernohan and Sayre (1952), Smirnov (1962), Pleomorphic xanthoastrocytoma Hominskyi (1969), Zulch (1965, 1986), and Russell and Ru- Subependymal giant cell astrocytoma binstein (1989) are the most known. New morphological techniques, Ependymoma such as immunohistochemistry and molecular genetic analy- Anaplastic ependymoma sis, have gained widespread usage. New data about tumour structure led to modi- Mixed Glioma fcation for several times and broadening of this classifcation Oligoastrocytoma in 1993, 2000 (Kleihues and Cavanee 2000) and Louis (2007). Anaplastic oligoastrocytoma According to various estimates, neuroepithelial tumours Others make up 50% of all brain tumours, and this is the most rep- Tumours of the Choroid Plexus resentative group. In adults, these tumours mainly have su- Choroid plexus papilloma pratentorial locations, while for children the lesions of the Choroid plexus carcinoma posterior cranial fossa are more typical. Moreover, it is known that about 10% of benign lesions can develop into more (sinister) malig- Brain Gliomatosis nant forms. According to Piepmeier (1987), 50% of surgically Neuronal and Mixed Neuroglial Tumours treated benign tumours transform into anaplastic astrocyto- Gangliocytoma Dysplastic gangliocytoma of cerebellum (Lhermitte-Duclos) ma or glioblastoma. Ganglioglioma Division of difuse glioma depending on the grade of ma- Anaplastic (malignant) ganglioglioma lignancy is an important point in treatment selection and Central neurocytoma subsequent prognosis. The criteria include the presence of nuclear and cellular poly- morphisms, proliferation of vessel endothelium, presence of mitosis, and foci of necrosis. Tumours with difuse growth, characterised by poor prog- incidence is about 10–15% of all cases of glioma, it afects nosis, belong to the frst category. Tey make up about 75% of young patients and it is characterised by better prognosis. Macroscopically it has grey colour, various blastoma, characterised by the absence of clear macro- and consistency (from dense to gelatine-like) and it is difcult to microscopic borders separating tumour with surrounding tis- separate it from brain tissue. The foci of cystic degeneration can be observed in tumour, The second category of tumours is delimited tumours, with while the foci of necrosis are never found. Microscopically, better prognosis (pilocytic astrocytoma, pleomorphic xan- the fbrillar astrocytoma consists of mature tumour astro- thoastrocytoma and subependymal giant cell astrocytoma). Tey make up area) without pathologically formed arteries or arteriovenous about 6–21% of all intracranial tumours and about 40% of all shunts. In children, the incidence of cerebrum astro- tive, or minimal in the form of an insignifcant disposition of cytoma reaches approximately 30% of all supratentorial brain the cerebral arteries (more ofen anterior and middle cerebral tumours. Such division has a prognostic value, because pilo- venous contrast administration usually does not lead to den- cytic astrocytoma seldom becomes malignant, and it can be sity change, or it can result in a separate hyperintense foci on totally removed, which is not the issue when infltrative fbril- a background of hypodense zone (Figs. Calcifcations in the form of small or large hyperintense The incidence of difuse astrocytomas is about 25–30% of foci are diagnosed in 15–20% of cases (Fig. Cyst forma- all hemispheric gliomas, and approximately about 30% of all tion is a rare albeit possible sign of tumour (Fig. The incidence of logical clearness of tumour borders varies and depends on the supratentorial astrocytomas peaks between 20 and 50 years; level of change of tumour tissue density. Tese sualised in cases of astrocytoma of low density, while isodense tumours can develop in any brain lobe; however, the occipital tumours are characterised by their much worse visibility (Fig. White matter as Afer contrast administration, the density of astrocytoma, well as grey is involved into pathological process. Unfortunately, the prognosis of such dis- cysts is also typical for these astrocytomas. Life expectancy in cases of astrocytoma according to histological structure, these tumours are pilo- Supratentorial Tumours 337 Fig. Cerebral angiography in direct projection does not reveal vascular net of the tumour; the vessels of middle cerebral artery underwent upward disloca- tion (b arterial phase, c capillary phase) Fig. The spread hypodense sity of vessels (middle and posterior cerebral arteries) on the periph- area without clear borders is detected in the lef temporal lobe. The area of uneven density de- crease without clear borders is observed in the lef parietal lobe. Compression and dislocation of the right lateral ventricle is detected 340 Chapter 4 Fig. T2-weighted image (a), T1-weighted image before (b) and afer (c) contrast enhancement. The tumour with relatively homogeneous structure is visualised in the lef frontoparietal area. The destruction of white as well as grey matter is typical It is reasonable to conduct an examination in a frontal pro- for difuse astrocytoma.