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.

447 results found
Article

Colon polyp

Colon polyps are mucosal outgrowths of the colon wall. They are of interest to physicians and radiologists because of the accepted progression of adenomatous polyps to colon carcinoma. Pathology adenomatous colon polyps tubular polyps tubulovillous polyps villous colon polyps dysplastic co...
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Colorectal cancer (summary)

This is a basic article for medical students and other non-radiologists Colorectal cancer, also called colorectal carcinoma (CRC), is the most common cancer of the gastrointestinal tract and the second most frequently diagnosed malignancy in adults. CT and MRI are the modalities most frequently...
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Colorectal carcinoma

Colorectal carcinoma (CRC) is the most common cancer of the gastrointestinal tract and the second most frequently diagnosed malignancy in adults. CT and MRI are the modalities most frequently used for staging. Surgical resection may be curative although five-year survival rate is 40-50%. Epidem...
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Computed tomography texture analysis

Computed tomography texture analysis (or CTTA) is a new useful biomarker that provides an objective and quantitative assessment of tumour heterogeneity by analysing the differences in the pixel values of an image. Parameters assessed  Gray-level frequency distribution: pixel intensity histogra...
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Congenital heart disease chest x-ray (an approach)

With the advent of echocardiography, and cardiac CT and MRI, the role of chest radiographs in evaluating congenital heart disease has been largely been relegated to one of historical and academic interest, although they continue to crop up in radiology exams. In most instances a definite diagnos...
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Congenital neuroblastoma

A congenital neuroblastoma is defined as neuroblastoma identified within a month of birth, and is divided into : fetal neuroblastoma neonatal neuroblastoma In most cases they present as stage 1, 2 or 4S (see neuroblastoma staging). Fetal neuroblastoma In 90% of cases fetal neuroblastomas ar...
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Cortically-based brain tumours (mnemonic)

A handy mnemonic to recall cortically-based brain tumours is: PDOG Mnemonic P: pleomorphic xanthoastrocytoma D: dysembryoplastic neuroepithelial tumour (DNET); desmoplastic infantile astrocytoma and ganglioglioma O: oligodendroglioma G: ganglioglioma
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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 recognised as a generic appearance provided...
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CT guided thoracic biopsy

CT guided thoracic biopsy is usually performed for the diagnosis of suspicious lung, pleural or mediastinal lesions. It can be performed as an outpatient where patient monitoring and complications support are available.  A small percentage of lung and pleural biopsies may be performed under ultr...
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Curtain sign

The curtain sign (or draped curtain sign) in neuroimaging refers to the appearance of a vertebral body mass that extends to the anterior epidural space. The posterior longitudinal ligament is strongly attached to the posterior vertebral body cortex in the midline and is more loosely attached la...
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Cutaneous and subcutaneous metastases

Cutaneous and subcutaneous metastases are not uncommon, occurring in ~5% (range 0.7-10.4%) of internal malignancies, and representing 2% of skin cancers. Sister Mary Joseph nodule is a well known cutaneous metastases. Pathology These metastases can come from haematogenous or lymphatic spread, ...
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Cystic adrenal neoplasm

Cystic adrenal neoplasms are uncommon and only account for a minority of cystic adrenal lesions 3. They may be represented several histological types: adrenal adenoma 1 adrenal cortical carcinoma 1,2 adrenal epithelioid angiosarcoma 2 phaeochromocytoma 1 Differential diagnosis Consider adr...
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Cystic glioblastoma

Cystic glioblastoma is a descriptive term for one form of glioblastoma that contains a large cystic component, rather than being a pathological subtype.  Please refer to the main article on glioblastoma for a broad discussion on this tumour.  Radiographic features The main challenge in discri...
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Cystic lesions of the pancreas (differential)

The differential for cystic lesions of the pancreas includes: unilocular pancreatic pseudocyst intraductal papillary mucinous neoplasm (IPMN) serous cystadenoma uncommonly uni/macrolocular simple pancreatic cyst pancreatic cysts occur in association with  von Hippel Lindau syndrome autos...
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Cystic meningioma

The term cystic meningioma is applied to both meningiomas with intratumoral degenerative cyst formation as well as those with peritumoral arachnoid cysts or reactive intraparenchymal cysts.  They should not be confused with microcystic meningiomas, a distinct variant, in which the cysts are mic...
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Cystic (necrotic) lymph nodes

Cystic or necrotic appearing lymph nodes can be caused by a number of infectious, inflammatory or malignant conditions: Systemic squamous cell carcinoma metastases treated lymphoma leukemia plasmacytoid T-cell leukemia acute myeloid leukemia viral lymphadenitis herpes simplex lymphadenit...
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Cystic pulmonary metastases

Cystic pulmonary metastases are atypical morphological form on pulmonary metastases where lesions manifest as distinct cystic lesions. It is slightly different form the term cavitating pulmonary metastases in that the lesions are extremely thin walled. Pathology It has been reported with many ...
Article

Deauville five-point scale

The Deauville five-point scale (Deauville 5ps) is an internationally recommended scale for clinical routine and clinical trials using FDG-PET/CT in the initial staging and assessment of treatment response in Hodgkin lymphoma (HL) and certain types of non-Hodgkin lymphomas (NHL).  Inclusions FD...
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Deep inguinal lymph nodes

The deep inguinal nodes are located within the femoral sheath, medial to the femoral vein. They receive afferent lymphatic drainage from the deep lymphatics of the distal lower extremity and perineum (e.g. glans penis / clitoris), and drain proximally into external iliac lymph nodes via channels...
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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-centred chest posteroanterior (PA) radiograph the density of the hilum is comparable on ...
Article

Dermatofibrosarcoma protuberans

Dermatofibrosarcoma protuberans (DFSP) is an uncommon exophytic, slow growing, low grade, spindle cell tumour arising in the dermal and subcutaneous tissues, particularly of the trunk region with excellent outcome after complete surgical resection. Epidemiology The tumour occurs in patients of...
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Dermatomyositis

Dermatomyositis is an autoimmune inflammatory myositis. Epidemiology There is a recognised female predilection. It has a bimodal age of presentation depending on the variant: juvenile dermatomyositis (JDM): affects children and tends to be more severe adult dermatomyositis (ADM): typically a...
Article

Desmoid tumour

Desmoid tumours are benign, non-inflammatory fibroblastic tumours (see WHO 2002 classification of soft tissue tumours) with a tendency for local invasion and recurrence but without metastasis. Terminology The terms desmoid tumour and aggressive fibromatosis are occasionally used synonymously b...
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Desmoplastic fibroma

Desmoplastic fibromas are extremely rare bone tumours that do not metastasise but may be locally aggressive. They are considered to be a bony counterpart of soft tissue desmoid tumours and are histologically identical.  Clinical presentation Incidence is ~0.3%. The most common areas of involve...
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Desmoplastic small round cell tumour

Desmoplastic small round cell tumours are a rare and highly aggressive primary peritoneal malignancy. Epidemiology They are usually seen in young adolescents and has male predominance with a mean survival of 2-3 years. Clinical presentation It usually presents with a palpable abdominal mass ...
Article

Diabetic mastopathy

Diabetic mastopathy is a condition characterised by the presence of a benign tumour like breast masses in women with long-standing type 1 or type 2 insulin-dependent diabetes. The condition has also been reported in men. A similar condition is lymphocytic mastitis but this occurs in non-diabetic...
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Differential diagnosis for a focal gas collection in the right upper quadrant

A gas filled focal collection in the right upper upper quadrant on plain film can occur from a number of pathologies. Things to consider are entero biliary fistula : common types include cholecysto-duodenal fistula and cholecysto-colic fistula and. Can occur with  gallstone ileus (majority of ...
Article

Differential for an anterosuperior mediastinal mass

An anterosuperior mediastinal mass can be caused by neoplastic and non-neoplastic pathology. As their name suggests, they are confined to the anterior mediastinum, that portion of the mediastinum anterior to the pericardium and below the level of the clavicles.  The differential diagnosis for a...
Article

Diffuse astrocytoma

Diffuse astrocytomas, also referred to as low-grade infiltrative astrocytomas, are designated as WHO II tumours of the brain. The term diffuse infiltrating means there is no identifiable border between the tumour and normal brain tissue, even though the borders may appear well-marginated on imag...
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Diffuse bony sclerosis (mnemonic)

Useful mnemonics for remembering causes of diffuse bony sclerosis include: 3 M's PROOF Regular Sex Makes Occasional Perversions Much More Pleasurable And Fantastic 1   Mnemonics 3 M's PROOF M: malignancy metastases (osteoblastic metastases) lymphoma leukaemia M: myelofibrosis M: mastoc...
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Diffuse brainstem gliomas

Diffuse brainstem gliomas, also known as diffuse intrinsic brainstem glioma (DIBG), is a term used to describe infiltrating astrocytomas, no longer recognised as a distinct entity in the 2016 update to the WHO classification of CNS tumours. It encompassed a variety of tumours, ranging from WHO g...
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Diffusely increased bone marrow FDG uptake

A diffuse homogeneous bone marrow FDG uptake usually reflects hyperplastic bone marrow which can be seen in the following conditions: therapy-related granulocyte colony stimulating factor (G-CSF) post-chemotherapy erythropoietin pathological process myelodysplastic syndromes beta thalasse...
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Ductal adenoma of the breast

A ductal adenoma of the breast is a benign glandular tumour of the breast that usually fills and distends the ductal lumen. Epidemiology They may occur in women of all ages, although the majority of patients are 60 years of age or greater 3. Clinical presentation Ductal adenomas usually pres...
Article

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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Dural metastases

Dural or pachymeningeal metastases are a relatively common cause of dural masses, although they are less common than brain metastases and meningiomas. They can occur both within the spine and intracranially - this article is focussed on intracranial dural masses.  Clinical presentation Patient...
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Dysembryoplastic neuroepithelial tumour

Dysembryoplastic neuroepithelial tumours (DNET) are benign (WHO Grade I) slow growing glioneuronal tumours arising from either cortical or deep grey matter. The vast majority are centred in cortical grey matter, arise from secondary germinal layers, and are frequently associated with cortical dy...
Article

Dysplastic liver nodules

Dysplastic liver nodules are focal nodular regions (≥ 1 mm) without definite evidence of malignancy. Epidemiology They have been found in cirrhotic patients with a prevalence of 14% (size >1.0 cm) to 37% (size >0.5 cm) 2. Pathology Dysplasia indicates: nuclear atypia increased fat or glyco...
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ECOG performance status

The Eastern Cooperative Oncology Group (ECOG) is one of the largest clinical cancer research organizations in the United States and conducts clinical trials in all types of adult cancers. The ECOG performance status is a scale used to assess how a patient's disease is progressing, assess how th...
Article

Endometrial carcinoma

Endometrial carcinoma is generally considered the most common gynaecological malignancy 1,5. It frequently presents with vaginal bleeding. Both ultrasound and pelvic MRI are useful modalities for evaluation. Epidemiology Incidence peaks at around the 6th decade, though 12% of cases present in ...
Article

Endometrial hyperplasia

Endometrial hyperplasia refers to an increased proliferation of the endometrial glands relative to the stroma. One of the main concerns is the potential malignant transformation of the endometrial hyperplasia to the endometrial carcinoma. Epidemiology Endometrial hyperplasia affects women of a...
Article

Endosteal scalloping

Endosteal scalloping refers to the focal resorption of the inner layer of the cortex (i.e. the endosteum) of bones, most typically long bones, due to slow-growing medullary lesions. It is important to note that although it is evidence of a slow non-infiltrative lesion, it does not equate to ben...
Article

Ependymoma

Ependymomas represent a relatively broad group of glial tumours most often arising from the lining the ventricles of the brain or the central canal of the spinal cord. They account for ~5% of all neuroepithelial neoplasms, ~10% of all paediatric brain tumours and up to 33% of brain tumours occur...
Article

Extramedullary haematopoiesis in the spleen

Extramedullary haematopoiesis in the spleen represents a physiologic compensatory event that may be seen in many haematologic diseases leading to chronic anaemia. The liver and the spleen are the most common site of extramedullary haematopoiesis, both usually manifesting on imaging as organomega...
Article

Facial nerve schwannoma

Facial nerve schwannoma (FNS), also known as facial nerve neuroma/neurilemoma, is a schwannoma that arises from the facial nerve. They are generally uncommon, and when involving the temporal bone, make up less than 1% of all temporal bone tumours. Epidemiology FNS is a rare tumour 2. Clinical...
Article

Fascicular sign

Fascicular sign is a finding on T2-weighted MRI images that suggests a lesion of neurogenic origin. It is characterised by multiple small ring-like structures with peripheral hyperintensity representing the fascicular bundles within the nerves. It is found in various neurogenic tumours, includi...
Article

Fetal cardiac tumours

Fetal cardiac tumours refer to primary cardiac tumours that can present in the in utero population.  Epidemiology Fetal cardiac tumours are rare; the prevalence, reported from autopsy studies of patients of all ages, varies from 0.0017-0.28 % 2. Pathology Known cardiac tumour types that pres...
Article

Fibrinous pericarditis

Fibrinous pericarditis results from fine granular roughening of the pericardium. Clinical presentation Pericardial friction rub may be heard. Pathology Causes viral acute idiopathic tuberculosis pyogenic acute rheumatic fever myocardial infarction: Dressler syndrome chronic renal fail...
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Fibrosarcoma of the breast

Fibrosarcoma of the breast is a type of malignant stromal sarcoma that rarely occurs as a primary tumour within the breast.  Pathology A fibrosarcoma is composed of immature mesenchymal elements surrounded by a collagenous substance. It is a type of breast sarcoma with a predominant “herringbo...
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FIGO staging system

The FIGO staging systems are determined by the International Federation of Gynecology and Obstetrics (Fédération Internationale de Gynécologie et d’Obstétrique). In general, there are five stages: stage 0: carcinoma in situ (common in cervical, vaginal, and vulval cancer) stage I: confined to...
Article

Flare phenomenon (bone scintigraphy)

Flare phenomenon or osteoblastic flare phenomenon refers to interval visualisation of lesions with a sclerotic rim around an initially lytic lesion or sclerosis of lesions previously undetected on radiograph or CT in the setting of follow-up of an oncological patient with other signs of partial ...
Article

Fluorine-18-labeled sodium fluoride

Fluorine-18-labeled sodium fluoride (also known as 18F-NaF or sodium fluoride) is a PET radiotracer used primarily for skeletal imaging. Structure Fluorine-18-labeled sodium fluoride is an ionic compound comprised of a single sodium atom bound to a positron-emitting isotope of fluorine.  Dist...
Article

Focal fatty sparing of the liver

Focal fatty sparing of the liver is a localised absence of fatty change in a liver otherwise affected by fatty change (diffuse hepatic steatosis). Recognition of this finding is useful to prevent falsely thinking the region is a mass. Epidemiology To be added Pathology Similar to its inverse...
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Focal sclerotic bony lesions (mnemonic)

A popular mnemonic to help remember causes of focal sclerotic bony lesions is: HOME LIFE Mnemonic H: healed NOF O: osteoma M: metastasis E: Ewing sarcoma L: lymphoma I: infection or infarct F: fibrous dysplasia E: enchondroma
Article

Follicular lymphoma

Follicular lymphoma is the most common subtype of non-Hodgkin lymphoma (NHL) Epidemiology Estimated to account for ~45% of all NHL cases 1. Higher rates in North America and Europe 4.  Pathology Nodal effacement by closely packed follicles containing small cleaved cells without nucleoli (cen...
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Gastric adenocarcinoma

Gastric adenocarcinoma, commonly referred to as gastric cancer, refers to a primary malignancy arising from the gastric epithelium. It is the most common gastric malignancy.  Epidemiology Gastric cancer is rare before the age of 40, but its incidence steadily climbs after that and peaks in the...
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Gastric cancer (summary)

This is a basic article for medical students and other non-radiologists Gastric cancer, also known as stomach cancer or gastric carcinoma, refers to a cancer that arises from the mucosal lining of the stomach. It is the commonest gastric malignancy. Reference article This is a summary article...
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Generalised osteopenia

Generalised osteopenia refers to osteopenia diffusely affecting the bones. Differential diagnosis The differential diagnosis is wide and includes includes: osteoporosis: decreased osteoid production osteomalacia: undermineralisation of osteoid hyperparathyroidism multiple myeloma diffuse ...
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Germ cell tumours (mnemonic)

A mnemonic for differential diagnosis for germ cell tumours is: SECTE Mnemonic S: seminoma E: embryonal cell carcinoma C: choriocarcinoma T: teratoma E: endodermal sinus tumour (yolk sac tumour)
Article

Giant breast masses

Many patients, particularly in developing countries, can present late with giant breast masses. They may be single or multiple and either benign or malignant. Many of these conditions are indistinguishable on physical examination alone. Some of these lesions require mastectomy while others can b...
Article

Granulocytic sarcoma

Granulocytic sarcoma (also called myeloid sarcoma and chloroma) is a rare neoplasm comprised of myeloid precursor cells. Epidemiology It is typically seen is in children with ~60% occurring in individuals less than 15 years of age. There is no recognised gender predilection. Granulocytic sarc...
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Haemangioblastoma (central nervous system)

Haemangioblastomas are tumours of vascular origin and occur both sporadically and in patients with von Hippel Lindau (vHL). They are WHO grade I tumours that can occur in the central nervous system or elsewhere in the body, including kidneys, liver, and pancreas. These tumours generally present...
Article

Haemorrhage exclusion sign (prostate)

The haemorrhage exclusion sign can be a useful MRI finding following prostate biopsy. Pathology The normal prostate produces high concentrations of citrate, which among other properties, acts as an anticoagulant 1. As tumour cells are dysfunctional, they will produce lower levels of citrate th...
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Haemorrhagic metastases (mnemonic)

A mnemonic for primary malignancies responsible for haemorrhagic metastases is: MR CT BB Mnemonic M: melanoma: metastatic melanoma to brain R: renal cell carcinoma C: choriocarcinoma T: thyroid carcinoma, teratoma B: bronchogenic carcinoma B: breast carcinoma
Article

Head and neck cancer therapy response interpretation (Hopkins criteria)

The head and neck cancer therapy response interpretation (Hopkins criteria) is a qualitative system of interpretation for therapy response assessment using PET-CT. Background Widely used options for therapy response assessment are clinical examination, histopathology, CT  and MR imaging, howev...
Article

Head and neck squamous cell carcinomas

Head and neck squamous cell carcinomas (HNSCC) refer to SCCs of the aerodigestive tract of the head and neck rather than cutaneous SCCs. SCC is the most common tumour of the mucosa of the upper aerodigestive tract, and can occur anywhere there is squamous cell mucosa.  Epidemiology, risk factor...
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Hepatic abscess

Hepatic abscesses, like abscesses elsewhere, are localised collections of necrotic inflammatory tissue caused by bacterial, parasitic or fungal agents.  Epidemiology The frequency of individual infective agents as causes of liver abscesses are intimately linked to the demographics of the affec...
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Hepatic carcinosarcoma

Hepatic carcinosarcoma is a very rare tumour that is defined by mixed histological features.  Terminology This tumour has also been referred to as malignant mixed tumour, spindle cell carcinoma, pseudosarcoma or sarcomatoid carcinoma 1,2.  Pathology Hepatic carcinocarcinoma contain a mixture...
Article

Hepatic metastases

Hepatic metastases are 18-40 times more common than primary liver tumours 6. Ultrasound, CT, and MRI are all useful for detection of hepatic metastases and evaluation across multiple post-contrast CT series, or MRI pulse sequences are necessary.  Epidemiology The demographics of patients with ...
Article

Hepatoblastoma (staging)

As expected there are a number of different staging systems for hepatoblastoma. Staging PRETEXT grouping system of paediatric liver tumours not specific to hepatoblastoma; used in all paediatric liver tumours Intergroup staging system specific for hepatoblastoma (see below) Intergroup stag...
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Hepatomegaly

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

High-grade appendiceal mucinous neoplasms

High-grade appendiceal mucinous neoplasms (HAMN) are rare mucinous tumours of the appendix showing high-grade cytologic atypia, cf. low-grade appendiceal mucinous neoplasms (LAMN). The distinction between both LAMN and HAMN is done on histological grounds and these tumours look the same on imagi...
Article

Histiocytic sarcoma

Histiocytic sarcoma is a rare malignant haematopoietic neoplasm that has been reported in association with other haematological malignancies (particularly B and T cell lymphomas). Pathology It comprises of tumour cells derived from the monocyte/macrophage lineage. Location It usually occurs ...
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HIV associated neoplasms

HIV-associated neoplasms are numerous and can be broadly divided into two groups: AIDS-defining malignancies associated but not AIDS defining malignancies AIDS-defining malignancies The development of these malignancies in HIV affected individuals generally implies progression to AIDS 4: Ka...
Article

Hodgkin lymphoma

Hodgkin lymphoma or Hodgkin disease (HD) is a type of lymphoma and accounts for ~1% of all cancers. HD spreads contiguously and predictably along lymphatic pathways and is curable in ~90% of cases, depending on its stage and sub-type. Epidemiology There is a bimodal distribution in the age of ...
Article

Hodgkin lymphoma (pulmonary manifestations)

Pulmonary manifestations of Hodgkin lymphoma are relatively rare, present in  5-12% of patients at the time of diagnosis. It is relatively more common with the nodular sclerosing subtype. Pulmonary involvement usually indicates stage IV disease.  Radiographic features Bilateral involvement is ...
Article

How you can help build Radiopaedia.org

Contributing to Radiopaedia.org does not need to be a massive commitment. Even a few minutes here and there can make a real difference. This page is a great place to start if you want to get involved. There are many ways to do this: create your own case library and make your existing cases comp...
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Hyperechoic liver lesions

A hyperechoic liver lesion on ultrasound can arise from a number of entities, both benign and malignant. A benign hepatic haemangioma is the most common entity encountered, but in patients with atypical findings or a risk for malignancy, other entities must be considered. Benign hepatic haeman...
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Hypertrophied column of Bertin

Columns of Bertin represent the extension of renal cortical tissue which separates the pyramids, and as such are normal structures. They become of radiographic importance when they are unusually enlarged and may be mistaken for a renal mass (renal pseudotumour). Nomenclature of such enlarged co...
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Hypervascular metastases

There are several tumours which are noted to cause hypervascular metastases. The list of differential diagnoses includes: renal cell carcinoma (RCC) breast cancer: homogeneously hypervascular liver metastases from breast are considered rare 3 lung cancer neuroendocrine tumours carcinoid tum...
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Hypopharyngeal squamous cell carcinoma

Squamous cell carcinoma of the hypopharynx is relatively uncommon, carries the worst prognosis of any head and neck squamous cell carcinoma (HNSCC), and is a challenge to diagnose and treat.  Hypopharyngeal carcinoma is relatively uncommon representing only 10% of all proximal aerodigestive tra...
Article

Hypopharyngeal squamous cell carcinoma (staging)

Staging of hypopharyngeal squamous cell carcinoma is performed using the TNM staging system. TNM staging Primary tumour staging (T) T1: limited to 1 subsite AND tumour size ≤ 2 cm in greatest dimension T2: extends into adjacent subsite or area (larynx, oropharynx) and/or tumour size betw...
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

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...
Article

Incidentaloma

An incidentaloma is a radiological neologism to denote a mass lesion found incidentally and of dubious clinical significance. Although it can refer to any incidental lesion (e.g. pituitary 3, thyroid 4), it is most often used to denote an incidental adrenal lesion, which is commonly an adrenal a...
Article

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...
Article

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 with a characteristic clinical presentation and unique radiographic appearances.  Epidemiology   Inflammatory carcinomas account for 1-...
Article

Intensity modulated radiation therapy (IMRT)

Intensity Modulated Radiation Therapy (IMRT) represents the radiotherapeutic modality where the intensity of the radiation delivered, could be modulated during the treatment to focus on the tumour tissue and spare the adjacent anatomical structures/tissue(s). Therefore the increased dose of radi...
Article

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 are sometimes colloquially referred to as the "grandfather lesion". Main duct ty...
Article

Intradural extramedullary metastases

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

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...
Article

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

Intraventricular masses (an approach)

The ventricular system of the brain plays host to a variety of unique tumours, as well as tumours that are more frequently seen elsewhere (e.g. meningiomas). Besides, some intra-axial (parenchymal) masses can be mostly exophytic and thus appear mostly intraventricular. A systematic approach taki...
Article

Intraventricular meningioma

Intraventricular meningiomas are rare intracranial tumours that represent an uncommon subtype of the more classical extra-axial meningioma and represent between 0.5 and 2% of all meningiomas. Despite its rarity, they represent one of the commonest adult intraventricular neoplasms 4. Epidemiolog...

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