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.

714 results found
Article

2005 WHO histological classification of odontogenic tumours

The 2005 WHO histological classification of odontogenic tumours lays out a classification system for neoplasms and other tumours related to the odontogenic apparatus. At the time of writing (2016), it is still the most widely used classification system although a new revision is due to come up i...
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2014 WHO classification of endometrial stromal tumours

Endometrial stromal tumours (EST) constitute <2% of all uterine tumours and <10% of uterine mesenchymal neoplasms 1.  Over the past four decades, EST classification has gone through various modifications, starting from the earliest study by Norris and Taylor 2. This was primarily due to the rar...
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3D conformal radiation therapy

3D conformal radiation therapy (3D-CRT) is a radiation therapy technique that involves CT planning where the volume to be treated is defined on a 3D data set. Therefore, organs at risk can also be delineated with the aim of shielding these and reducing treatment side effects. Radiotherapy planni...
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Abdominal distension (mnemonic)

A mnemonic for causes of abdominal distension (6 Fs) is: F: fat F: fluid  F: flatus F: faeces  F: fetus F: fulminant mass
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Acinic cell carcinoma (lung)

Acinic cell carcinoma of the lung (also known as a Fechner tumour) is a type of lung carcinoma of the salivary gland type. It is extremely rare, especially when it presents in the form of primary acinic cell carcinoma. Pathology Histologically, they are comprised of clear cells with abundant g...
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Acquired tracheo-oesophageal fistula

An acquired tracheo-oesophageal fistula refers to a pathological communication between the trachea and oesophagus due to a secondary cause  Pathology Acquired causes of tracheo-oesophageal fistulae can be divided into those that are related to malignancy (common) and those from other causes (u...
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Acute abdominal pain

Acute abdominal pain is a common acute presentation in clinical practice. It encompasses a very broad range of possible aetiologies and diagnoses, and imaging is routinely employed as the primary investigative tool in its modern management. Terminology A subgroup of patients with acute abdomin...
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Acute airspace opacification with lymphadenopathy (differential)

Acute airspace opacification with lymphadenopathy is a subset of the differential diagnosis for generalised airspace opacification and includes: post-obstructive causes (usually chronic, but 'new' changes can occur) primary lung cancer pulmonary metastases lymphoma/leukaemia infection pri...
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Acute lymphoblastic leukaemia

Acute lymphoblastic leukaemia (ALL) is a malignant disorder of the bone marrow characterised by the proliferation of the lymphoid progenitor cells. Epidemiology ALL is the commonest form of childhood leukaemia, accounting for ~80% of paediatric leukaemia cases 1. In adults, ALL corresponds to ...
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Acute myeloid leukaemia

Acute myeloid leukaemia (AML), also referred to as acute myelogenous leukaemia, is a haematological malignancy characterised by the abnormal clonal proliferation of immature myeloid precursors (myeloblasts) or poorly differentiated cells of the haematopoietic system. It primary infiltrates the b...
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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 are relatively new classification entities which replace the now-defunct term bronchoalveolar carcinoma (BAC). In 2011 the International Association for the Study of Lung Cancer (IASLC) and several...
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Adenocarcinoma in situ of the lung

Adenocarcinomas in situ (AIS) of the lung refer to a relatively new entity for a pre-invasive lesion in the lung. This entity partly replaces the noninvasive end of the previous term bronchoalveolar carcinoma. Adenocarcinoma in situ is defined as a localised adenocarcinoma of <3 cm that exhibits...
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Adenocarcinoma of the lacrimal glands

Adenocarcinoma of the lacrimal glands is rare, with few cases reported in the literature since it was first described in 1996 1. Primary adenocarcinoma of the lacrimal gland is extremely rare; only 9 cases have been reported in the literature 1,2. It can be classified into high- and low-grade ma...
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Adenocarcinoma of the lung

Adenocarcinoma of the lung is the most common histologic type of lung cancer. Grouped under the non-small cell carcinomas of the lung, it is a malignant tumour with glandular differentiation or mucin production expressing in different patterns and degrees of differentiation.  This article bring...
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Adenocarcinoma (urinary bladder)

Adenocarcinoma of the urinary bladder is rare and accounts for only ~1% of all bladder cancers (90% are transitional cell carcinomas). Pathology Metaplasia of urinary bladder induced by chronic irritation or infection can lead to adenocarcinoma. Pathological types of adenocarcinoma of the urin...
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Adenoid cystic carcinoma

Adenoid cystic carcinomas are a rare histological subtype of adenocarcinoma. Pathology Adenoid cystic carcinomas are generally considered low grade 4. The tumours have a notable tendency for perineural spread. Location They have a wide distribution and mainly occur in relation to the airways...
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Adenoid cystic carcinoma of lung

Adenoid cystic carcinoma (ACC) of the lung is a type of non-small cell lung cancer. They are classified under lung carcinomas of the salivary gland type. Primary occurrence in the lung parenchyma is rare, while in the thorax they occur more commonly as adenoid cystic carcinoma of the tracheobron...
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Adenoid cystic carcinoma of the breast

Adenoid cystic carcinoma (ACC) of the breast is a rare subtype of breast cancer. Epidemiology They account for only 0.1-0.4% of all breast cancers. Pathology The tumour demonstrates a strikingly characteristic microscopic pattern similar to that of adenoid cystic carcinoma of the salivary gl...
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Adenoid cystic carcinoma of the salivary glands

Adenoid cystic carcinoma (ACC) of the salivary glands is the second most common malignancy involving the minor salivary glands behind mucoepidermoid carcinoma and the second most common malignancy involving the parotid gland. Pathology Adenoid cystic carcinomas arise more commonly in the minor...
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Adenoid cystic carcinoma of the tracheobronchial tree

Adenoid cystic carcinomas of the tracheobronchial tree are a type of low-grade tracheal tumour. They are considered to be the second most common primary tumour of the trachea. Epidemiology They are usually first recognised in patients in their 4th and 5th decades. There is no recognised gender...
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Adenomatoid odontogenic tumour

Adenomatoid odontogenic tumours are rare and differ from most other dentition related lesions in that they more frequently occur in the maxilla. Epidemiology They are also seen more frequently in females, most frequently in the second decade of life. Radiographic features They present as an ...
Article

Adenosquamous carcinoma (cervix)

Adenosquamous cell carcinoma (ASC) of the cervix is a rare histological subtype of cervical carcinoma. Pathology It has components of both cervical adenocarcinoma and cervical squamous cell carcinoma. Prognosis An adenosquamous histology appears to be an independent predictor of poor outcome...
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Adenosquamous carcinoma of lung

Adenosquamous carcinoma (ASC) of the lung is a rare type of non-small cell lung cancer. Epidemiology It is thought to constituting 0.4-4% of cases non-small cell lung cancer. Pathology The definition of adenosquamous carcinoma indicates a carcinoma showing components of adenocarcinoma and sq...
Article

Adrenal calcification

Adrenal calcification is not a rare finding in healthy asymptomatic people and is usually the result of previous haemorrhage or tuberculosis. Addison disease patients only occasionally develop calcification.  Pathology Aetiology Haemorrhage sepsis: Waterhouse-Friderichsen syndrome blunt abd...
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Adrenal collision tumour

An adrenal collision tumour or collision tumour of the adrenal gland is an uncommon condition where two histologically distinct tumours abut each other or are in close proximity in the same adrenal gland. Pathology Collision tumours have been reported in nearly every organ, for example, collis...
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Adrenal cortical carcinoma

Primary adrenal cortical carcinoma is a highly malignant but rare neoplasm. It may present as a hormonally active or an inactive tumour.  Epidemiology Although men and women are affected equally, functioning tumours are more common in females, who are also more likely to have an associated end...
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Adrenal lymphoma

Adrenal lymphoma can refer to primary adrenal lymphoma: rare  can be bilateral in around 70% of cases 1 secondary involvement of the adrenal glands with lymphoma: more common Clinical presentation Can be variable and can include adrenal insufficiency, worsening general state, weight loss an...
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Adrenal metastases

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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Adult cervical lymphadenopathy (differential)

Cervical lymphadenopathy in an adult can result from a vast number of conditions. They include: malignancy metastases  from head and neck tumours lymphoma other neoplastic lesions Castleman disease Kaposi sarcoma infection bacterial infection viral infection Epstein-Barr virus herpes...
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Aflatoxins

Aflatoxins are naturally-occurring mycotoxins that are produced by Aspergillus species, especially Aspergillus flavus. They are acutely toxic and carcinogenic. Acute exposure High-level aflatoxin exposure can result in acute aflatoxicosis with acute hepatic necrosis, leading to cirrhosis, and ...
Article

Aggressive fibromatosis

Aggressive fibromatosis is a type of musculoskeletal fibromatosis. While it is a non-metastasising fibrous lesion, it is thought to be a true neoplasm that arises from the fascial and musculoaponeurotic coverings, sometimes at the site of a traumatic or post-surgical scar. Terminology The term...
Article

Alveolar soft part sarcoma

Alveolar soft part sarcomas (ASPS) are rare, highly vascular, deep soft tissue malignancy that is classically seen in the lower extremities of young adults. They account for <1% of all soft tissue sarcomas. Epidemiology There is a slight female predilection in patients less than 30 years old 1...
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Ameloblastoma

Ameloblastomas are locally aggressive benign tumours that arise from the mandible, or, less commonly, from the maxilla. Usually present as a slowly but continuously growing hard painless lesion near the angle of the mandible in the 3rd to 5th decades of life, which can be severely disfiguring if...
Article

Anal cancer

Anal cancer is a relatively uncommon, accounting for less than 2% of large bowel malignancies, and most of the cases are made of squamous cell carcinoma.  Epidemiology It accounts for less than 2% of large bowel malignancies and 1-6% of anorectal tumours (~1.5% of all gastrointestinal tract ma...
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Anaplastic lymphoma kinase (ALK) fusion oncogene positive non small cell lung cancer

Anaplastic lymphoma kinase (ALK) fusion oncogene positive non small cell lung cancer refers to a specific set of non small cell lung cancers that contain an inversion in chromosome 2. They are associated with specific clinical features, including never or light smoking history, younger age, and ...
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Anaplastic thyroid cancer (staging)

Anaplastic thyroid cancer staging refers to TNM staging of anaplastic thyroid carcinomas. Papillary, follicular, and medullary thyroid carcinomas are staged separately. The following article reflects the 8th edition manual published by the American Joint Committee on Cancer, which is used for st...
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Anatomy curriculum

The anatomy curriculum is one of our curriculum articles and aims to be a collection of articles that represent the core anatomy knowledge for radiologists and imaging specialists. General anatomy Neuroanatomy Head and neck anatomy Thoracic anatomy Abdominal and pelvic anatomy Spinal anat...
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Angiosarcoma of breast

Breast angiosarcomas are a rare vascular breast malignancy. Epidemiology As primary tumours of the breast, they account for ~0.04% 2 of all breast cancers and tend to occur in younger women, in their 3rd to 4th decades. Secondary angiosarcoma, related to prior therapy of breast cancer, has an...
Article

Ann Arbor staging system

The Ann Arbor staging system is the landmark lymphoma staging classification system for both Hodgkin lymphoma and non-Hodgkin lymphoma.  It is named after the town of Ann Arbor in the US state of Michigan where the Committee on Hodgkin's Disease Staging Classification met in 1971 to agree on it...
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Anterior mediastinal germ cell tumours

Germ cell tumours are one of the causes of anterior mediastinal mass, and any of the germ cell histologies may be identified. They can therefore be divided histologically into: seminoma non-seminomatous germ cell tumours (NSGCT) embryonal cell carcinoma choriocarcinoma yolk sac tumour tera...
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Anterior mediastinal mass in the exam

Getting a film with an anterior mediastinal mass in the exam is one of the many exam set-pieces that can be prepared for. The film goes up and after a couple of seconds pause, you need to start talking: CXR There is a left sided mediastinal mass that makes obtuse angles with the mediastinal c...
Article

Apocrine carcinoma of the breast

Apocrine carcinoma of the breast is a rare variant of breast cancer. The diagnosis is mainly pathological as it is difficult to differentiate from other forms of breast cancer on imaging. Epidemiology It accounts for about 4% of all cases. It is seen most often in females in the age group of 5...
Article

Appendiceal mucocele

Appendiceal mucoceles occur when there is an abnormal accumulation of mucin causing abnormal distention of the vermiform appendix due to various neoplastic or non-neoplastic causes. Epidemiology The reported prevalence at appendicectomy is 0.2-0.3%. They are thought to typically present in mid...
Article

Apple core sign (colon)

The apple core sign, also known as the napkin ring sign (bowel), is most frequently associated with constriction of the lumen of the colon by a stenosing annular colorectal carcinoma. Differential diagnosis The appearance of the apple-core lesion of the colon also can be caused by other diseas...
Article

Asbestosis

Asbestosis refers to later development of diffuse interstitial fibrosis secondary to asbestos fibre 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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Askin tumour

The original description of the Askin tumour (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 tumour, usually of the chest wall. Howev...
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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 carcinoma papillary: 60-80% of carcinomas follicular: 10-20% medullary: 5% anaplastic: 1-2% thyroid ly...
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Asymmetrical density in mammography

Asymmetrical mammographic density, or more simply asymmetries, is a spectrum of morphological descriptors for a unilateral fibroglandular-density finding seen on one or more mammographic projections that does not meet criteria for a mass. The criteria for an asymmetry includes that it is seen o...
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Atypical ductal hyperplasia

Atypical ductal hyperplasia (ADH) is a histologically borderline lesion that has some, but not all the features of ductal carcinoma in situ (DCIS). Sometimes the distinction between ADH and DCIS is simply on the basis of the number of ducts involved.  Pathology Atypical ductal hyperplasia is a...
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Atypical teratoid/rhabdoid tumour

Atypical teratoid/rhabdoid tumours (AT/RT) are an uncommon WHO Grade IV tumour, 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...
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Autoimmune lymphoproliferative syndrome

Autoimmune lymphoproliferative syndrome (ALPS) is a rare lymphoproliferative condition. Clinical presentation It presents with chronic lymphadenopathy, splenomegaly, and symptomatic multilineage cytopenias in an otherwise healthy child. Pathology It represents a failure of apoptotic mechanis...
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BALT lymphoma

BALT lymphoma is an abbreviated term for bronchus-associated lymphoid tissue lymphoma. These neoplasms fall under the broader umbrella of mucosa associated lymphoid tissue (MALT) lymphomas. It is sometimes considered a type of primary pulmonary lymphoma. Clinical presentation Up to half of pat...
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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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Bat wing opacities (lungs)

Bat's wing or butterfly pulmonary opacities refer to a pattern of bilateral perihilar shadowing. It is classically described on a frontal chest radiograph but can also refer to appearances on chest CT 3-4. Differential diagnosis Bat's wing pulmonary opacities can be caused by: pulmonary oedem...
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Benign and malignant characteristics of breast lesions at ultrasound

Benign and malignant characteristics of breast lesions at ultrasound allow the classification as either malignant, intermediate or benign based on work published by Stavros et al. in 1995. Radiographic features Ultrasound Malignant characteristics (with positive predictive values) sonographi...
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Benign metastasising tumours

There are a number of benign metastasising tumours: benign metastasising meningioma 1,2 benign metastasising leiomyoma 3 primary adenoma of thyroid 4 giant cell tumour of bone 5
Article

Benign vs malignant features of gallbladder polyps

In most instances predicting benign versus malignant histology of a gallbladder polyp based purely on imaging features is not possible. However, a number of features are helpful in helping to decide the management of a gallbladder polyp.  Benign features size polyps that are less than 5 mm in...
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Beta-hCG

Beta-hCG (bHCG or β-hCG) is a sex hormone found in the mother's blood serum that can be used to help interpret obstetric ultrasound findings. Beta-hCG levels may be used in three ways in the clinical setting of pregnancy: qualitatively, for presence/absence of fetal tissue more often determin...
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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...
Article

Bilateral testicular lesions

Bilateral testicular lesions have a relatively limited differential diagnosis.  Differential diagnosis Neoplastic  lymphoblastic leukaemia (acute or chronic) lymphoma (non-Hodgkin's) primary testicular lymphoma is rare but the testes are often the site of lymphoma/leukaemia recurrence due t...
Article

Bing-Neel syndrome

Bing-Neel syndrome is an extremely rare neurological complication of Waldenström macroglobulinaemia where there is malignant lymphocyte infiltration into the central nervous system (CNS). Epidemiology The exact incidence is unknown, however, in one study of patients with Waldenström macroglobu...
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Blastic plasmacytoid dendritic cell neoplasm

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare haematological malignancy. It was previously termed as blastic natural-killer lymphoma or agranular CD4+ natural killer cell leukaemia. Epidemiology It only represent a very small proportion (~0.44%) of all haematological malignanc...
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Body imaging

Body imaging is the term assigned to cross-sectional imaging of the body, which radiologically refers to the chest, abdomen and pelvis. It is often used by radiologists who report this region (sometimes known as body imagers/radiologists) to differentiate their primary area of interest from othe...
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Bone lesions with sequestrum

There are several bony lesions that can involve or produce a sequestrum. They include: Common Brodie abscess: osteomyelitis Less common eosinophilic granuloma certain soft tissue tumours (with bony extension)  malignant fibrous histiocytoma lymphoma metastasis (especially from breast c...
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Bone marrow

Normal bone marrow is divided into red and yellow marrow, a distinction made on the grounds of how much fat it contains. Gross anatomy Red marrow is composed of: haematopoietic cells supporting stroma reticulum (phagocytes and undifferentiated progenitor cells) scattered fat cells a rich ...
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Bony sequestrum (mnemonic)

Mnemonics to help remember common causes of bony sequestrum include: E-FILM LIFE FILE Mnemonics E-FILM E: eosinophilic granuloma  F: fibrosarcoma I: infection (Brodie abscess) L: lymphoma (skeletal)  M: malignant fibrous histiocytoma or metastasis (especially from breast carcinoma) LI...
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Borderline ovarian serous cystadenoma

Borderline ovarian serous cystadenomas lie in the intermediate range in the spectrum of ovarian serous tumours and represent approximately 15% of all serous tumours. Epidemiology They present at a younger age group 1-2 than the more malignant serous cystadenocarcinomas with a peak age of prese...
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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. Brachytherapy has been used to treat: prostate cancer breast cancer (ofte...
Article

BRAF

BRAF (B-Raf proto-oncogene serine/threonine-protein kinase) is a proto-oncogene, encoding for a serine/threonine protein kinase. Mutations of BRAF are the most common alteration of the RAS/MAPK pathway and these have been identified in a variety of tumours and congenital syndromes including 1-5:...
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Brain metastases

Brain metastases are estimated to account for approximately 25-50% of intracranial tumours in hospitalised 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....
Article

Brain tumours in infancy

Common brain tumours in infancy (i.e. under one year of age) are quite different from those of brain tumours in adulthood. Most are located in the supratentorial region (~65%) and they carry a poor prognosis. The frequency of these tumours varies according to studies, but the most common brain ...
Article

Breast abscess

A breast abscess is a relatively rare but significant complication of mastitis that may occur during breastfeeding, particularly in primiparous women. The clinical context is a key to diagnosis as imaging appearances (particularly ultrasound) can mimic many other entities such as breast carcinom...
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Breast architectural distortion

Breast architectural distortion is a descriptive term in breast imaging (mammography, ultrasound, and MRI) to indicate that the breast parenchyma is tethered or indented. The finding per se is not a mass. Pathology Architectural distortion is often due to a desmoplastic reaction in which there...
Article

Breast cancer (summary)

This is a basic article for medical students and other non-radiologists Breast cancer is the commonest malignancy in female patients. Reference article This is a summary article; read more in our article on breast cancer. Summary epidemiology 1 in 4 cancer deaths in women worldwide 1 In A...
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Breast imaging-reporting and data system (BI-RADS)

BI-RADS (Breast Imaging-Reporting and Data System) is a risk assessment and quality assurance tool developed by American College of Radiology that provides a widely accepted lexicon and reporting schema for imaging of the breast. It applies to mammography, ultrasound, and MRI. This article refle...
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Breast imaging-reporting and data system (BI-RADS) assessment category 4

A BI-RADS 4 lesion under the breast imaging-reporting and data system refers to a suspicious abnormality. BI-RADS 4 lesions may not have the characteristic morphology of breast cancer but have a definite probability of being malignant. A biopsy is recommended for these lesions. If possible, the ...
Article

Breast implant-associated anaplastic large cell lymphoma

Breast implant-associated anaplastic large cell lymphoma (BIA-ALCL) is a rare form of T-cell primary breast lymphoma that has primarily been associated with textured breast implants.  Epidemiology The entity is rare, with a reported prevalence of between 0.3 in 100,000 to 1 in 1,000 women with...
Article

Breast lymphoma

Breast lymphoma refers to the involvement of the breast with lymphoma and may be primary or secondary. Epidemiology Both primary and secondary breast lymphomas are rare. Breast lymphoma accounts for <1% of all breast malignancies and <2% of all extranodal non-Hodgkin lymphoma 11. Secondary lym...
Article

Breast MRI

Breast MRI is the most sensitive method for detection of breast cancer. Depending on international health regulations, it is either applied for screening of women at high risk for developing breast cancer (e.g. BRCA1 and BRCA2 carriers), as an additional diagnostic test in pretherapeutic breast ...
Article

Breast neoplasms

Breast neoplasms consist of a wide spectrum of pathologies from benign proliferations, high risk lesions, precursor lesions, to invasive malignancies.​ This article provides an overview for radiologists, with a focus on breast cancer. For a summary article for medical students and nonradiologist...
Article

Breast sarcoma

Breast sarcoma refers to a relatively heterogenous group of rare breast tumours which can include: angiosarcoma of the breast pleomorphic sarcoma of the breast fibrosarcoma of the breast myxofibrosarcoma of the breast leiomyosarcoma of the breast primary osteosarcoma of the breast Epidem...
Article

Bright rim sign (DNET)

The bright rim sign, also known as the hyperintense ring sign, has been described in dysembryoplastic neuroepithelial tumours (DNET). It is described as a well defined rim of high signal around the DNET on FLAIR sequences. This T2/FLAIR hyperintense ring, whether complete or in complete, is fai...
Article

British Thoracic Society guidelines for pulmonary nodules

British Thoracic Society guidelines for pulmonary nodules were published in August 2015 for the management of pulmonary nodules seen on CT. In the United Kingdom, they supersede the Fleischner Society guidelines. They are based initially on identifying whether the nodule is solid or subsolid an...
Article

Bronchovascular spread (mnemonic)

A mnemonic to remember diseases that undergo bronchovascular spread is: SKILL Mnemonic S: sarcoidosis K: Kaposi sarcoma I: infection (e.g. pneumocystis pneumonia, tuberculosis) L: lymphoma L: lymphangitis carcinomatosis
Article

BTA ultrasound "U" classification of thyroid nodules

The ultrasound "U" classification of thyroid nodules has been developed by the British Thyroid Association (BTA) as part of their 2014 guidelines on the management of thyroid cancer 1. It allows for stratifying thyroid nodules as benign, suspicious or malignant based on ultrasound appearances t...
Article

Bulging duodenal papilla

Bulging duodenal papilla​ is a conical or cylindrical protuberance at the medial aspect of the descending or horizontal duodenum at the site of the sphincter of Oddi. It is a finding on small bowel follow-though (and endoscopy) and has a relatively long differential. On cross-sectional imaging, ...
Article

Burkitt lymphoma

Burkitt lymphoma is an aggressive B-cell lymphoma predominantly affecting children. Epidemiology Burkitt lymphoma is the most common (40%) type of non-Hodgkin lymphoma in childhood. Median age is eight years with a male predominance (M:F = 4:1) 1. It is less common in adults, accounting for 1-...
Article

CA-125

CA-125 is a high-molecular-weight glycoprotein found on the surface of Mullerian and coelomic epithelial-derived cell types, and is the best known tumour marker for epithelial ovarian cancer 6. Importantly, it may also be elevated in several other conditions (see differential diagnosis section b...
Article

CA 15-3

Carcinoma antigen 15-3, usually shortened to CA 15-3 is a tumour marker used in monitoring breast cancer. The test detects levels of MUC-1, a mucin protein in the blood. MUC-1 is thought to be important in the invasiveness and metastasisation of cancer cells. Physiology MUC-1 is a normal epith...
Article

CA 19-9

CA 19-9 (carbohydrate antigen 19-9 or cancer antigen 19-9) is a serum antigen (monosialoganglioside) that has increased diagnostic use in the management of several malignancies, mainly of hepatopancreaticobiliary origin. It is non-specific, however, and can rise in both malignant and non-maligna...
Article

CA 27-29

CA 27-29 is a tumour marker and is a soluble form of glycoprotein MUC1. It may be elevated in patients with breast cancer. Tumours of the colon, stomach, kidney, lung, ovary, pancreas, uterus, and liver may also raise CA 27-29 levels. Certain non-malignant conditions are also associated with it...
Article

Calcified glial tumours (mnemonic)

In order of decreasing frequency, a useful mnemonic to remember glial tumours which calcify is: Old Elephants Age Gracefully Mnemonic O: oligodendroglioma E: ependymoma A: astrocytoma G: glioblastoma
Article

Calcified mediastinal lymph nodes (differential)

There are numerous causes of calcified mediastinal lymph nodes. Common causes include: infectious granulomatous diseases tuberculosis histoplasmosis sarcoidosis silicosis treated lymphoma Uncommon causes include: Pneumocystis jiroveci (PCP) pneumonia metastases thyroid carcinoma: papi...

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