Articles

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16,873 results found
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Malignant transformation

Malignant transformation is the term given to the process whereby either normal, metaplastic, or benign neoplastic tissue, becomes a cancer. The process usually occurs in a series of steps and the affected tissue gradually accumulates the genetic mutations that express a malignant phenotype. The...
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Canalis basilaris medianus

The canalis basilaris medianus (median basal canal), also known as clival canal, median clival canal, or inferior median clival canal, refers to a number of anatomic variant midline canals in the clivus, typically involving the basioccipital portion. Gross anatomy These canals are generally we...
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Adrenal metastasis

Adrenal metastases are the most common malignant lesions involving the adrenal gland. Metastases are usually bilateral but may also be unilateral. Unilateral involvement is more prevalent on the left side (ratio of 1.5:1). Epidemiology They are present at autopsy in up to 27% of patients with ...
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Küttner tumor

Küttner tumor refers to a chronic sclerosing sialadenitis. Despite the term tumor, it is a non-neoplastic condition. It is classically described in relation to the submandibular gland but less commonly can also affect the other salivary glands 9 and occasionally also the lacrimal gland 6. Termi...
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Ovarian-Adnexal Reporting and Data System Ultrasound (O-RADS US)

The Ovarian-Adnexal Reporting and Data System Ultrasound (O-RADS US) forms the ultrasound component of the Ovarian-Adnexal Reporting and Data System (O-RADS). This system aims to ensure that there are uniform unambiguous sonographic evaluations of ovarian or other adnexal lesions, accurately ass...
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Neoplasm

Neoplasms, also known as tumors, are pathological masses, caused by cells abnormally proliferating and/or not appropriately dying. Neoplasms may be either benign or malignant. Malignant neoplasms are synonymous with cancers. Benign neoplasms clear origin (unless very large) slow growth  usua...
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Basal cell carcinoma

A basal cell carcinoma (BCC) is one of the commonest non-melanocytic types of skin cancer.  Epidemiology Typically present in elderly fair-skinned patients in the 7th to 8th decades of life. There may be an increased male predilection. Associations Multiple basal cell carcinomas may be prese...
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Retiform hemangioendothelioma

Retiform hemangioendotheliomas or hobnail hemangioendotheliomas are intermediate locally aggressive and rarely metastasizing vascular neoplasms with a distinctive hobnail endothelial cell morphology. Epidemiology Retiform hemangioendotheliomas are rare with <100 cases reported in the literatur...
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Pineocytoma

Pineocytomas are relatively benign (WHO grade 1) pineal parenchymal tumors that have a relatively good prognosis. On imaging, they generally appear as a well-demarcated tumor less than 3 cm in its greatest dimension, iso- to hyperattenuating on CT, hypo- to isointense on T1, and hyperintense on...
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Retroperitoneal hydatid infection

Retroperitoneal hydatid infection refers to the presence of hydatid cyst in the retroperitoneal region of the abdomen. For a general discussion, and for links to other system specific manifestations, please refer to the article on hydatid disease.  Pathology It is generally seen secondary to ...
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Lesser sac hernia

Lesser sac hernias (alternative plural: herniae) are a type of internal hernia, where abdominal contents protrude through the foramen of Winslow, hence they are also known as foramen of Winslow hernia.  Epidemiology Lesser sac hernias are rare, accounting for <0.1% of abdominal hernias and 8% ...
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Breast ultrasound

Breast ultrasound is an important modality in breast imaging. It is the usual initial breast imaging modality in those under 30 years of age in many countries ref. In assessing for malignancy, it is important to remember that one must use the most suspicious feature of three modalities (patholo...
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Superscan

A superscan is an imaging appearance on a Tc-99m diphosphonate bone scan which occurs as a result of a high ratio of bone to soft tissue tracer accumulation. Intense osteoblastic activity in the bones causes diminished renal and background soft tissue uptake. Pathology Etiology This appearanc...
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Modiolus (mouth)

The modiolus (plural: modioli), also known as the modiolus anguli oris or commissural modiolus, is a small fibromuscular structure at the corner of the mouth where fibers from multiple facial muscles converge, and helps coordinate the action of these muscles. Gross anatomy The convergence of t...
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Kimura disease

Kimura disease, also known historically as eosinophilic hyperplastic lymphogranuloma, is a rare benign inflammatory disease that characteristically manifests as enlargement of cervical lymph nodes and salivary glands. Epidemiology Kimura disease typically affects males (80%) between 20-40 year...
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Lemierre syndrome

Lemierre syndrome (also known as postanginal septicemia) refers to thrombophlebitis of the internal jugular vein(s) with distant metastatic anaerobic septicemia in the setting of initial bacterial oropharyngeal infection such as pharyngitis/tonsillitis into lateral pharyngeal spaces of the neck ...
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Myocardium

The myocardium defines the middle layer of the cardiac wall between the endocardium and the pericardium and forms the muscular part of the heart. Gross anatomy The myocardium represents the middle layer of the cardiac wall. It is located between the endocardium and the epicardial layer of the ...
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Miliary lung nodules (mnemonic)

The list of differential diagnoses for miliary lung nodules can be recalled with the mnemonic: TEMPEST Mnemonic TEMPEST T: tuberculosis E: eosinophilic granuloma M: metastases (especially thyroid) P: pneumoconiosis E: extrinsic allergic alveolitis (now known as hypersensitivity pneumonit...
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Cervical rib

Cervical ribs are supernumerary or accessory ribs arising from the seventh cervical vertebra. They occur in ~0.5% of the population, are usually bilateral, but often asymmetric 2, and are more common in females. Related pathology Although cervical ribs are usually asymptomatic, they are the mo...
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Ductus deferens

The ductus deferens (plural: ductus deferentes), formerly known as the vas deferens (plural: vasa deferentia), forms part of the male internal genitalia where it transports sperm from the epididymis to the ejaculatory duct. Terminology In modern anatomic nomenclature, it is no longer referred ...

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