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.
adenomatous colon polyps
villous colon polyps
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...
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%.
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.
Gray-level frequency distribution: pixel intensity histogra...
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...
A congenital neuroblastoma is defined as neuroblastoma identified within a month of birth, and is divided into :
In most cases they present as stage 1, 2 or 4S (see neuroblastoma staging).
In 90% of cases fetal neuroblastomas ar...
A handy mnemonic to recall cortically-based brain tumours is:
P: pleomorphic xanthoastrocytoma
D: dysembryoplastic neuroepithelial tumour (DNET); desmoplastic infantile astrocytoma and ganglioglioma
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...
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...
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...
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.
These metastases can come from haematogenous or lymphatic spread, ...
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
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.
The main challenge in discri...
The differential for cystic lesions of the pancreas includes:
intraductal papillary mucinous neoplasm (IPMN)
serous cystadenoma uncommonly uni/macrolocular
simple pancreatic cyst
pancreatic cysts occur in association with
von Hippel Lindau syndrome
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...
Cystic or necrotic appearing lymph nodes can be caused by a number of infectious, inflammatory or malignant conditions:
squamous cell carcinoma metastases
plasmacytoid T-cell leukemia
acute myeloid leukemia
herpes simplex lymphadenit...
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.
It has been reported with many ...
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).
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...
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.
On a well-centred chest posteroanterior (PA) radiograph the density of the hilum is comparable on ...
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.
The tumour occurs in patients of...
Dermatomyositis is an autoimmune inflammatory myositis.
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...
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.
The terms desmoid tumour and aggressive fibromatosis are occasionally used synonymously b...
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.
Incidence is ~0.3%. The most common areas of involve...
Desmoplastic small round cell tumours are a rare and highly aggressive primary peritoneal malignancy.
They are usually seen in young adolescents and has male predominance with a mean survival of 2-3 years.
It usually presents with a palpable abdominal mass ...
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...
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 ...
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...
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...
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
3 M's PROOF
metastases (osteoblastic metastases)
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...
A diffuse homogeneous bone marrow FDG uptake usually reflects hyperplastic bone marrow which can be seen in the following conditions:
granulocyte colony stimulating factor (G-CSF)
A ductal adenoma of the breast is a benign glandular tumour of the breast that usually fills and distends the ductal lumen.
They may occur in women of all ages, although the majority of patients are 60 years of age or greater 3.
Ductal adenomas usually pres...
Duodenal filling defects may be caused by a wide variety of duodenal pathology which may be divided by their location and pathological process.
common bile duct impression
Note: please refer to duodenal mucosal nodular fill...
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.
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...
Dysplastic liver nodules are focal nodular regions (≥ 1 mm) without definite evidence of malignancy.
They have been found in cirrhotic patients with a prevalence of 14% (size >1.0 cm) to 37% (size >0.5 cm) 2.
increased fat or glyco...
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...
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.
Incidence peaks at around the 6th decade, though 12% of cases present in ...
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.
Endometrial hyperplasia affects women of a...
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...
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...
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...
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.
FNS is a rare tumour 2.
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...
Fetal cardiac tumours refer to primary cardiac tumours that can present in the in utero population.
Fetal cardiac tumours are rare; the prevalence, reported from autopsy studies of patients of all ages, varies from 0.0017-0.28 % 2.
Known cardiac tumour types that pres...
Fibrinous pericarditis results from fine granular roughening of the pericardium.
Pericardial friction rub may be heard.
acute rheumatic fever
myocardial infarction: Dressler syndrome
chronic renal fail...
Fibrosarcoma of the breast is a type of malignant stromal sarcoma that rarely occurs as a primary tumour within the breast.
A fibrosarcoma is composed of immature mesenchymal elements surrounded by a collagenous substance. It is a type of breast sarcoma with a predominant “herringbo...
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...
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 ...
Fluorine-18-labeled sodium fluoride (also known as 18F-NaF or sodium fluoride) is a PET radiotracer used primarily for skeletal imaging.
Fluorine-18-labeled sodium fluoride is an ionic compound comprised of a single sodium atom bound to a positron-emitting isotope of fluorine.
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.
To be added
Similar to its inverse...
A popular mnemonic to help remember causes of focal sclerotic bony lesions is:
H: healed NOF
E: Ewing sarcoma
I: infection or infarct
F: fibrous dysplasia
Follicular lymphoma is the most common subtype of non-Hodgkin lymphoma (NHL)
Estimated to account for ~45% of all NHL cases 1. Higher rates in North America and Europe 4.
Nodal effacement by closely packed follicles containing small cleaved cells without nucleoli (cen...
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.
Gastric cancer is rare before the age of 40, but its incidence steadily climbs after that and peaks in the...
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.
This is a summary article...
Generalised osteopenia refers to osteopenia diffusely affecting the bones.
The differential diagnosis is wide and includes includes:
osteoporosis: decreased osteoid production
osteomalacia: undermineralisation of osteoid
A mnemonic for differential diagnosis for germ cell tumours is:
E: embryonal cell carcinoma
E: endodermal sinus tumour (yolk sac tumour)
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...
Granulocytic sarcoma (also called myeloid sarcoma and chloroma) is a rare neoplasm comprised of myeloid precursor cells.
It is typically seen is in children with ~60% occurring in individuals less than 15 years of age. There is no recognised gender predilection.
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...
The haemorrhage exclusion sign can be a useful MRI finding following prostate biopsy.
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...
A mnemonic for primary malignancies responsible for haemorrhagic metastases is:
MR CT BB
M: melanoma: metastatic melanoma to brain
R: renal cell carcinoma
T: thyroid carcinoma, teratoma
B: bronchogenic carcinoma
B: breast carcinoma
The head and neck cancer therapy response interpretation (Hopkins criteria) is a qualitative system of interpretation for therapy response assessment using PET-CT.
Widely used options for therapy response assessment are clinical examination, histopathology, CT and MR imaging, howev...
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...
Hepatic abscesses, like abscesses elsewhere, are localised collections of necrotic inflammatory tissue caused by bacterial, parasitic or fungal agents.
The frequency of individual infective agents as causes of liver abscesses are intimately linked to the demographics of the affec...
Hepatic carcinosarcoma is a very rare tumour that is defined by mixed histological features.
This tumour has also been referred to as malignant mixed tumour, spindle cell carcinoma, pseudosarcoma or sarcomatoid carcinoma 1,2.
Hepatic carcinocarcinoma contain a mixture...
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.
The demographics of patients with ...
As expected there are a number of different staging systems for hepatoblastoma.
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)
Hepatomegaly refers to an increase in size or enlargement of the liver.
Hepatomegaly can result from a vast range of pathology including, but not limited to, the following:
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...
Histiocytic sarcoma is a rare malignant haematopoietic neoplasm that has been reported in association with other haematological malignancies (particularly B and T cell lymphomas).
It comprises of tumour cells derived from the monocyte/macrophage lineage.
It usually occurs ...
HIV-associated neoplasms are numerous and can be broadly divided into two groups:
associated but not AIDS defining malignancies
The development of these malignancies in HIV affected individuals generally implies progression to AIDS 4:
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.
There is a bimodal distribution in the age of ...
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.
Bilateral involvement is ...
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...
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.
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...
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
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...
Staging of hypopharyngeal squamous cell carcinoma is performed using the TNM staging system.
Primary tumour staging (T)
limited to 1 subsite AND
tumour size ≤ 2 cm in greatest dimension
extends into adjacent subsite or area (larynx, oropharynx) and/or
tumour size betw...
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...
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.
They are considerably less common than mature ovar...
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...
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.
Patient can present with many features which include
bilateral pedal oede...
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.
Inflammatory carcinomas account for 1-...
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...
Intraductal papillary mucinous neoplasms or tumours (IPMNs or IMPTs) are cystic tumours of the pancreas.
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...
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.
The age at presentation depends on tumour type...
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
direct extension from leptomeninges
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.
It is important to note that it has been argued by some ...
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...
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.