The differential for cystic lesions of the pancreas includes:
intraductal papillary mucinous neoplasms (IPMN)
serous cystadenoma uncommonly uni/macrolocular
pancreatic cysts occur in association with
von Hippel Lindau syndrome
autosomal dominant polycysti...
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 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 dense hilum sign suggests a pathological process at the hilum or in the lung anterior to posterior to the hilum. Malignancy, especially lung cancer, should be suspected.
On a well-centred chest PA radiograph the density of the hilum is comparable on both sides. In the...
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...
Diabetic mastopathy (DMP) is a condition characterized by the presence of 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.
Diabetic mastopathy manifests clinically as a l...
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)
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 t...
Endometrial carcinoma is generally considered the most common gynaecological malignancy 1,5. It frequently presents with vaginal bleeding and both ultrasound and pelvic MRI are useful modalities for evaluation.
Incidence peaks at around the 6th decade, though 12% of cases present ...
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 margin of cortical bones, typically seen in 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 benign aetiology. In fact...
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...
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 ...
Focal fatty sparing of the liver is a localised absence of fatty change in a liver otherwise, affects with 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 inver...
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 a subtype of non-Hodgkin lymphoma (NHL) and is, in fact, the most common type.
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 ce...
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...
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; read more in our article on gastric cancer.
Generalised osteopaenia refers to to osteopaenia 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, 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 be tr...
Granulocytic sarcoma (also called myeloid sarcoma and chloroma) is a rare neoplasm comprised of myeloid precursor cells.
It can occur in association with:
acute myeloid leukaemia (AML)
chronic myeloid leukaemia (CML)
other myeloproliferative disorders such as
myelofibrosis with myeloid meta...
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...
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 than t...
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
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 peliosis is a rare benign vascular condition characterised by dilatation of sinusoidal blood filled spaces within the liver. There may be involvement of other organs, most commonly the spleen and bone marrow. It can be seen in a variety of settings and is important as appearances may m...
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:
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 ...
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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.
A column of Bertin is 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 columns ...
There are several tumours which are noted to cause hypervascular metastases. The list includes:
renal cell carcinoma (RCC)
breast cancer: homogeneously hypervascular liver metastases from breast are considered rare 3
carcinoid tumours 2
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 it's proximity to the optic chiasm, third ventricle and pituitary region, many lesions of these locations ca...
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...
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. Main duct type (see below) appears to present a decade or so earlier on average than bran...
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.
The age at presentation depends on tumour typ...
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.
Inverted papillomas are a type of Schneiderian papilloma. They are uncommon with distinctive pathological and imaging features.
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...
Ischaemic colitis refers to inflammation of the colon secondary to vascular insufficiency and ischaemia. It is sometimes considered under the same spectrum as intestinal ischaemia. The severity and consequences of the disease are highly variable.
Ischaemic bowel is typically a dis...
Ishikawa classification system describes the degree of involvement of adjacent portal vein and SMV by pancreatic ductal adenocarcinoma based on calibre of the vein:
type I: normal
type II: smooth shift/displacement with normal calibre
type III: unilateral narrowing
type IV: bilateral nar...
The ivory vertebra sign refers to diffuse and homogeneous increase in opacity of a vertebral body that otherwise retains its size and contours, and with no change in the opacity and size of adjacent intervertebral discs.
The cause for an ivory vertebra depends on the age o...
Juxtaglomerular cell tumour (JGCT) is an infrequent renal tumour of the juxtaglomerular cells. These cells secrete renin and often cause severe hypertension and hypokalaemia.
JGCT affects all age groups, but is most common in adolescents and young adults, with peak prevalence in t...
Kimura disease is a rare benign inflammatory disease that characteristically manifests as enlargement of cervical lymph nodes and salivary glands.
Kimura disease typically affects males (80%) between 20 and 40 years of age (80% of cases) 1-2, and is most frequently seen in Asia. S...
Lambert-Eaton myasthenia syndrome (LEMS) is rare but is still the second most common neuromuscular junction disease after myasthenia gravis. Two-thirds of LEMS present as a paraneoplastic syndrome secondary to malignancy, most commonly lung cancer but is also associated with breast, ovarian and ...
The skeleton is the most commonly involved organ system in Langerhans cell histiocytosis (LCH) and is by far the most common location for single-lesion LCH, often referred to as eosinophilic granuloma (EG) (the terms are used interchangeably in this article). For a general discussion of this dis...
Laryngeal squamous cell carcinoma staging uses the TNM staging system and actual staging is subsite (see laryngeal subsites) specific for T1-3. A rough approximation for all subsites is
T1: limited to one subsite and normal cord mobility
T2: more than one subsite and impaired cord mobility (bu...
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.
Leptomeningeal enhancement refers to a diffuse or focal gyriform or serpentine enhancement that can be seen in the following conditions:
tuberculous meningitis (can also be focal)
CNS cryptococcal infection
coccidioidal meningitis (c...
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...
Lipoblastoma of the lung is a fat derived thoracic tumour.
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
Lipoblastomas are rare soft-tissue...
Littoral cell angioma of the spleen (LCA) is a rare and relatively recently (1991) described vascular tumour of the spleen.
Littoral cell angiomas may occur at any age and have no gender predilection.
Typically, patients with littoral cell angioma are found...
Mnemonics for the differential diagnosis of lucent/lytic bone lesions include:
They are anagrams of each other and therefore include the same components. They are by no means exhaustive lists, but are a good start for remembering a differential for a lucent/lytic bone...
Lymphangitic carcinomatosis, or lymphangitis carcinomatosa, is the term given to tumour spread through the lymphatics of the lung and is most commonly seen secondary to adenocarcinoma.
The demographics will reflect that of the underlying malignancy (see below).
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.
Lymphoma accounts for ~4% of all cancers 4. T...
There are a number of lymphoma staging systems for both Hodgkin lymphoma and non-Hodgkin lymphoma including the Ann Arbor classification, Cotswolds-modified Ann Arbor classification, and the most current, Lugano classification.
Evolution of lymphoma staging and treatment response evaluation cr...
Male breast disease includes a wide spectrum of conditions. Many conditions and entities that affect the female breast may also affect the male breast.
male breast cancer
pseudogynaecomastia - fat deposition within th...
Malignant biliary tract obstruction (MBTO) represents a group of conditions that cause obstructive jaundice. While most examples are the result of pancreatic head cancers, other malignancies may be causative.
This is a summary article; we do not have a more in-depth reference...
Malignant melanoma is a malignant neoplasm that arises from melanocytes (or cells that derive from melanocytes). Melanocytes predominantly occur in the basal layer of the epidermis and most melanomas, therefore, arise in the skin. However, melanocytes do occur in other locations and can give r...
Malignant pleural disease usually heralds a poor prognosis, whether it represents a primary pleural malignancy or metastatic involvement.
Clinical presentation is variable. Patients may be asymptomatic or have pleuritic pain. If associated with a sizeable pleural effusio...
A number of staging systems have been described for staging of malignant pleural mesothelioma. Below is the International Mesothelioma Interest Group TNM staging system.
T - Tumour
Tx: primary tumour cannot be assessed
T0: no evidence of primary tumour
Mucosa associated lymphoid tissue (MALT) lymphoma, also called extranodal marginal zone B-cell lymphoma, is a type of low-grade extranodal lymphoma.
MALT lymphoma represents ~7.5% of non-Hodgkin lymphomas. Average age of presentation is 60 years with a slight female predominance ...
Mandibular lesions are myriad and common. The presence of teeth results in lesions that are specific to the mandible (and maxilla) and a useful classification that defines them as odontogenic or non-odontogenic. While it may often not be possible to make a diagnosis on imaging alone, this classi...
Mantle cell lymphoma (MCL) is a type of non Hodgkin lymphoma (NHL) and accounts for ~5% of all NHL. It is a malignant neoplasm of virgin B cells that closely resemble normal mantle zone B cells surrounding germinal centres.
They occur in older adults (mean age ~60 years). There is...
The Masaoka staging system is commonly adopted for thymomas 1-3, and is the most important determinant of survival following surgical resection 4:
stage I: intact thymic capsule
stage II: capsular invasion into adjacent mediastinal fat or pleura
stage III: macroscopic invasion into adjacent o...