Monday, July 28, 2008
Multicystic Dysplastic Kidney
Multicystic dysplastic kidney (MCDK) is a congenital maldevelopment in which the renal cortex is replaced by numerous cysts of multiple sizes. A dysplastic parenchyma anchors the cysts, the arrangement of which resembles a bunch of grapes. The calyceal drainage system is absent. Typically, MCDK is a unilateral disorder, the bilateral condition is incompatible with life. Furthermore, MCDK with contralateral renal agenesis does not support life. MCDK can be an incidental finding. They show the typical multicystic appearance of MCDK with little or no parenchyma.Cyst wall calcification may be seen.If a contrast-enhanced CT is performed, there is no excretion seen.The management of MCDK is a controversial topic. Routine nephrectomy is not indicated at this time.Surgery is indicated in patients with symptomatic MCDK, suspicious enlargement, hypertension, mass effect, pain, or infection
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Tarlov's Cysts
Tarlov's cysts are located in the perineural space, between the endo-and perineurium at the junction of the posterior nerve root and its ganglion. These lesions either surrounded the entire nerve root or invaded it and became surrounded by compressed nerve fibers. Regardless of the nomenclature or classification system, the defining feature of Tarlov's perineural cyst is the presence of spinal nerve root fibers within the cyst wall or within the cyst cavity itself.The authors of one study found that patients with Tarlov cysts greater than 1.5 cm and with associated radicular pain or bowel/bladder dysfunction benefited most from surgery.
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Medullary Sponge Disease
MSK is characterized by ectasia and cystic formation in the medullary collecting duct. This characterization contrasts with autosomal recessive polycystic kidney disease and with autosomal dominant polycystic kidney disease, in which cysts predominantly develop along the cortical collecting tubule or the entire nephron, respectively.Medullary sponge kidney may be part of other syndromes and conditions such as Beckwith-Wiedemann syndrome (BWS), hemihypertrophy, Caroli disease, Ehlers-Danlos syndrome, Marfan syndrome, and pyloric stenosis.Intravenous pyelography demonstrates radial, linear striations in the papillae or cystic collections of contrast material in ectatic collecting ducts. The result is a characteristic blushlike pattern to the papillae, the so-called "bouquet of flowers" or "paintbrush" appearance. Renal ultrasonography and CT scanning show the collections of calculi and distinguish MSK from papillary necrosis or autosomal dominant polycystic kidney disease.
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Scleroderma - Thoracic manifestations
This 47 year male patient had cardiomegaly, pericardial effusion, dilated oesophagus and secondary idiopathic pulmonary fibrosis. Scleroderma is a chronic disease characterized by excessive deposits of collagen in the skin or other organs. The localized type of the disease, while disabling, tends not to be fatal. The systemic type or systemic sclerosis, the generalized type of the disease, can be fatal as a result of heart, kidney, lung or intestinal damage.Some impairment in lung function is almost universally seen in patients with diffuse scleroderma on pulmonary function testing.Scleroderma can decrease motility anywhere in the gastrointestinal tract.[5] The most common source of decreased motility involvement is the esophagus and the lower esophageal sphincter, leading to dysphagia and chest pain.
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Giant Sigmoid Diverticulum
Giant sigmoid diverticulum is unusual, with only 103 cases previously reported in the world literature.These lesions probably arise as pseudodiverticula of the sigmoid colon with herniation of the mucosa through the muscle wall. The flap-valve mechanism with fibromuscular hyperplasia at the diverticular orifice seen by the pathologist confirms how this giant colonic diverticulum probably developed.All patients with giant sigmoid diverticula are generally elderly, with an age range of 40 to 90 years. The 19% complication rate associated with giant sigmoid diverticulum is relatively high.They are best treated by resection of the diverticulum, in continuity with the involved sigmoid, and primary anastomosis.
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Sunday, July 6, 2008
Neurocysticercosis
Cysticercosis remain a global public health problem in both the developing and developed countries. CT scan and MRI have been useful in the study of the evolution of the cysticercus within the brain parenchyma. MRI is more useful than CT scan in detecting intraventricular and subarachnoidal cysts, as well as the accompanying signs of cyst degeneration and pericystic inflammatory reaction. However, CT scan is preferred for detection of parenchymal calcifications.
Once the oncosphere has passed into the parenchyma, it grows and evolves through vesicular, colloidal, nodular-granular, and calcified phases. The racemose form constitutes a hydropic change that leads to large or even giant vesicles usually devoid of a scolex. Carpio proposed an improved and widely accepted classification system based on the viability and location of the parasite in the host CNS. Active, when the parasite is alive. Transitional, if it is in the degenerative phase. Inactive, if evidence of its death is apparent. Because of the variable clinical course of the disease, treatment must be individualized for each patient. It constitutes antiepileptic and antihelmintic therapy.
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SCFE - Slipped Capital femoral epiphysis
SCFE is one of the most common of the major disorders of the hip in adolescence. It affects boys somewhat more than girls. The usual age is about ten to sixteen years old. It will usually involve one side, but may occasionally be bilateral. SCFE is caused by multiple factors including local trauma, obesity overcoming the physeal plate, inflammatory factors, and possible endocrine abnormalities. Imaging will generally show the posteromedial slip. SCFE can be broken down into two categories: stable and unstable. A stable slip is defined as one where the child can still bear weight on the affected extremity. A slip is considered unstable if the child cannot bear weight on that extremity. Pain indicates that the physis has split. Treatment of a SCFE usually consists of in situ pinning using a cannulated screw introduced over a guide wire.
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Pulmonary Hydatid Cyst
Pulmonary hydatid is caused by larval stage of parasite Echinococcus granulosus. Although surgery still remains the definitive therapy, various workers have tried albendazole and sterilization of cysts with varying result.
Commonest site of cyst is in both lower lobes. X-ray signs include spherical cyst, crescent sign, water lily sign, double arch, pneumonia, hydropneumothorax and blunting of CP angle. In contrast to liver cysts in which calcification occurs in
20 to 30%, calcification of pulmonary hydatid cysts is rare (.07%).
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Ameloblastoma
Ameloblastoma is a rare, benign tumor of odontogenic epithelium (ameloblasts, or outside portion, of the teeth during development) much more commonly appearing in the mandible than the maxilla. Symptoms include painless swelling, facial deformity if severe enough, pain if the swelling impinges on other structures, loose teeth, ulcers, and periodontal (gum) disease. Lesions will occur in the mandible and maxilla,although 75% occur in the ascending ramus area and will result in extensive and grotesque deformitites of the mandible and maxilla. Radiographically, it appears as a lucency in the bone of varying size and features--sometimes it is a single, well-demarcated lesion whereas it often demonstrates as a multiloculated "soap bubble" appearance. Resorption of roots of involved teeth can be seen in some cases, but is not unique to ameloblastoma. Ameloblastomas are relatively resistant to chemotherapy or radiation therapy, thus, surgery is the most common treatment of this tumor.
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Cerebral Angioma
Cavernous angiomas belong to a group of intracranial vascular malformations that are developmental malformations of the vascular bed. These congenital abnormal vascular connections frequently enlarge over time. The lesions can occur on a familial basis. Patients may be asymptomatic, although they often present with headaches, seizures, or small parenchymal hemorrhages.
The sensitivity of MRI to flowing blood and blood products of varying ages, as well as the greater contrast resolution of MRIs, greatly increases the specificity of MRI compared with that of CT. Combining multiple MRI sequences has largely eliminated misdiagnosis of cavernous angiomas, because they have relatively specific signal characteristics. Additionally, gradient-echo imaging, with its increased sensitivity to susceptibility artifact, is useful in the detection of smaller and concomitant lesions, which may not be detected with traditional sequences.
Most cavernous malformations do not produce significant symptoms in patients, and most can simply be followed up over time. For patients in whom lesions cause significant neurologic morbidity, treatment options are available. These options differ depending on the location, size, and amount of the associated hemorrhage. Surgical resection is an option, but depending on the location of the lesion and the patient's existing comorbidities, surgical resection is not the best option in some cases. Stereotactic radiosurgery is an important option in AVMs and hemorrhagic cavernous malformations. The procedure is relatively contraindicated in patients with concomitant venous angiomas because of the high incidence of posttreatment morbidity.
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ABC - Aneurysmal Bone Cyst
An aneurysmal bone cyst is an expansile osteolytic lesion with a thin wall, containing blood-filled cystic cavities. The term aneurysmal is derived from its radiographic appearance. The clinical manifestation depends on the specific site of involvement. A common presentation includes pain of relatively acute onset that rapidly increases in severity over 6-12 weeks.The accuracy of radiography is high, especially with lesions in the appendicular skeleton. Cross-sectional imaging may be useful in defining the extent of spinal, thoracic cage, and pelvic bone involvement. Cross-sectional imaging may not increase the specificity to a large extent.
Differential includes brown tumors in hyperparathyroidism, expansile metastasis from renal cell carcinoma and thyroid carcinoma, hemophilic pseudotumor with hemorrhage,
infestation of bone by a hydatid cyst and telangiectatic osteosarcoma
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