Articles

Articles are a collaborative effort to provide a single canonical page on all topics relevant to the practice of radiology. As such, articles are written and edited by countless contributing members over a period of time. A global group of dedicated editors oversee accuracy, consulting with expert advisers, and constantly reviewing additions.

1,010 results found
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Neuroblastic tumors

Neuroblastic tumors arise from primitive cells of the sympathetic system and include the following entities: neuroblastoma ganglioneuroblastoma ganglioneuroma These entities represent a spectrum of disease from undifferentiated and aggressive (neuroblastoma) to the well differentiated and la...
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Neuroblastoma (staging)

There are two methods of neuroblastoma staging, one that is based on post-operative patients (INSS) and one developed for pre-treatment patients (INRGSS). Staging International Neuroblastoma Staging System (INSS) This staging system is for post-operative patients and mainly for prognosis 1: ...
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Pleomorphic rhabdomyosarcoma

Pleomorphic rhabdomyosarcoma is a type of rhabdomyosarcoma, and is the least common, accounting for only 5% of all rhabdomyosarcomas. Unlike embryonal and alveolar types, these tumors occur in adults over the age of 40 years 1, and are difficult to distinguish from other pleomorphic sarcomas suc...
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Tumors of muscular origin

There are a number of tumors of muscular origin, which overall are relatively uncommon, representing ~2% of benign soft tissue tumors and ~10% of malignant soft tissue tumors 1.  Pathology The tumors can be divided according to the type of muscle fiber: Skeletal muscle origin benign rhabdom...
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Drash syndrome

Drash syndrome, also known as the Denys-Drash syndrome, is associated with an abnormal WT1 gene (Wilms tumor gene) and consists of: Wilms tumor male pseudohermaphroditism progressive glomerulonephritis
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Wilms tumor

Wilms tumor, also known as nephroblastoma, is a malignant pediatric renal tumor. Epidemiology Wilms tumors are the most common pediatric renal mass, accounting for over 85% of cases 1,8 and account for 7% of all childhood cancers 12. It typically occurs in early childhood (1-11 years) with pea...
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WAGR syndrome

The WAGR syndrome or complex stands for: Wilms tumors (greatly increased risk) aniridia genitourinary anomalies intellectual retardation (disability) Pathology Genetics Occurs from a mutation related to chromosome 11p13 3 which is in close proximity to the WT1 gene.
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Ewing sarcoma family of tumors

The Ewing sarcoma family of tumors are a group of small round blue cell tumors that are closely histogenetically related, all demonstrating non-random t(11;22)(q24;q12) chromosome rearrangement resulting in the formation of the EWS-ETS fusion gene 1-3.  Terminology Although the literature is l...
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Ewing sarcoma

Ewing sarcomas are the second most common malignant primary bone tumors of childhood after osteosarcoma, typically arising from the medullary cavity with the invasion of the Haversian system. Ewing sarcomas usually present as moth-eaten, destructive, and permeative lucent lesions in the shaft of...
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Synovial sarcoma

Synovial sarcomas are relatively common intermediate-to-high grade malignant soft tissue tumors, often with an initial indolent course, affecting young patients, and most commonly involving the soft tissue surrounding the knees. Epidemiology Synovial sarcomas typically present in adolescents a...
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Krukenberg tumor

Krukenberg tumor, also known as carcinoma mucocellulare, refers to the "signet ring" subtype of metastatic tumor to the ovary. The stomach followed by colon are the two most common primary tumors to result in ovarian metastases, pursued by the breast, lung, and contralateral ovary. Epidemiology...
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Masaoka staging system of thymoma

The Masaoka staging system is commonly adopted for thymomas 1-3, and is the most important determinant of survival following surgical resection 4: stage I: intact thymic capsule stage II: capsular invasion into adjacent mediastinal fat or pleura stage III: macroscopic invasion into adjacent o...
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CNS capillary telangiectasia

CNS capillary telangiectasias are small, asymptomatic low flow vascular lesions of the brain.  Epidemiology As these lesions are asymptomatic, diagnosis usually matches the age of first imaging with MRI, and as such are most frequently found in middle-aged and elderly adults. Their incidence v...
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Undifferentiated pleomorphic sarcoma

Undifferentiated pleomorphic sarcoma (UPS), previously known as malignant fibrous histiocytoma (MFH), is considered the most common type of soft tissue sarcoma. It has an aggressive biological behavior and a poor prognosis. As in the majority of the cases, UPS affects the extremities and this a...
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Primary hepatic lymphoma

Primary hepatic lymphoma (PHL) is very rare, with approximately 100 described cases. If it is being considered as a diagnosis, distant lymphadenopathy, splenomegaly, bone marrow disease, and leukemia should not be present for at least 6 months after the liver tumor has been detected (see: second...
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Kaposi sarcoma

Kaposi sarcoma (KS) is a low-to-intermediate grade mesenchymal tumor that involves the lymphovascular system. The tumor can involve the pulmonary, gastrointestinal, cutaneous and musculoskeletal systems. Although it is often thought of as an AIDS-related condition, it may also be seen in other p...
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Renal cell carcinoma

Renal cell carcinomas (RCC) (historically also known as hypernephroma or Grawitz tumor) are primary malignant adenocarcinomas derived from the renal tubular epithelium and are the most common malignant renal tumor. They usually occur in 50-70-year old patients and macroscopic hematuria occurs in...
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Vertebra plana

Vertebra plana (plural: vertebrae planae), also known as the pancake, silver dollar or coin-on-edge vertebra, is the term given when a vertebral body has lost almost its entire height anteriorly and posteriorly, representing a very advanced compression fracture. Pathology It can occur in a var...
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Askin tumor

The original description of the Askin tumor (by Askin and Rosai in 1979 1), and many studies following it have led to a great deal of confusion. Until recently it has been considered a separate entity or as a type of peripheral primitive neuroectodermal tumor, usually of the chest wall. However...
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Pleuropulmonary blastoma

Pleuropulmonary blastomas are a rare, variably aggressive, childhood primary intrathoracic malignancy. In up to 25% of cases, the mass can be extrapulmonary with attachment to the parietal pleura. They are classified under sarcomatoid carcinomas of the lungs.  Epidemiology Pleuropulmonary blas...
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Dermatomyositis

Dermatomyositis is an autoimmune inflammatory myositis, which like its closely-related condition polymyositis, carries an increased risk of malignancy. Epidemiology There is a recognized female predilection. It has a bimodal age of presentation depending on the variant: juvenile dermatomyosit...
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Brachytherapy

Brachytherapy, also known as sealed source radiotherapy or endocurietherapy, is a form of radiotherapy where a radioactive source is placed, under the guidance of imaging, within or next to the area requiring treatment. This provides localized targeted internal radiation. Brachytherapy has been...
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Rectal cancer

Rectal cancer, although sharing many of the features of generic colorectal carcinoma (CRC), has different preoperative imaging assessment, with MRI rectum as the mainstay for local staging, and distinct surgical techniques (i.e. total mesorectal excision).  Epidemiology Rectal cancer is genera...
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Rectal cancer (staging)

Staging of rectal cancer strongly predicts the success of and rate of local recurrence following rectal cancer resection. MRI is the modality of choice for the staging of rectal cancer, to guide surgical and non-surgical management options. MRI is used at diagnosis, following downstaging chemora...
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Transitional cell carcinoma of the bladder (staging)

Transitional cell carcinoma of the bladder staging uses the TNM system which has replaced the previously widely used Jewett-Scott-Marshall tumor staging system. It is very similar to the staging of TCC of the renal pelvis and staging of TCC of the ureter. TNM staging (8th edition) T Ta: non-i...
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Small bowel lymphoma

Small bowel lymphoma is one of the most common small bowel malignancies, accounting for ~25% of all primary small bowel malignancies, and ~40% of all primary gastrointestinal lymphomas. Epidemiology Small bowel lymphoma is most commonly secondary extranodal involvement in widespread systemic l...
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Fibrolamellar hepatocellular carcinoma

Fibrolamellar hepatocellular carcinoma is a distinct histological variant of hepatocellular carcinoma characterized on microscopy by laminated fibrous layers between the tumor cells. It is important as it has different demographics and risk factors compared to 'standard' hepatocellular carcinoma...
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Pancreatic metastases

Pancreatic metastases are uncommon and are only found in a minority (3-12%) of patients with widespread metastatic disease at autopsy. They account for only 2-5% of all pancreatic malignancies. Epidemiology Demographics will match those of the primary tumor, but in general, will be in elderly ...
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Raccoon eyes sign (base of skull fracture)

Raccoon eyes sign (or panda eyes in the UK and Ireland) refers to periorbital ecchymosis with sparing of the tarsal plate 3 and is a physical examination finding indicative of a base of skull fracture of the anterior cranial fossa. However it is not pathognomonic for trauma, and there are sever...
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Ultrasound appearances of hepatic metastases

Ultrasound appearance of hepatic metastases can have bewildering variation, and the presence of hepatic steatosis can affect the sonographic appearance of liver lesions. Radiographic features Ultrasound Patterns do exist between ultrasound appearance of the hepatic metastases and the likely p...
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Hepatic metastases

Hepatic metastases are 18-40 times more common than primary liver tumors 6. Ultrasound, CT, and MRI are helpful in detecting hepatic metastases and evaluation across multiple post-contrast CT series, or MRI pulse sequences are necessary.  Epidemiology The demographics of patients with liver me...
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Liver tumors

Liver tumors, like tumors of any organ, can be classified as primary or secondary. Metastases Liver metastases are by far the most common hepatic malignancy, with many of the most common primaries readily seeding to the liver. This is especially the case with gastrointestinal tract tumors, due...
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Bethesda criteria of hereditary non-polyposis colorectal cancer

The Bethesda criteria are an alternative to the Amsterdam criteria for the clinical diagnosis of hereditary non-polyposis colorectal cancer (HNPCC).  Diagnosis of HNPCC is made if any of the following criteria are fulfilled: Amsterdam criteria are met 2 or more HNPCC related malignancies  pa...
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Linitis plastica

Linitis plastica is a descriptive term usually referring to the appearance of the stomach, although the rectum can also be described this way. The appearance is said to be reminiscent of an old leather water-bottle. Pathology The underlying cause is usually a scirrhous adenocarcinoma with diff...
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Gastrointestinal stromal tumor

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract. They account for ~5% of all sarcomas, and are mostly found within the stomach and mid-distal small bowel. They respond remarkably well to chemotherapy. Terminology Previously these tum...
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Paragangliomas of the head and neck

Paragangliomas of the head and neck are rare, representing <0.5% of all head and neck tumors. They arise in a number of locations along the carotid sheath and middle ear including the carotid bifurcation, vagal ganglia, jugular bulb, and tympanic plexus. For a general discussion of the patholog...
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Pancreatic cancer (staging)

Staging of pancreatic cancer (i.e. ductal adenocarcinoma) is traditionally performed according to the American Joint Committee on Cancer (AJCC) / Union for International Cancer Control (IUCC) TNM system.  In the 2017 new edition (8th edition) AJCC published various major changes including exocr...
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Pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) makes up the vast majority (~90%) of all pancreatic neoplasms and remains a disease with a very poor prognosis and high morbidity. On imaging, it usually presents as a hypodense mass on CT that is poorly marginated, which may encase vessels and the common...
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Maxillary antral carcinoma

Maxillary antral carcinomas are an uncommon head and neck malignancy. They usually present late despite growing large since they remain confined to the maxillary sinus and produce no symptoms. Epidemiology Most commonly affects patients over 45 and has a strong male predilection (M:F = 5:1). M...
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Cerebral ring enhancing lesions

The differential for peripheral or ring enhancing cerebral lesions includes: cerebral abscess tuberculoma neurocysticercosis metastasis glioblastoma subacute infarct/hemorrhage/contusion demyelination (incomplete ring) tumefactive demyelinating lesion (incomplete ring) radiation necrosi...
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Optic nerve enlargement

Enlargement of the optic nerves is uncommon. Swelling of the optic nerves has a surprisingly broad differential. Etiology neoplastic optic nerve glioma optic nerve meningioma leukemia orbital lymphoma metastases juvenile xanthogranuloma medulloepithelioma involvement by retinoblastoma ...
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Tram-track sign (orbit)

Tram-track sign refers to the parallel thickening and enhancement around the optic nerve, and is most frequently seen in the setting of optic nerve meningioma. It may, however, also be seen in 1: orbital pseudotumor perioptic neuritis orbital sarcoidosis orbital leukemia orbital lymphoma o...
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Sunburst appearance (bone)

Sunburst or sunray appearance describes two separate findings in the bone: a periosteal reaction and a trabeculation pattern. It should not be confused with the sunburst sign of meningioma vascularity.  Sunburst periosteal reaction Sunburst periosteal reaction reflects aggressive periostitis. ...
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Cervical lymph node (staging)

Cervical lymph node staging refers to evaluating regional nodal metastasis from primary cancer of the head and neck. The following article reflects the 8th edition of the TNM staging system published by the American Joint Committee on Cancer, which is used for staging starting January 1, 2018 1,...
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Papillary tumor of the pineal region

Papillary tumors of the pineal region are one of five pineal parenchymal tumors under the current (2021) WHO classification of CNS tumors with intermediate natural history and a grade of 2 or 3.  Epidemiology Papillary tumors of the pineal region are seen in a wide range of ages, reported from...
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Pineal parenchymal tumor of intermediate differentiation

Pineal parenchymal tumors of intermediate differentiation (PPTID) are, as the name suggests, tumors that fall between pineocytoma (well-differentiated, WHO grade 1) and pineoblastomas (poorly differentiated, WHO grade 4). They are considered WHO grade 2 or 3 tumors 4. Their radiographic appearan...
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Diffuse brainstem glioma (historical)

Diffuse brainstem gliomas or diffuse intrinsic pontine gliomas was a term used to describe infiltrating astrocytomas arising in the brainstem, usually in children. It is no longer recognized as a distinct entity, removed from the 2016 update to the WHO classification of CNS tumors replaced by a ...
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Undifferentiated pleomorphic sarcoma of the retroperitoneum

Undifferentiated pleomorphic sarcomas (UPS), previously known as malignant fibrous histiocytoma (MFH), are an uncommon tumor overall but are considered as one of the most common types of primary retroperitoneal neoplasms.  For a broad discussion of this type of a tumor, which commonly involves ...
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Retroperitoneal leiomyosarcoma

Retroperitoneal leiomyosarcoma, leiomyosarcoma arising within the retroperitoneum, is one of the commonest primary retroperitoneal neoplasms. The retroperitoneum is considered the most common extrauterine site for leiomyosarcoma.  Epidemiology They are more common in women. Clinical presentat...
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Chondroblastoma vs clear cell chondrosarcoma

Distinguishing between a chondroblastoma and epiphyseal clear cell chondrosarcoma can be difficult and differences are listed. Epidemiology Both bone tumors have been reported at any age, but chondroblastomas are usually seen in the 2nd and early 3rd decade whereas clear cell chondrosarcomas h...
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Hepatomegaly

Hepatomegaly refers to an increase in size or enlargement of the liver.  Pathology Etiology Hepatomegaly can result from a vast range of pathology including, but not limited to, the following: malignancy/cellular infiltrate multiple metastases lymphoma(s) leukemia(s) hepatocellular carci...
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Pathological fracture

Pathological fractures are fractures that occur in abnormal bone and occur spontaneously or following minor trauma that would not otherwise fracture biomechanically normal bone. Terminology The term pathological fracture is usually reserved for tumors, either benign or malignant, although it h...
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Extraprostatic extension of prostate cancer

Extraprostatic (extracapsular) extension of prostate cancer refers to local tumor growth beyond the fibromuscular pseudocapsule of the prostate gland into the periprostatic soft tissues, in particular, the periprostatic fat and is an established adverse prognostic factor and of importance for pr...
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Duodenal filling defects

Duodenal filling defects may be caused by a wide variety of duodenal pathology which may be divided by their location and pathological process. Extrinsic gallbladder impression common bile duct impression gas-filled diverticulum Intrinsic Note: please refer to duodenal mucosal nodular fill...
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Splenomegaly

Splenomegaly refers to enlargement of the spleen. The upper limit of the normal adult splenic length is traditionally cited at 12 cm, but lengths upwards of 14 cm can be seen in normal, taller males 7. Terminology Massive splenomegaly is variably defined, including when the spleen is 5 standar...
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Sonographic features of malignant lymph nodes

Lymphadenopathy is quite common, and it can be very difficult to differentiate malignant lymphadenopathy from reactive nodal enlargement. Several gray scale and color Doppler features favor malignancy in a lymph node. Gray scale parameters that favor malignancy size: larger - more likely mali...
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Dense hilum sign

The dense hilum sign suggests a pathological process at the hilum or in the lung anterior or posterior to the hilum. Malignancy, especially lung cancer, should be suspected. Radiographic features On a well-centered chest posteroanterior (PA) radiograph the density of the hilum is comparable on...
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Adrenal calcification

Adrenal calcification is not a rare finding in healthy asymptomatic people and is usually the result of previous hemorrhage or tuberculosis. Addison disease patients only occasionally develop calcification.  Pathology Etiology Hemorrhage sepsis: Waterhouse-Friderichsen syndrome blunt abdomi...
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Adenocarcinoma in situ, minimally invasive adenocarcinoma and invasive adenocarcinoma of lung

Adenocarcinoma in situ, minimally invasive adenocarcinoma and invasive adenocarcinoma of the lung have replaced the now-defunct term bronchoalveolar carcinoma (BAC). In 2011 the International Association for the Study of Lung Cancer (IASLC) and several other societies jointly revised the classi...
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Atypical teratoid/rhabdoid tumor

Atypical teratoid/rhabdoid tumors (AT/RT) are uncommon WHO grade 4 tumors, which in the vast majority of cases occurs in young children less than two years of age. It most frequently presents as a posterior fossa mass. AT/RT often resembles medulloblastoma by imaging and even H&E microscopy, and...
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Celiac plexus block

Celiac plexus block under image guidance is an easy and safe percutaneous procedure with good outcomes for pain palliation in patients who have chronic abdominal pain related to the celiac ganglia.  This usually includes patients with advanced cancers, especially from upper abdominal viscera, s...
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Brainstem glioma

Brainstem gliomas consist of a heterogeneous group that vary greatly in histology and prognosis. Unless otherwise specified, the term brainstem glioma usually refers to the most common histology of a diffuse midline glioma H3 K27M–mutant although many other gliomas can be encountered in the brai...
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Follicular thyroid cancer

Follicular thyroid carcinoma (FTC) is the second most frequent malignancy of the thyroid gland after papillary cancer and accounts for 10-20% of all thyroid neoplasms.  Epidemiology It typically occurs in women and in an older age group than papillary (i.e. 40-60 years of age). Pathology Unl...
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Medulloblastoma

Medulloblastomas are the second most common malignant brain tumor of childhood, with only high-grade gliomas being more common. They most commonly present as midline masses in the roof of the 4th ventricle with associated mass effect and hydrocephalus. Treatment typically consists of surgical re...
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Asbestosis

Asbestosis refers to later development of diffuse interstitial fibrosis secondary to asbestos fiber inhalation and should not be confused with other asbestos related diseases. Epidemiology Asbestosis typically occurs 10-15 years following the commencement of exposure to asbestos and is dose re...
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Intracranial metastatic melanoma

Intracranial metastatic melanoma is the third most common brain metastasis.  For a broad discussion about the primary tumor or brain metastasis in general, please refer to the articles: malignant melanoma cerebral metastases Epidemiology A population-based study of 169,444 cancer patients f...
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Brain metastases

Brain metastases are estimated to account for approximately 25-50% of intracranial tumors in hospitalized patients. Due to great variation in imaging appearances, these metastases present a common diagnostic challenge which can importantly affect the management approach for individual patients. ...
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Malignant melanoma

Malignant melanoma is a malignant neoplasm that arises from melanocytes (or cells that derive from melanocytes).   Pathology Melanocytes predominantly occur in the basal layer of the epidermis and most melanomas, therefore, arise in the skin.  However, melanocytes do occur in other locations a...
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CT angiogram sign (lungs)

The CT angiogram sign refers to vessels appearing prominent during a contrast enhanced CT as they traverse an airless low attenuation portion of consolidated lung. Although initially thought to be specific for bronchoalveolar carcinoma, it has now been recognized as a generic appearance provided...
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Cerebral radiation necrosis

Cerebral radiation necrosis (or radionecrosis) refers to necrotic degradation of brain tissue following intracranial or regional radiation either delivered for the treatment of intracranial pathology (e.g. astrocytoma, cerebral arteriovenous malformation) or as a result of irradiation of head an...
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Pedunculated intratracheal mass

A pedunculated intratracheal mass has a variety of differential diagnoses: benign tumor, e.g. hamartoma, chondroma, lipoma hemangioma inspissated mucus metastasis to tracheal mucosa, e.g. renal cell carcinoma, melanoma polyp, e.g. inflammatory, antrochoanal papilloma post-intubation trach...
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Renal cell carcinoma (TNM staging)

Renal cell carcinoma staging using the TNM staging system for renal cell carcinoma. Older but still widely used system in some practices is the Robson staging system. TNM staging (8th edition) T T1 T1a: tumor confined to kidney, <4 cm T1b: tumor confined to kidney, >4 cm but <7 cm T2: limi...
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Bilateral testicular lesions

Bilateral testicular lesions have a relatively limited differential diagnosis.  Differential diagnosis Neoplastic  lymphoblastic leukemia (acute or chronic) lymphoma (non-Hodgkin's) primary testicular lymphoma is rare but the testes are often the site of lymphoma/leukemia recurrence due to ...
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Unilateral testicular lesions

The differential diagnosis for unilateral testicular lesions is wide-ranging.  Neoplastic Common seminoma (40-50% of testicular malignancies) non-seminomatous germ cell tumors: testicular teratoma testicular epidermoid (teratoma with ectodermal elements only) testicular choriocarcinoma t...
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Pelvic masses in females

Pelvic masses in females carry a broad differential diagnosis: benign adnexal cyst leiomyoma pelvic malignancy dermoid endometriosis pelvic inflammatory disease tubo-ovarian abscess hydrosalpinx pregnancy Extragynaecological masses, e.g. colorectal carcinoma, appendicular abscess, lymp...
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Cerebral ring enhancing lesions (mnemonic)

Convenient mnemonics for the causes of cerebral ring enhancing lesions are: MAGIC DR or DR MAGIC DR MAGIC L MAGICAL DR Mnemonics MAGIC DR or DR MAGIC M: metastasis A: abscess G: glioblastoma I: infarct (subacute phase) or inflammatory (neurocysticercosis, tuberculoma) C: contusion D: ...
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Pulmonary hamartoma

Pulmonary hamartomas (alternative plural: hamartomata) are benign neoplasms composed of cartilage, connective tissue, muscle, fat, and bone. It is one of the most common benign tumors of the lung and accounts for ~8% of all lung neoplasms and 6% of solitary pulmonary nodules. Terminology Pulmo...
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Lucent/lytic bone lesion - differential diagnosis (mnemonic)

Mnemonics for the differential diagnosis of lucent/lytic bone lesions include: FEGNOMASHIC FOG MACHINES They are anagrams of each other and therefore include the same components. They are by no means exhaustive lists, but are a good start for remembering a differential for a lucent/lytic bone...
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Mucoepidermoid carcinoma of salivary glands

Mucoepidermoid carcinoma is a tumor that usually occurs in the salivary glands. It can mimic most other tumors of the glands, and therefore is often considered in the differential.  Epidemiology Mucoepidermoid carcinomas are seen throughout all adult age groups but are most common in middle ag...
Article

Neoplasms of the spinal canal

Neoplasms of the spinal canal encompass a range of tumors which arise from or involve the spinal cord, theca, and spinal nerves. Pathology These can be divided according to the tissue/structure of origin within the spinal canal. Tumors of vertebral bodies are discussed separately: see vertebra...
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Intraventricular neoplasms and lesions

Intraventricular neoplasms are rare and arise from periventricular structures such as the walls of the ventricular system, the septum pellucidum and the choroid plexus. Many tumor types arise from or can bulge into the ventricular system, although there are certain lesions that are relatively re...
Article

Renal osteodystrophy

Renal osteodystrophy (ROD), also known as uremic osteopathy, is a constellation of musculoskeletal abnormalities that occur in patients with chronic renal failure, due to concurrent and superimposed: osteomalacia (adults)/rickets (children) secondary hyperparathyroidism: abnormal calcium and p...
Article

Hypothalamic lesions

Hypothalamic lesions are numerous representing some entities that are unique to the hypothalamus, as well as many lesions that can be seen elsewhere within the brain. Additionally, due to its proximity to the optic chiasm, third ventricle and pituitary region, many lesions of these locations can...
Article

Lymph node enlargement

Lymph node enlargement (rarely lymphadenomegaly) is often used synonymously with lymphadenopathy, which is not strictly correct. Terminology Lymphadenopathy (or adenopathy) is, if anything, a broader term, referring to any pathology of lymph nodes, not necessarily resulting in increased size; ...
Article

Wilms tumor (staging)

Wilms tumor staging is largely anatomical and relates to the invasion and spread of the tumor. Where there is invasion or metastasis, prognosis is poorer. Wilms tumor is one of the more common childhood malignancies. stage I confined to kidney complete resection possible stage II local spre...
Article

WHO classification of odontogenic and maxillofacial bone tumors

The WHO classification of odontogenic and maxillofacial bone tumors, last published in 2017, is a subset of the WHO classification of head and neck tumors (4th edition), which lays out a histological classification system for neoplasms and other tumors related to the odontogenic apparatus. Clas...
Article

Typhlitis

Typhlitis, also known as neutropenic colitis, is a necrotizing inflammatory condition which typically originates in the cecum and, often extends into the ascending colon, appendix or terminal ileum, by the time of presentation. In general patients are immunocompromised, usually neutropenic. Ter...
Article

Tumor thrombus

Tumor thrombus is defined as tumor extending into a vessel, typically a vein. It occurs in a wide variety of malignancies. It is vital to distinguish tumor thrombus from "bland" thrombus (free of neoplastic cells) in the setting of neoplasia, as this often impacts staging and treatment approach....
Article

Transitional cell carcinoma (staging)

Staging of transitional cell carcinomas of the urinary tract vary according to the location of the tumor, and are staged using the TNM staging system.  transitional cell carcinoma of the renal pelvis transitional cell carcinoma of the ureter transitional cell carcinoma of the bladder  
Article

Tracheal masses

The differential for tracheal masses can be rather wide. For a single mass consider: metastasis  direct invasion from adjacent organ (lung, thyroid, esophagus and larynx) distant metastasis (e.g. melanoma, breast, renal, and colon cancer)  primary neoplasms squamous cell carcinoma: commone...
Article

Assessment of thyroid lesions (general)

Assessment of thyroid lesions is commonly encountered in radiological practice. Thyroid mass hyperplastic/colloid nodule/nodular hyperplasia: 85% adenoma follicular: 5% others: rare primary thyroid cancers (carcinoma) papillary: 60-80% of carcinomas follicular: 10-20% medullary: 5% ana...
Article

Temporal lobe epilepsy

Temporal lobe epilepsy (TLE) is the most common type of focal epilepsy syndrome, with often characteristic imaging and clinical findings. It is divided into two broad groups: medial epilepsy most common involves the mesial temporal lobe structures most frequently due to mesial temporal scler...
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TNM staging system

The TNM staging system (officially known as the TNM classification system of malignant tumors) is a cancer staging system overseen and published by the Union for International Cancer Control (UICC). The American Joint Committee on Cancer (AJCC) publishes the AJCC Cancer Staging Manual which is b...

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