Syndrome medullary

L. J. Holtermuller, K. H. Arnaud, C. D. "Relations of Calcitonin and Gastrin in the Zollinger-Ellison Syndrome and Medullary Carcinoma of the Thyroid". N. Engl. J. Med. 

Several inherited cancer syndromes are also known to result from mutations in proto-oncogenes. An example is given by the RET proto-oncogene. Depending on the type of mutation and on which part of the gene is affected, RET mutations can lead to multiple endocrine neoplasia 2A or 2B or familial medullary thyroid carcinoma. These familial cancers are inherited in autosomal dominant fashion. A second example is the CDK4 proto-oncogene, which when mutated can cause familial melanoma. 

Renal effects Acute renal insufficiency, interstitial nephritis with hematuria, nephrotic syndrome, proteinuria, hyperkalemia, hyponatremia, renal papillary necrosis, and other renal medullary changes may occur. 

A. Although all of the conditions can present as an asymptomatic nodule in the thyroid, the marked hypercalcemia in this patient makes hyperparathyroidism the probable diagnosis. Carcinomas of the thyroid are common, and outcomes are improved with early diagnosis. Medullary carcinoma and hyperparathyroidism caused by hyperplasia may be inherited and are associated with the multiple endocrine neoplasia syndromes. 

Intracranial atherosclerotic VA obstruction is mainly located at the origin of the posterior inferior cerebellar artery (PICA) and less frequent at the site of dura penetration. Consequently the most frequent clinical syndrome in VA occlusive disease is the dorsolateral medullary syndrome ( Wallenberg s syndrome) consisting of dizziness, retroorbital pain, facial numbness, dissociated sensory deficit, weakness, hoarseness, dysphagia and vomiting, nystagmus, Horner s syndrome and failure of autonomic respiration (Vuilleumier et al. 1995). 

Ho KL, Meyer KR (1981) The medial medullary syndrome. Arch Neurol 38 385-387... 

Subcortical white matter infarcts may mimic a superficial MCA infarct causing a partial anterior circulation syndrome or present as a lacunar syndrome (pure motor, ataxic hemiparesis or sensori motor stroke). Superficial perforating artery infarcts (medullary branches) are often accompanied by cortical spotty lesions. Borderzone and white matter medullary branches infarctions are usually caused by hypoperfusion due lo large vessel occlusion or stenosis (Bogousslavsky 1993 Donnan and Yasaka 1998), but white matter medullary branches infarction can also be caused by cardioembolism (Lee et al. 2003). 

Fig. 14.6. Lateral medullary infarct causing a Wallenberg s syndrome...

Pure motor stroke constitutes about 50% of lacunar cases. It consists of a unilateral motor deficit involving two or three areas, the face, upper arm and/or leg, including the whole of each area that is affected. There are often sensory symptoms but no sensory signs. The lesion occurs at locations where the motor pathways are closely packed together and separate from other pathways usually in the internal capsule or pons, sometimes the corona radiata or cerebral peduncle, and rarely in the medullary pyramid. There may be a flurry of immediately preceding TIAs, the so-called capsular warning syndrome (Donnan et al. 1996). 

Small deep infarcts in the subcortical white matter of the corona radiata may result from small vessel disease affecting the long medullary perforating arteries extending down from cortical branches of the middle cerebral artery or from embolism. Such centrum semiovale infarcts present as either a lacunar syndrome or, occasionally, as a partial anterior cirulation syndrome with cortical features (Read et al. 1998 Lammie and Wardlaw 1999). They are not, however, easy to classify or to distinguish from border zone infarcts deeper in the white matter lying between the arterial territories of the deep perforators from the first part of the middle cerebral artery and the superficial medullary perforators. 

Conus medullaris syndrome has been reported after consecutive intrathecal injections of hyperbaric 1%... 

Distribution of the COX-2 isoform in the adult human kidney is based upon in-situ hybridization and immunolocation studies [11]. COX-2 has been detected in both the macula densa and medullary interstitial cells in patients with Bartter s syndrome and congestive heart failure [22] as well as in elderly patients. COX-1, in addition to being expressed in the glomerulus, is constitutively expressed in both the cortical and medullary collecting ducts [15,16] (Figure 2). The exact role of the duel expression of both COX isoforms in the medullary collecting duct remains to be elucidated. 

Medullary carcinomas of the pancreas, like their colorectal counterparts, often show microsatellite instability, which is usually caused by somatic hypermethyl-ation of the MLHl promoter in sporadic cases " and by an inherited mutation in MLHl or MSH2 HNPCC syndrome.Immunolabeling for MLHl and MSH2 reveals loss of expression of one of these DNA mismatch repair proteins in many cases. 

HEN types 2 and 3 (MEN2. MEN3) are entirely distinct syndromes from MENl. MEN2 is most frequently characterized by medullary carcinoma of the thyroid gland. MEN3 resembles MEN2, although there are several differences. 

In most cases, neoplasia is an individual disease occurring sporadically. However, 5-15% of tumors (in certain types of cancer up to 25% e.g. medullary thyroid carcinoma) is inherited due to a germ line mutation in a tumor suppressor gene or a proto-oncogene. It is noteworthy to mention that genes mutated in inherited cancer syndromes could also play a role in somatic cardnogenesis. 

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