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...
Gastric lymphoma may either represent secondary involvement by systemic disease or primary malignancy confined to the stomach.
Gastric lymphoma represents the most common site of extranodal lymphoma, accounting for 25% of all such lymphomas, 50% of all gastrointestinal lymphomas...
Gastric metastases are rare, found in less than 2% of patients who die of a carcinoma 6.
Usually affects the middle-aged and elderly population. Affects males and females equally without predilection.
The patient may be asymptomatic, but the most common sig...
Gastrointestinal stromal tumors (GIST) are the most common mesenchymal tumors of the gastrointestinal tract. They account for ~5% of all sarcomas. They respond remarkably well to chemotherapy.
Previously these tumors have been variably referred to as leiomyomas, leiomyosarcomas, a...
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 tumors is:
E: embryonal cell carcinoma
E: endodermal sinus tumor (yolk sac tumor)
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...
Giant cell tumors of bone, also known as osteoclastomas, are relatively common bone tumors and are usually benign. They typically arise from the metaphysis of long bones, extend into the epiphysis adjacent to the joint surface, and have a narrow zone of transition.
Giant cell tumo...
The Gynecologic Imaging Reporting and Data System (GI-RADS) is a reporting system that was created for reporting the findings in adnexal masses based on transvaginal ultrasonography.
Findings are classified into five categories 1:
normal ovaries identified and no adn...
Hemangioblastomas are tumors of vascular origin and occur both sporadically and in patients with von Hippel Lindau (vHL). They are WHO grade I tumors that can occur in the central nervous system or elsewhere in the body, including kidneys, liver, and pancreas.
These tumors generally present on ...
Haemophagocytic lymphohistiocytosis (HLH), also known as macrophage activation syndrome when occurring in the setting of a rheumatologic disorder, is a non-malignant but often-fatal disorder of immune dysregulation affecting multiple organs.
It typically affects infants and young ...
The hemorrhage 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 tumor cells are dysfunctional, they will produce lower levels of citrate than...
A mnemonic for primary malignancies responsible for hemorrhagic 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
Hand-foot syndrome, also known as palmar-plantar erythrodysaesthesia or Burgdorf reaction, is a benign, aseptic, self-limiting complication of many chemotherapeutic agents characterized by a widespread erythema, edema and ulceration of the hands and feet.
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 squamous cell carcinoma (SCC) of the aerodigestive tract of the head and neck, as opposed to cutaneous SCC. They are the most common tumor of the head and neck region, and can arise from any structure with squamous cell mucosa.
HNSCC is c...
Hepatic carcinosarcoma is a very rare tumor that is defined by mixed histological features.
This tumor has also been referred to as malignant mixed tumor, spindle cell carcinoma, pseudosarcoma or sarcomatoid carcinoma 1,2.
Hepatic carcinocarcinoma contain a mixture of...
Hepatic epithelioid hemangioendothelioma (HEHE) is a rare, low to intermediate grade malignant hepatic vascular tumor.
There may be a greater female incidence (with reported male-to-female ratio, 3:2), with peak incidence thought to be around 30-40 years old.
Hepatic metastases are 18-40 times more common than primary liver tumors 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 l...
As expected there are a number of different staging systems for hepatoblastoma.
PRETEXT grouping system of pediatric liver tumors
not specific to hepatoblastoma; used in all pediatric liver tumors
Intergroup staging system
specific for hepatoblastoma (see below)
Intergroup staging ...
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:
Hickman catheters (or Hickman lines) are a type of tunnelled central venous access device.
chemotherapy administration 2
parenteral nutrition 2
long-term parenteral antibiotic administration 2
arrhythmia (most common) 1
High-grade appendiceal mucinous neoplasms (HAMN) are rare mucinous tumors 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 tumors look the same on imaging...
Histiocytic sarcoma is a rare malignant hematopoietic neoplasm that has been reported in association with other haematologic malignancies (particularly B and T cell lymphomas).
It comprises of tumor cells derived from the monocyte/macrophage lineage.
It usually occurs in l...
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 hemangioma is the most common entity encountered, but in patients with atypical findings or a risk for malignancy, other entities must be considered.
Hyperparathyroidism-jaw tumor syndrome is an extremely rare condition where a gene mutation results in hyperparathyroidism in association with both benign and malignant tumors, most notably, tumors in the mandible or maxilla 2.
Approximately 200 cases have been reported in the med...
Hypertrophic osteoarthropathy is a syndrome characterized by periosteal reaction of the long bones without underlying bone lesion. There are a broad range of manifestations, although typically there is symmetrical involvement of the appendicular skeleton. Accompanying abnormal soft tissue prolif...
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 tumors 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
A useful mnemonic to remember tumors which cause hypervascular metastases is:
MR CT PET
R: renal cell carcinoma
T: thyroid carcinoma
PET: (pancreatic) neuroendocrine tumor
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 tumor staging (T)
limited to 1 subsite AND
tumor size ≤ 2 cm in greatest dimension
extends into adjacent subsite or area (larynx, oropharynx) and/or
tumor size between...
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 tumors. They differ from mature ovarian teratomas (dermoid cysts) both histologically by the presence of immature tissue, and clinically by their more malignant behavior.
They are considerably less common than mature ovaria...
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...
Indocyanine green (ICG) lymphangiography is an emerging imaging technique used to visualize lymphatic channels and map their course as they drain to sentinel lymph nodes.
Indocyanine green is a fluorescent dye discovered by researchers at Kodak working on near-infrared photography in ...
Infantile fibrosarcoma of the lung, also known as primary bronchopulmonary fibrosarcoma, is a very rare spindle-cell tumor.
More than 80% of cases are reported to occur within the 1st year of life. There is a slight predominance in male infants 1,2.
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 tumor thrombus.
Patient can present with many features which include
bilateral pedal edema...
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 fo...
Inflammatory myofibroblastic tumors of the spleen are rare spindle cells tumors of indeterminate clinical behavior. Please refer to the article on inflammatory myofibroblastic tumors for a broad discussion on the subject.
They usually present as a well define...
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 tumor tissue and spare the adjacent anatomical structures/tissue(s). Therefore the increased dose of radia...
Intracranial metastatic melanoma is the third most common brain metastasis.
For a broad discussion about the primary tumor or brain metastasis in general, please refer to the articles:
A population-based study of 169,444 cancer patients f...
Intraductal papillary mucinous neoplasms or tumors (IPMNs or IMPTs) are cystic tumors of the pancreas.
These tumors 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 type ...
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 tumor 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 to as primary intraosseous meningioma, is a rare subtype of meningioma that accounts for less than 1% of all osseous tumors. They are the most common type of primary extradural meningiomas 6.
It is important to note that it has been argued by ...
The ventricular system of the brain plays host to a variety of unique tumors, as well as tumors 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 taking...
Intraventricular meningiomas are rare intracranial tumors 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.
Intraventricular neoplasms are rare and arise from periventricular structures such as the walls of the ventricular system, the septum pellucidum and the choroid plexus. Many tumor types arise from, or can bulge into the ventricular system, although there are certain lesions that are relatively r...
Invasive ductal carcinoma is a subset of ductal carcinoma. It is an infiltrating, malignant and abnormal proliferation of neoplastic cells in the breast tissues. It is the most frequently seen breast malignancy.
Peak age of presentation is about 50 to 60 years.
Infiltrating or invasive lobular carcinoma (ILC) of the breast is the second most common type of invasive breast cancer after invasive ductal carcinoma (IDC) "not otherwise specified" (NOS).
They represent 5-10% of all breast cancer. The mean age at presentation may be higher than...
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...
This is a basic article for medical students and other non-radiologists.
Hemoptysis is the coughing up of frank blood or blood-stained mucus/pus from the lungs and it is an important indicator of pathology. Careful assessment of history, clinical examination and investigations will help elicit ...
Iodine-131 (131I or I-131) is a radioisotope of iodine, which is used in the diagnosis and treatment of thyroid lesions. It is one of the oldest radiotracers used in nuclear medicine, in use for over 50 years. It is predominately used in thyroid ablation therapy, for patients post-thyroidectomy...
Ischemic colitis refers to inflammation of the colon secondary to vascular insufficiency and ischemia. It is sometimes considered under the same spectrum as intestinal ischemia. The severity and consequences of the disease are highly variable.
Ischemic bowel is typically a disease...
Ishikawa classification system describes the degree of involvement of adjacent portal vein and SMV by pancreatic ductal adenocarcinoma based on caliber of the vein:
type I: normal
type II: smooth shift/displacement with normal caliber
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 of...
Jugulodigastric lymph nodes, also known as subdigastric lymph nodes, are deep cervical nodes located below the posterior belly of the digastric muscle and anterior to the internal jugular vein.
They are located in neck node level IIa and receive lymphatic drainage from the tonsils, pharynx, ora...
Juxtacortical chondromas, also known as periosteal chondromas, are rare benign chondral tumors that arise from the periosteum of tubular bones. They are thought to account for ~2% of benign bone tumors.
They tend to present around the 2nd to 4th decades. There is a recognised male...
Juxtaglomerular cell tumor (JGCT) is an infrequent renal tumor of the juxtaglomerular cells. These cells secrete renin and often cause severe hypertension and hypokalemia.
Juxtaglomerular cell tumor affects all age groups, but is most common in adolescents and young adults, with p...
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...
The Krenning score is a proposed semi-quantitative method of assessing the degree of tracer uptake on octreotide scintigraphy.
Initially designed for assessment of 111In-DTPA on planar imaging, the Krenning score is applicable to SPECT or SPECT/CT using various radiopharmaceuticals....
This article lists a series of labelled imaging anatomy cases by system and modality.
CT head: non-contrast axial
CT head: non-contrast coronal
CT head: non-contrast sagittal
CT head: angiogram axial
CT head: angiogram coronal
CT head: angiogram sagittal
MR head: T2 axial
Lambert-Eaton myasthenic syndrome (LEMS) is a rare neuromuscular junction disorder of paraneoplastic or primary autoimmune etiology.
LEMS is the second most common neuromuscular junction disease after myasthenia gravis.
Two-thirds of LEMS present as a paraneoplastic syndrome sec...
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...
Large-cell lung cancer is one of the histological types of non-small-cell carcinomas of the lung.
It is thought to account for approximately 10% of bronchogenic carcinoma 1.
Patients present with dyspnea, chronic cough and hemoptysis.
Large cell neuroendocrine carcinoma (LCNEC) of the lung is classified as a subtype of large cell carcinoma of the lung. It is also classified as a pulmonary neuroendocrine tumor.
The incidence peaks around the sixth decade 6. There is an increased male predilection 7.
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 tumor and account for ~8% of malignant soft tissue tumors 10.
Lepidic-predominant adenocarcinoma (LPA) of the lung, formerly known as non-mucinous bronchoalveolar carcinoma, is a subtype of invasive adenocarcinoma of the lung characterized histologically when the lepidic component comprises the majority of the lesion.
The category of 'lepid p...
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...
Leptomeningeal metastases, also know as carcinomatous meningitis, refers to the spread of malignant cells through the CSF space. These cells can originate from primary CNS tumors (e.g. drop metastases), as well as from distant tumors that have metastasised via haematogenous spread.
Leukemia CNS manifestations can be divided into those related to the disease itself and those associated with its treatment. Leukaemias are haematologic malignancies in which occur a proliferation of hematopoietic cells at an undifferentiated or partially differentiated stage of maturation 1.
Lhermitte-Duclos disease, also known as dysplastic cerebellar gangliocytoma, is a rare tumor of the cerebellum. It is probably hamartomatous, although the exact pathogenesis remains unknown 2,6. Even though it may not be neoplastic, it is considered a WHO grade I tumor in the current WHO classif...
Liposclerosing myxofibrous tumors (LSMFT), also known as polymorphic fibro-osseous lesions of bone, are rare benign fibro-osseous lesions that have a predilection for the intertrochanteric region of the femur.
It is slightly more common in males with mean age of 30-40 yea...
LI-RADS (Liver Imaging Reporting and Data System) is both a set of standardized terminology and a classification system for imaging findings in liver lesions. The LI-RADS score for a liver lesion is an indication of its relative risk for hepatocellular carcinoma (HCC). The classification system ...
Littoral cell angioma of the spleen (LCA) is a rare and relatively recently (1991) described vascular tumor of the spleen.
Littoral cell angiomas may occur at any age and have no gender predilection.
Typically, patients with littoral cell angioma are found ...
Liver tumors, like tumors of any organ, can be classified as primary or secondary.
Liver metastases are by far the most common hepatic malignancy, with many of the most common primaries readily seeding to the liver. This is especially the case with gastrointestinal tract tumors, due...
Lobular breast carcinoma is a subtype of breast cancer can range from lobular carcinoma in situ (LCIS) to invasive lobular carcinoma.
Multicentricity and bilaterality tend to be quite common with lobular breast carcinomas.
Lobular carcinoma in situ (LCIS) represents the next step up from atypical lobular hyperplasia (ALH) along the malignant spectrum of lobular breast carcinoma.
LCIS occurs predominantly in premenopausal women with a mean age of 45 years old, approximately 10-15 years younger than t...
The lollipop sign is seen in hepatic epithelioid hemangioendothelioma (HEHE). It represents hepatic/portal vein and/or their tributaries/branches tapering and terminating at or just within the edge of a well defined peripherally enhancing (or non-enhancing) lesion with an avascular core on CT or...
Low-grade appendiceal mucinous neoplasms (LAMN), previously known as appendiceal mucinous cystadenomas, are rare mucinous tumors of the appendix showing low-grade cytologic atypia, c.f. high-grade appendiceal mucinous neoplasms.
Considerable controversy still exists on mucinous ne...
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...
The Lugano staging system is a lymphoma staging classification system resulting from recommend changes to the Cotswolds-modified Ann Arbor classification following meetings in 2011.
The goal was to simplify and standardize the response assessment enabling better understanding and communication ...
The Lugano classification is a lymphoma staging system resulting from recommended changes in 2011 to the Cotswolds modified Ann Arbor staging. This article outlines the lesion measurement guidelines for the system:
lymph nodes: the longest diameter in axial plane should be >1....
The Lugano classification is a lymphoma staging system resulting from recommended changes in 2011 to the Ann Arbor staging with Cotswolds modifications. This article outlines the classification's response to treatment based on CT.
Also included in the classification are staging and reponse to ...
The Lugano classification is a lymphoma staging system resulting from recommended changes in 2011 to the Cotswolds modified Ann Arbor staging. This article outlines the classification's response to treatment based on PET/CT.
Also included in the classification are staging and reponse to treatm...
Lung cancer, or frequently if somewhat incorrectly known as bronchogenic carcinoma is a broad term referring to the main histological subtypes of primary lung malignancies that are mainly linked with inhaled carcinogens, with cigarette smoke being a key culprit.
This article will broadly discu...