Location of ectopic adrenocortical hormone-secreting tumors causing Cushing's syndrome in the paranasal sinuses

Background. The majority of ectopic adrenocorticotropic hormone (ACTH)-secreting tumors are localized in the chest or abdomen. Occasionally, these tumors are found in the paranasal sinuses. Methods. We present 2 unusual cases of ectopic ACTH syndrome whose ACTH-secreting tumors were localized in the paranasal sinuses and describe their biochemical and radiological presentation. Results. The first patient had an ACTH-secreting olphactory neuroblastoma originating in the ethmoid sinuses. The second patient had a clinical course and biochemical findings indistinguishable from pituitary ACTH-dependent Cushing's syndrome, except for negative petrosal sinus sampling. Head imaging showed a “polyp” in the left maxillary sinus-secreting ACTH. Both patients went into remission following surgicalresection and recovered normal pituitary-adrenal axis function. Conclusion. Ectopic ACTH secretion may originate from lesions in the paranasal sinuses. This accessible location allows for direct immunohistochemical diagnosis with ACTH staining. Surgical resection/radiation therapy can result in complete remission of the disease and restoration of normal pituitary-adrenal function. © 2008 Wiley Periodicals, Inc. Head Neck, 2009.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62139/1/20950_ftp.pd

MiR-92b and miR-9/9* Are Specifically Expressed in Brain Primary Tumors and Can Be Used to Differentiate Primary from Metastatic Brain Tumors

A recurring challenge for brain pathologists is to diagnose whether a brain malignancy is a primary tumor or a metastasis from some other tissue. The accurate diagnosis of brain malignancies is essential for selection of proper treatment. MicroRNAs are a class of small non-coding RNA species that regulate gene expression; many exhibit tissue-specific expression and are misregulated in cancer. Using microRNA expression profiling, we found that hsa-miR-92b and hsa-miR-9/hsa-miR-9* are over-expressed, specifically in brain primary tumors, as compared to primary tumors from other tissues and their metastases to the brain. By considering the expression of only these two microRNAs, it is possible to distinguish between primary and metastatic brain tumors with very high accuracy. These microRNAs thus represent excellent biomarkers for brain primary tumors. Previous reports have found that hsa-miR-92b and hsa-miR-9/hsa-miR-9* are expressed more strongly in developing neurons and brain than in adult brain. Thus, their specific over-expression in brain primary tumors supports a functional role for these microRNAs or a link between neuronal stem cells and brain tumorigenesis

Problem formulation by medical students: an observation study

<p>Abstract</p> <p>Background</p> <p>Medical problems are often complex and ill-structured. In formulating the problem, one has to discriminate pertinent elements from irrelevant information in order to effectively find a solution. In this observation study, we describe how medical students formulate the problem of a complex case.</p> <p>Methods</p> <p>32 third year medical students were presented with a complex case of endocarditis. They were asked to synthesize the case and give the best formulation of the problem. They were then asked to provide a diagnosis. A subsequent group of 25 students were presented with the problem already formulated and were also asked for the diagnosis. We analyzed the student's problem formulations using the presence or absence of essential elements of the case, the use of higher-order concepts and the use of relations between concepts.</p> <p>Results</p> <p>12/32 students presented with the case made the correct diagnosis. Diagnostic accuracy was significantly associated with the use of higher-order concepts and relations between concepts. Establishing explicit relations was particularly important. Almost all students who missed the diagnosis could not elicit any relations between concepts but only reported factual observations. When presented with an already formulated problem, 19/25 students made the correct diagnosis. (p < 0.05)</p> <p>Conclusion</p> <p>When faced with a complex new case, students may not have the structured knowledge to recognize the nature of the problem. They have to build new schema or problem representation. Our observations suggest that this process involves using higher-order concepts and establishing new relations between concepts. The fact that students could recognize the disease when presented with a formulated problem but had more difficulty when presented with the original complex case indicates that knowledge of the clinical features may be necessary but not sufficient for problem formulation. Our hypothesis is that problem formulation represents a distinct ability.</p

Primary Invasive Aspergillosis of the Digestive Tract: Report of Two Cases and Review of the Literature

BACKGROUND: Disseminated aspergillosis is thought to occur as a result of vascular invasion from the lungs with subsequent bloodstream dissemination, and portals of entry other than sinuses and/or the respiratory tract remain speculative. METHODS: We report two cases of primary aspergillosis in the digestive tract and present a detailed review of eight of the 23 previously-published cases for which detailed data are available. RESULTS AND CONCLUSION: These ten cases presented with symptoms suggestive of typhlitis, with further peritonitis requiring laparotomy and small bowel segmental resection. All cases were characterized by the absence of pulmonary disease at the time of histologically-confirmed gastrointestinal involvement with vascular invasion by branched Aspergillus hyphae. These cases suggest that the digestive tract may represent a portal of entry for Aspergillus species in immunocompromised patients

Acute inflammatory myelopathies

Inflammatory injury to the spinal cord causes a well-recognized clinical syndrome. Patients typically develop bilateral weakness, usually involving the legs, although the arms may also become affected, in association with a pattern of sensory changes that suggests a spinal cord dermatomal level. Bowel and bladder impairment is also common in many patients. Recognition of the clinical pattern of spinal cord injury should lead clinicians to perform imaging studies to evaluate for compressive etiologies. MRI of the spine is particularly useful in helping visualize intraparenchymal lesions and when these lesions enhance following contrast administration a diagnosis of myelitis is made. Cerebrospinal fluid analysis can also confirm a diagnosis of myelitis when a leukocytosis is present. There are many causes of non-compressive spinal cord injury including infectious, parainfectious, toxic, nutritional, vascular, systemic as well as idiopathic inflammatory etiologies. This review focuses on inflammatory spinal cord injury and its relationships with multiple sclerosis, neuromyelitis optica, acute disseminated encephalomyelitis and systemic collagen vascular and paraneoplastic diseases