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.

51 results found
Article

CA-125

Serum CA-125 is well recognised as an ovarian cancer-associated marker and is an antigen determinant on a high-molecular-weight glycoprotein. The normal range of CA-125 is 0-35 U/mL. Serum CA-125 levels can also be used to monitor the response to treatment as well as a prognostic indicator sinc...
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CA 19-9 elevation

CA 19-9 (carbohydrate antigen 19-9 or cancer antigen) 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-malignant co...
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Carcinoembryonic antigen

Serum carcinoembryonic antigen (CEA) is a cell-adhesive glycoprotein that was discovered in colorectal cancer in 1965, and is hence one of the oldest and most used tumour markers. Its name derives from its normal expression in fetoembryonic liver, gut and pancreas tissue. Normal range of CEA is...
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Circumferential resection margin

The circumferential resection margin (CRM) is a term used in rectal carcinoma excision surgery (such as total mesorectal excision (TME)). Pathologic evaluation of the resection margin on the excised rectum has been considered important for determining the risk of local recurrence. A margin of ≤...
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Immature ovarian teratoma

Immature ovarian teratomas are uncommon ovarian germ cell tumours. They differ from mature ovarian teratomas (dermoid cysts) both histologically by the presence of immature tissue, and clinically by their more malignant behaviour. Epidemiology They are considerably less common than mature ovar...
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Inferior vena caval thrombosis

Inferior vena caval (IVC) thrombosis is an essential diagnosis while evaluating any neoplastic lesion, or portal hypertension. It is also important to differentiate bland thrombus from tumour thrombus. Clinical features Patient can present with many features which include bilateral pedal oede...
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Inflammatory carcinoma of the breast

Inflammatory carcinomas of the breast also referred as inflammatory breast cancers, are a relatively uncommon but aggressive form of invasive breast carcinoma which has a characteristic clinical presentation and unique radiographic appearances.  Epidemiology   Inflammatory carcinomas account f...
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Intraductal papillary mucinous neoplasm

Intraductal papillary mucinous neoplasms or tumours (IPMNs or IMPTs) are cystic tumours of the pancreas. Epidemiology These tumours are most frequently identified in older patients (50-60 years of age) 6, and thus is sometimes colloquially referred to as the "grandfather lesion". Main duct typ...
Article

Intradural extramedullary metastases

Intradural extramedullary metastases are rare and only account for approximately 5% of spinal metastases. Please refer on leptomeningeal metastases (brain) to a general discussion focused on the brain's subarachnoid space involvement. Epidemiology The age at presentation depends on tumour typ...
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Intramedullary spinal metastasis

Intramedullary spinal metastases are rare, occurring in ~1% of autopsied cancer patients, and are less common than leptomeningeal metastases. Intramedullary lesions may result from: growth along the Virchow-Robin spaces haematogenous dissemination direct extension from leptomeninges Epidemi...
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Intraosseous meningioma

Intraosseous meningioma, also referred as primary intraosseous meningioma, is a rare subtype of meningioma that accounts for less than 1% of all osseous tumours. They fall under the subgroup of primary extradural meningiomas. Terminology It is important to note that it has been argued by some ...
Article

Inverted papilloma

Inverted papillomas are a type of Schneiderian papilloma. They are uncommon with distinctive pathological and imaging features. Terminology  The term inverted papilloma is also used to describe a urothelial lesion. For a discussion of that entity, please refer to inverted papilloma of the urin...
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Juxtaglomerular cell tumour

Juxtaglomerular cell tumour (JGCT) is an infrequent renal tumour of the juxtaglomerular cells. These cells secrete renin and often cause severe hypertension and hypokalaemia. Epidemiology JGCT affects all age groups, but is most common in adolescents and young adults, with peak prevalence in t...
Article

Leiomyosarcoma

Leiomyosarcomas (LMS) are extremely rare malignant neoplasms that originate from smooth muscle cells and may be considered the malignant counterpart of a leiomyoma. They are classified as a soft tissue tumour and account for ~8% of malignant soft tissue tumours 10. Pathology Location  Leiomyo...
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Lipoblastoma

Lipoblastoma is a rare, benign, encapsulated tumour arising from embryonic white fat.  It occurs primarily in infancy and early childhood (more than 90% before age 3). It most often occurs in the extremities and trunk, although it can be seen in other areas 1. The entity was originally describe...
Article

Lipoblastoma of lung

Lipoblastoma of the lung is a fat derived thoracic tumour. Epidemiology They occur during infancy and early childhood. More than 90% of cases are diagnosed in children less than 3 years of age, with nearly 75% occurring before the age of 12 months Pathology Lipoblastomas are rare soft-tissue...
Article

Lymphoma

Lymphoma is a malignancy arising from lymphocytes or lymphoblasts. Lymphoma can be restricted to the lymphatic system or can arise as extranodal disease. This, along with variable aggressiveness results in a diverse imaging appearance. Epidemiology Lymphoma accounts for ~4% of all cancers 4. T...
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Muscle lymphoma

Muscle lymphoma is a rare manifestation of lymphoma. Epidemiology Muscle lymphoma is rare, representing <2% of all lymphomas. Average age of presentation is 70 years 1. Risk factors HIV/AIDS 3 Clinical presentation Focal swelling and/or pain along with B-type symptoms 2. Any muscle can be ...
Article

Mycosis fungoides

Mycosis fungoides (MF), also known as cutaneous T-cell lymphoma, is a type of malignant T-cell lymphoma that primarily involves the skin.  Epidemiology In the United States, it is more common in males and African Americans. In Europe, it accounts for ~6% of all non-Hodgkin lymphomas. It is rar...
Article

Myeloproliferative disorder

Myeloproliferative disorders (MPDs) are a diverse group of conditions that are characterised by the overproduction of red cells, white cells and/or platelets in bone marrow. There are numerous conditions considered in this group but the most common are:  myelofibrosis polycythaemia vera essen...
Article

Nasopharyngeal carcinoma

Nasopharyngeal carcinomas (NPC) are the most common primary malignancy of the nasopharynx. It is of squamous cell origin, some types of which are strongly associated with the Epstein-Barr virus (EBV). Epidemiology Nasopharyngeal carcinoma accounts for ~70% of all primary malignancies of the na...
Article

Neonatal neuroblastoma

Neonatal neuroblastoma is a type of congenital neuroblastoma, an embryonal tumour arising from the sympathetic nervous system. In the majority of cases (45%), the tumour is localised in the adrenal gland.  Epidemiology Neonatal neuroblastoma accounts for less than 5% of all cases and carries ...
Article

Nonbacterial thrombotic endocarditis

Nonbacterial thrombotic endocarditis (NBTE), also referred as marantic endocarditis, refers to fibrin and platelets aggregations on previously undamaged heart valves, in patients without bacteraemia. The condition is seen in patients with advanced stage malignancies, and is related to episodes o...
Article

Ovarian thecoma

Ovarian thecomas are benign ovarian tumours of sex cord / stromal (mesenchymal) origin. They are thought to account for approximately 0.5-1% of all ovarian tumours. As ovarian thecomas secrete oestrogen, they are described as functional ovarian tumours. Epidemiology They typically present in o...
Article

Paget disease of the breast

Paget disease of the breast, which is also known as Paget disease of the nipple, has traditionally been described as a form of breast malignancy characterised by infiltration of the nipple epidermis by malignant cells. Although most cases have underlying focus or foci of in situ or invasive carc...
Article

Perineural spread of tumour

Perineural spread of tumour is a form of local invasion in which primary tumours cells spread along the tissues of the nerve sheath.  It is a well-recognised phenomenon in head and neck cancers. An important distinction has to be made between perineural invasion (PNI) and perineural spread (PNS...
Article

Peritoneal mesothelioma

Peritoneal mesothelioma is an uncommon primary tumour of the peritoneal lining. It shares epidemiological and pathological features with but is less common than its pleural counterpart, which is described in detail in the general article on mesothelioma. Other sub-types (also discussed separatel...
Article

Pheochromocytoma

Pheochromocytomas are an uncommon tumour of the adrenal gland, with characteristic clinical, and to a lesser degree, imaging features. The tumours are said to follow a 10% rule: ~10% are extra-adrenal ~10% are bilateral ~10% are malignant ~10% are found in children ~10% are familial ~10% a...
Article

Primary bone lymphoma

Primary bone (skeletal/osseous) lymphoma (PBL) is a less common manifestation of lymphoma than secondary involvement from disseminated lymphoma. It is rare, accounting for <5% of bone tumours and <1% of non-Hodgkin lymphoma. Terminology PBL is defined as the presence of lymphoma isolated to on...
Article

Primary mediastinal large B-cell lymphoma

Primary mediastinal large B-cell lymphoma is a distinct entity, recognised in the WHO classification of lymphoma. Epidemiology Primary mediastinal large B-cell lymphoma accounts approximately 5% of large B-cell lymphoma, which is usually disseminated or found in the abdomen. There appears to b...
Article

Primary pleural lymphoma

Primary pleural lymphoma is extremely rare, especially in immunocompetent patients. Epidemiology Primary pleural lymphoma accounts for <0.5% of all non-Hodgkin lymphoma 2 and ~2.5% of primary chest wall tumours 4.  Pathology Primary pleural lymphoma may be Hodgkin or non-Hodgkin lymphoma wit...
Article

Primary pulmonary lymphoma

Primary pulmonary lymphoma (PPL) refers to a clonal lymphoid proliferation affecting the lungs without any detectable extrapulmonary involvement. It is a much rarer type of pulmonary lymphoma and is most frequently represented by lymphoma of B cell lineage - often marginal zone B-cell lymphoma o...
Article

Primary uveal malignant melanoma

Malignant uveal melanomas, also referred as choroidal melanomas, are the most common primary tumour of the adult eye 3.  Epidemiology Malignant melanoma of the uvea is the most common primary intraocular malignancy and is predominantly seen in Caucasians 5. The incidence of these tumours incre...
Article

Pulmonary artery sarcoma

Pulmonary artery sarcomas are extremely rare tumours that originate from the intimal mesenchymal cells of the pulmonary artery. It is frequently misdiagnosed as pulmonary thromboembolism.  Epidemiology  Primary malignant tumours of the pulmonary arteries are very rare with an incidence of 0.00...
Article

Pulmonary lymphoma

Pulmonary lymphoma refers to lung parenchymal involvement with lymphoma. It can be broadly divided as primary or secondary. primary pulmonary lymphoma: (rare) usually non-Hodgkin lymphoma which is limited to the lung with or without mediastinal lymph node involvement and with no evidence of ex...
Article

Radial scar

Radial scar, or complex sclerosing lesion, is a rosette-like proliferative breast lesion. It is not related to surgical scarring. Some authors, however, reserve the latter term to lesions over 1 cm 5.  It is an idiopathic process with sclerosing ductal hyperplasia.  Its significance is that it...
Article

Renal oncocytoma

Renal oncocytoma is a relatively benign renal tumour. The main clinical importance of this lesion is the difficulty in pre-operatively distinguishing it from renal cell carcinomas, as epidemiology, presentation, imaging and even histology can be very similar.  Epidemiology Renal oncocytomas ac...
Article

Rhabdomyosarcomas (biliary tract)

Rhabdomyosarcomas of the biliary tract are rare tumours, usually identified in children, with a very poor prognosis. They are usually grouped under botryoid rhabdomyosarcomas. For a general discussion of this type of tumour, please refer to the article on rhabdomyosarcomas. Epidemiology Rhabd...
Article

Sarcoid-like post-immunotherapy granulomatosis

Sarcoid-like post-immunotherapy granulomatosis has been reported as an uncommon complication in patients treated with immunotherapy agents such as monoclonal antibodies. It was first reported in TNF inhibitors used to treat rheumatoid arthritis and has also been reported in various immunotherapy...
Article

Secondary hepatic involvement with lymphoma

Secondary hepatic involvement with lymphoma (secondary hepatic lymphoma) is common, much more so than primary hepatic lymphoma.  Clinical presentation Hepatomegaly with deranged liver function tests is the most common presentation. Jaundice is common. Rarely, patients may present with acute li...
Article

Secondary involvement of the bone with lymphoma

Secondary involvement of the bone with lymphoma, also referred as secondary bone lymphoma, is much more common than primary bone lymphoma, occurring in ~15% of disseminated lymphomas. Terminology Secondary bone lymphoma is defined as lymphoma involving the bone with nodal disease occurring wit...
Article

Secondary involvement of the pleura with lymphoma

Secondary involvement of the pleura with lymphoma (secondary pleural lymphoma) is very common, occurring in ~20% of lymphomas. It may be a result of an extension of lymphoma into the visceral or parietal pleura or be a complicating pleural effusion and is a poor prognostic factor.  Epidemiology...
Article

Sinonasal adenocarcinoma

Sinonasal adenocarcinomas are primary tumours of the sinonasal region with glandular differentiation. They are grossly classified as salivary and non-salivary subtypes. However, generally in the literature and IARC/WHO classification, the term Sinonasal adenocarcinoma refers to non-salivary aden...
Article

Sinonasal lymphoma

Sinonasal lymphoma refers to the involvement of the nasal cavity and/or paranasal sinuses with lymphoma. It can be primary or secondary. Clinical presentation Presenting symptoms of sinonasal lymphoma are variable but are usually similar to those of benign inflammatory diseases. The clinical s...
Article

Sinonasal mucosal melanoma

Sinonasal mucosal melanoma (SNMM) is a very rare and unique subtype of malignant melanoma. Epidemiology SNMMs account for ~1% of malignant melanomas and <4% of head and neck cancers 1,2. They affect older patients (60-90 years old) 2. There is a higher incidence in Japan 5.  Clinical presenta...
Article

Skeletal muscle metastases

Skeletal muscle metastases are uncommon compared to other sites and are generally seen in the context of widespread metastatic disease.  Epidemiology Post-mortem rates of skeletal metastases vary between 0.03% and 17% 1.  Clinical presentation Most commonly asymptomatic 2,3.  Pathology Com...
Article

Small bowel lymphoma

Small bowel lymphoma is the most common small bowel malignancy, accounting accounts 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 ly...
Article

Spinal astrocytoma

Spinal astrocytomas are the second most common spinal cord tumour overall, representing 40% of intramedullary tumours 3. They account for 60% of paediatric intramedullary tumours, making them the most common spinal cord tumour in children 6. This article specifically relates to spinal astrocyto...
Article

Squamous cell carcinoma of the lung

Squamous cell carcinoma (SCC) is one of the non-small cell carcinomas of the lung, overtaken by adenocarcinoma of the lung as the most commonly encountered lung cancer.  Epidemiology Squamous cell carcinoma accounts for ~30-35% of all lung cancers and in most instances are due to heavy smoking...
Article

Superior vena cava obstruction

Superior vena cava (SVC) obstruction can occur from extrinsic compression, intrinsic stenosis or thrombosis. Malignancies are the main cause and are considered an oncologic emergency. Superior vena cava syndrome (SVCS) refers to the clinical syndrome with symptoms that results from this obstruct...
Article

Tumour markers

Tumour markers are a group of molecules in serum that are elevated in various malignancies and are often used to monitor treatment response as well as alert for potential progressive disease when in remission. Commonly used markers include: AFP beta-hCG CA 19-9 CA-125 CEA chromogranin A P...

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