Gallbladder carcinomas are usually asymptomatic until they reach an incurable stage. As such, early incidental detection is important, if the occasional patient is to be successfully treated. The majority (90%) are adenocarcinomas, and the remainder is squamous cell carcinomas.
Gastrointestinal stromal tumours (GIST) are the most common mesenchymal tumours of the gastrointestinal tract. They account for ~5% of all sarcomas. They respond remarkably well to chemotherapy.
Previously these tumours have been variably referred to as leiomyomas, leiomyosarcomas...
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 ...
Paragangliomas, sometimes called glomus tumours, are rare neuroendocrine tumours arising from paraganglia.
Paraganglia are clusters of neuroendocrine cells dispersed throughout the body and closely related to the autonomic nervous system, with either parasympathetic or sympathetic...
Carney-Stratakis syndrome is a rare autosomal dominant condition comprising of familial paraganglioma and gastric stromal sarcoma.
It is considered to be distinct from, but perhaps related to, the Carney triad 1. Neither should be confused with the unrelated Carney complex.
Peritoneal metastases are a relatively common location for metastases, particularly from tumours of the abdomen and pelvis, that generally imply a poor prognosis, often with a significant impact on palliation 1.
If peritoneal metastases are of an epithelial origin (as most are) and...
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:
Adrenal metastases are the most common malignant lesions involving the adrenal gland. Metastases are usually bilateral but may also be unilateral. Unilateral involvement is more prevalent on the left side (ratio of 1.5:1).
They are present at autopsy in up to 27% of patients with ...
The anatomy curriculum is one of our curriculum articles and aims to be a collection of articles that represent the core anatomy knowledge for radiologists and imaging specialists.
Head and neck anatomy
Abdominal and pelvic anatomy
An adrenal collision tumour or collision tumour of the adrenal gland is an uncommon condition where two histologically distinct tumours abut each other or are in close proximity in the same adrenal gland.
Collision tumours have been reported in nearly every organ, for example, collis...
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...
Choroid plexus malignancies can be classified as primary or secondary neoplasms of the choroid plexus:
choroid plexus papilloma (CPP)
WHO Grade I, and WHO Grade II when atypical
choroid plexus carcinoma (CPC)
WHO Grade III
Splenic metastases are relatively rare on imaging, although they are more commonly found on autopsy. Typically they are part of a widespread metastatic disease.
The rate of splenic metastases varies between 1-10% of autopsy studies, depending on whether microscopic or macroscopic ...
CA 27-29 is a tumour marker and is a soluble form of glycoprotein MUC1. It may be elevated in patients with breast cancer. Tumours of the colon, stomach, kidney, lung, ovary, pancreas, uterus, and liver may also raise CA 27-29 levels.
Certain non-malignant conditions are also associated with it...
Preinvasive lesions for lung adenocarcinoma are a category of small noninvasive lung lesions which are closely related to adenocarcinoma of the lung. They may represent a spectrum of premalignant to low-grade malignant lesions.
The category includes two types of lesions:
atypical adenomatous h...
Clear cell sarcomas of the kidney (CCSK) are a rare mesenchymal renal tumour that account for ~5% of primary renal neoplasms in the paediatric population 1.
Clear cell sarcoma of the kidney is the second most common primary malignant paediatric renal neoplasm after Wilms tumour, ...
Pancreatic calcifications can arise from many aetiologies.
Punctate intraductal calcifications
alcoholic pancreatitis (20-40%) 2
intraductal, numerous, small, irregular
preponderant cause of diffuse pancreatic intraductal calcification
gallstone pancreatitis (2%) 2
Adenocarcinoma of the lung is one of the non-small cell carcinomas of the lung and is a malignant tumour with glandular differentiation or mucin production. This tumour exhibits various patterns and degrees of differentiation, including lepidic, acinar, papillary, micropapillary, and solid with ...
Primary pulmonary lymphomas refer to clonal lymphoid proliferation affecting the lungs without any detectable extrapulmonary involvement. It is much rarer than secondary pulmonary lymphoma and is most frequently represented by lymphoma of B-cell lineage - often marginal zone B-cell lymphoma of m...
There are many types of breast neoplasms, which can be divided into the following broad oversimplified categories as a starting point.
intralobular (epithelial and stromal)
metastasis to breast
Intralobular and interlobular refer to the terminal duct lobular un...
Adenocarcinoma in situ (AIS) of the lung refers to a relatively new entity for a pre-invasive lesion in the lung. This entity partly replaces the noninvasive end of the previous term bronchoalveolar carcinoma. Adenocarcinoma in situ is defined as a localised adenocarcinoma of <3 cm that exhibits...
Ultrasound appearance of liver metastases can have bewildering variation, and the presence of hepatic steatosis can affect the sonographic appearance of liver lesions.
Patterns do exist between ultrasound appearance of the liver metastases and the likely prima...
Leptomeningeal metastases, also know as carcinomatous meningitis, refers to the spread of malignant cells through the CSF space. These cells can be originated both in primary CNS tumours (e.g. drop-metastases), as well as from distant tumours that have metastasised via haematogenous spread.
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.
Pineal gland metastases are rare and mostly related to primary carcinomas of the lungs, breast, gastrointestinal tract, kidneys and bladder 4. They usually occur concomitantly with leptomeningeal metastases.
This article will discuss metastatic lesions affecting only the pineal gland. For oth...
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
Pleural metastases are one of the vast majority of malignant lesions of the pleura.
The infiltration of the pleura usually manifests as pleural effusion, which is the first manifestation of pleural metastasis. In addition to the symptoms and systemic manifestations of neo...
Vertebral metastases represent the secondary involvement of the vertebral spine by haematogenously-disseminated metastatic cells. They must be included in any differential diagnosis of a bone lesion in a patient older than 40 years.
This article will focus only on the metastasis involving the b...
The Deauville five-point scale (Deauville 5ps) is an internationally-recommended scale for routine clinical reporting 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).
Orbital metastases are relatively uncommon, but some primary tumours do have a predilection to metastasise to the orbit.
This article concerns itself with extraocular metastases, rather than intraocular tumours or direct extension of tumours from neighbouring regions. For a discussion of intrao...
Common brain tumours in infancy (i.e. under one year of age) are quite different from those of brain tumours in adulthood. Most are located in the supratentorial region (~65%) and they carry a poor prognosis.
The frequency of these tumours varies according to studies, but the most common brain ...
Papillary carcinoma of the breast is a rare ductal breast malignancy.
They are thought to account for 1-2% of breast carcinomas 2. They typically present in postmenopausal patients with the mean age at being ~63-67 years.
A papillary carcinoma may manifest ...
Primary hepatic lymphoma (PHL) is rare accounting for roughly 100 described cases. If it is being considered as a diagnosis, distal lymphadenopathy, splenomegaly, bone marrow disease, and leukaemia should not be present for at least 6 months after the liver tumour is detected (see: secondary hep...
Sinonasal lymphoma refers to the involvement of the nasal cavity and/or paranasal sinuses with lymphoma. It can be primary or secondary.
Presenting symptoms of sinonasal lymphoma are variable but are usually similar to those of benign inflammatory diseases. The clinical s...
Muscle lymphoma is a rare manifestation of lymphoma.
Muscle lymphoma is rare, representing <2% of all lymphomas. The average age of presentation is 70 years 1.
Focal swelling and/or pain along with B-type symptoms 2. Any muscle can be involved but most comm...
Pseudocirrhosis is a radiological term used to recapitulate imaging findings of cirrhosis, but occurring in the setting of hepatic metastases. It is most commonly reported following chemotherapeutic treatment of breast cancer metastases, although has also been reported before treatment, and with...
Extramedullary haematopoiesis is a response to the failure of erythropoiesis in the bone marrow.
This article aims to a general approach on the condition, for a dedicated discussion for a particularly involved organ, please refer to the specific articles on:
extramedullary haematopoiesis in t...
Lymph node enlargement (rarely lymphadenomegaly) is often used synonymously with lymphadenopathy, which is not strictly correct.
Lymphadenopathy (or adenopathy) is, if anything, a broader term, referring to any pathology of lymph nodes, not necessarily resulting in increased size; ...
A solitary pulmonary nodule, according to the Nomenclature Committee of the Fleischner Society, is defined as a rounded opacity, well or poorly-defined on a conventional radiograph, measuring up to 3 cm in diameter and is not associated with lymphadenopathy, atelectasis, or pneumonia.
Pure ground glass lung nodules are a subtype of ground glass lung nodules where there is no associated solid component.
They have been shown to represent various pathologies such as 1,3
adenocarcinoma in situ of lung
minimally-invasive adenocarcinoma of lung
invasive adenocarcinoma of lung
Waldenström macroglobulinaemia, previously also known as lymphoplasmacytic lymphoma, is a type of B-cell lymphoma.
Recent publications classify Waldenström macroglobulinaemia as a lymphoplasmacytic lymphoma with any level of an IgM paraprotein 10. Therefore the two entities are no...
Bing-Neel syndrome is an extremely rare neurological complication of Waldenström macroglobulinemia where there is malignant lymphocyte infiltration into the central nervous system (CNS).
The exact incidence is unknown, however in one study of patients with Waldenström macroglobuli...
Inflammatory carcinomas of the breast also referred to 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...
Juxtaglomerular cell tumour (JGCT) is an infrequent renal tumour of the juxtaglomerular cells. These cells secrete renin and often cause severe hypertension and hypokalaemia.
Juxtaglomerular cell tumour affects all age groups, but is most common in adolescents and young adults, wi...
Sweet syndrome (acute febrile neutrophilic dermatosis) is characterised by a constellation of clinical symptoms, physical features, and pathologic findings which include:
tender erythematous skin lesions (papules, nodules, and plaques)
a diffuse infiltrate consisting predo...
68Ga-DOTATATE is a PET radiotracer that is useful for evaluating primary and metastatic well-differentiated neuroendocrine tumours. It is a form of somatostatin-receptor (SSTR) functional imaging and most often combined with cross-sectional imaging in the form of PET/CT.
BALT lymphoma is an abbreviated term for bronchus-associated lymphoid tissue lymphoma. These neoplasms fall under the broader umbrella of mucosa associated lymphoid tissue (MALT) lymphomas. It is sometimes considered a type of primary pulmonary lymphoma.
Up to half of pat...
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 evi...
CA-125 is a high-molecular-weight glycoprotein found on the surface of Mullerian and coelomic epithelial-derived cell types, and is the best known tumour marker for epithelial ovarian cancer 6. Importantly, it may also be elevated in several other conditions (see differential diagnosis section b...
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...
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...
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 (alpha fetoprotein)
Peripheral pulmonary carcinoid tumour refer to a subtype of pulmonary carcinoid tumours that arise within the periphery of the lung. They are considered less common than the more centrally-located bronchial carcinoid tumours.
Many patients tend to be asymptomatic 2. Pre...
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...
Testicular lymphoma is an uncommon testicular malignancy. Lymphoma can involve the testes in three ways:
primary site of extranodal disease (primary testicular lymphoma)
secondary involvement of systemic disease
primary manifestation of subclinical systemic disease
This article is concerned ...
Brain metastases are estimated to account for approximately 25-50% of intracranial tumours in hospitalised patients. Due to great variation in imaging appearances, these metastases present a common diagnostic challenge which can importantly affect the management approach for individual patients....
Typhlitis, also called caecitis or neutropaenic colitis, is a necrotising inflammatory condition which typically involves the caecum and, sometimes, can extend into the ascending colon or terminal ileum.
Typhlitis was first described in children with leukaemia and severe neutropae...
Phaeochromocytomas 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
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).
Malignant transformation is the term given to the process whereby either normal, metaplastic, or benign neoplastic tissue, becomes a cancer. The process usually occurs in a series of steps and the affected tissue gradually accumulates the genetic mutations that express a malignant phenotype. The...
Skeletal muscle metastases are uncommon compared to other sites and are generally seen in the context of widespread metastatic disease.
Post-mortem rates of skeletal metastases vary between 0.03% and 17% 1.
Most commonly asymptomatic 2,3.
Primary pleural lymphoma is extremely rare, especially in immunocompetent patients.
Primary pleural lymphoma accounts for <0.5% of all non-Hodgkin lymphoma 2 and ~2.5% of primary chest wall tumours 4.
Primary pleural lymphoma may be Hodgkin or non-Hodgkin lymphoma wit...
Von Hippel-Lindau (vHL) disease is characterised by the development of numerous benign and malignant tumours in different organs (at least 40 types 1) due to mutations in the VHL tumour suppressor gene on chromosome 3.
The disease is rare with an estimated prevalence of 1:35,000-5...
Pancreatic ductal adenocarcinoma makes up the vast majority (~90%) of all pancreatic neoplasms and remains a disease with a very poor prognosis and high morbidity.
On imaging, it usually presents as a hypodense mass on CT that is poorly marginated, which may encase vessels and the common biliar...
Cannonball metastases refer to large, well circumscribed, round pulmonary metastases that appear, well, like cannonballs. The French term "envolée de ballons" which translates to "balloons release" is also used to describe this same appearance.
Metastases with such an appearance are classically...
An incidentaloma is a radiological neologism to denote a 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 adenom...
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
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...
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...
Adrenal calcification is not a rare finding in healthy asymptomatic people and is usually the result of previous haemorrhage or tuberculosis. Addison disease patients only occasionally develop calcification.
sepsis: Waterhouse-Friderichsen syndrome
Exophytic is a descriptive term used by radiologists/pathologists to describe solid organ lesions arising from the outer surface of the organ of origin.
Literally exophytic only refers to those lesions arising from the outer surface, however radiologists and pathologists use the term to include...
Pulmonary metastases are common and the result of metastatic spread from a variety of primary tumours via blood or lymphatics.
This article describes haematogenous pulmonary metastases with lymphangitis carcinomatosis discussed separately.
The epidemiology will match that of the ...
Choriocarcinoma is an aggressive, highly vascular tumour. When it is associated with gestation, it is often considered part of the spectrum of gestational trophoblastic disease; it is then termed gestational choriocarcinoma. When it occurs in the absence of preceding gestation, it is termed non-...
Smoking related lung diseases are the respiratory manifestations of disease that is related to smoking. Smoking affects the lungs in numerous ways, and can be classified under the following headings:
smoking related interstitial lung diseases (SR-ILD)
Endometrial hyperplasia is abnormal proliferation of the endometrial glands and stroma, defined as diffuse smooth thickening >10 mm 13. One of the main concerns is the potential malignant transformation of the endometrial hyperplasia to endometrial carcinoma.
Pelvic masses in females carry a broad differential diagnosis:
benign adnexal cyst: 34%
pelvic malignancy: 14%
pelvic inflammatory disease: 8%
Extra-gynaecological masses, e.g. colorectal carcino...
Positron Emission Tomography Response Criteria in Solid Tumors (PERCIST) make use of positron emission tomography (PET) to provide functional information to help determine tumour viability.
The criteria consist of four categories: complete metabolic response (CMR), partial metabolic response (P...
Tumours of the male urethra are uncommon. They can be categorised both on the grounds of histology and location.
squamous cell carcinoma of the urethra: 80%
urothelial/transitional cell carcinoma of the urethra: 15% (predominantly posterior urethra)
adenocarcinoma of the urethra: 5...
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
Burkitt lymphoma is an aggressive B-cell lymphoma predominantly affecting children.
Burkitt lymphoma is the most common (40%) type of non-Hodgkin lymphoma in childhood. Median age is eight years with a male predominance (M:F = 4:1) 1. It is less common in adults, accounting for 1-...
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. The average age of presentation is 60 years with a slight female predomina...
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).
Nasopharyngeal carcinoma accounts for ~70% of all primary malignancies of the na...
Thyroid-associated orbitopathy (TAO) is the most common cause of proptosis in adults and is most frequently associated with Graves disease.
On imaging, it is characterised by enlargement of the extraocular muscles' bellies (frequently: inferior rectus > medial rectus > superior rectus) sparing...
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...
Lymphadenopathy is quite common, and it can be very difficult to differentiate malignant lymphadenopathy from reactive nodal enlargement.
Several gray scale and colour Doppler features favour malignancy in a lymph node.
Gray scale parameters that favour malignancy
size: larger-more likely mal...
Radiation-induced heart disease, also known as radiation cardiotoxicity, describes an uncommon constellation of potential cardiac complications of mediastinal radiotherapy.
The demographics of patients affected by radiation-induced heart disease are those of the underlying conditi...
The appearance of multiple, well-defined lytic lesions (punched out lesions) of various size scattered throughout the skull constitutes the raindrop skull appearance of multiple myeloma. This term is applied as an analogy to rain hitting a surface and splashing, where it leaves a random pattern ...
The 2005 WHO histological classification of odontogenic tumours lays out a classification system for neoplasms and other tumours related to the odontogenic apparatus. At the time of writing (2016), it is still the most widely used classification system although a new revision is due to come up i...
Adenomatoid odontogenic tumours are rare and differ from most other dentition related lesions in that they more frequently occur in the maxilla.
They are also seen more frequently in females, most frequently in the second decade of life.
They present as an ...
Radiation-induced pulmonary fibrosis is the late manifestation of radiation-induced lung disease (RILD) and is relatively common following radiotherapy for chest wall or intrathoracic malignancies.
This article does not deal with changes seen in the acute phase. Please refer to the article on r...
Response assessment in neuro-oncology criteria (RANO), published in 2010 1, are used to assess response to first-line treatment of glioblastoma (as well as lower grade astrocytoma 3) and have largely superseded the older Macdonald criteria (which only dealt with glioblastoma multiforme) 2.
Protoplasmic astrocytoma is a rare variant of diffuse low-grade astrocytomas with histological and imaging features which overlap with other entities.
Until recently they were classified as a subtype of low-grade diffuse astrocytoma, however, in the latest (2016) update to WHO classification o...
Thymic hyperplasia is a disorder whereby there is hyperplasia of the thymus gland.
Thymus hyperplasia can be subdivided into two forms:
true thymic hyperplasia
Both true thymic hyperplasia and lymphoid hyperplasia manifest as diffuse symmetric enlargement of...