Articles

Articles are a collaborative effort to provide a single canonical page on all topics relevant to the practice of radiology. As such, articles are written and edited by countless contributing members over a period of time. A global group of dedicated editors oversee accuracy, consulting with expert advisers, and constantly reviewing additions.

755 results found
Article

Distal appendicular skeletal metastases

Distal appendicular skeletal metastases, especially distal to the knee and elbow joints, are uncommon. Clinical presentation Localized pain and swelling, along with pathological fractures, are the most common 3.  Pathology Etiology Malignancies that most commonly spread to appendicular skel...
Article

Drash syndrome

Drash syndrome, also known as the Denys-Drash syndrome, is associated with an abnormal WT1 gene (Wilms tumor gene) and consists of: Wilms tumor male pseudohermaphroditism progressive glomerulonephritis
Article

Ductal adenoma of the breast

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

Duodenal adenocarcinoma

Duodenal adenocarcinoma is the most common primary malignancy of the duodenum. Epidemiology Adenocarcinoma is the most common primary malignant neoplasm of the duodenum. It represents 0.3% of all gastrointestinal malignancies and accounts for  50-70% of small bowel adenocarcinomas occurring ei...
Article

Duodenal filling defects

Duodenal filling defects may be caused by a wide variety of duodenal pathology which may be divided by their location and pathological process. Extrinsic gallbladder impression common bile duct impression gas-filled diverticulum Intrinsic Note: please refer to duodenal mucosal nodular fill...
Article

Dural metastases

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

Dural tail sign (mnemonic)

A useful mnemonic to remember differential diagnoses associated with a dural tail sign is: My Scary Dog Likes To Stand Guard Mnemonic M: meningioma S: sarcoidosis D: dural metastases L: lymphoma T: tuberculoma S: schwannoma G: glioma
Article

Dysembryoplastic neuroepithelial tumor

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

Dysplastic liver nodules

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

EBV associated smooth muscle tumor

Epstein-Barr virus-associated smooth muscle tumors (EBV-SMT) are rare and encountered in immunocompromised individuals. Epidemiology These tumors are generally exceedingly rare, and only seen with any frequency in the setting of immunosuppression, particularly in HIV/AIDS patients, but also po...
Article

ECOG performance status

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

EGFR mutation

Epidermal growth factor receptor (EGFR) mutation can be expressed in a large proportion of non-small cell lung carcinomas (NSCLC). However, certain subtypes such as invasive mucinous adenocarcinoma of the lung can have very low expression. The presence of this mutation can be assessed on biopsy...
Article

Electron therapy

Electron therapy, or electron beam therapy, is a form of radiotherapy which is used to treat superficial lesions. Electron beams are rapidly attenuated by soft tissue and thus can only treat to a depth of a few centimeters (typically 0-3 cm), compared to megavoltage x-rays which are much more pe...
Article

Elevated vitamin B12

Elevated vitamin B12 (also known as hypervitaminosis B12 or hypercobalaminemia) is most important as a diagnostic and prognostic marker for malignant disease 1,3. Very high serum levels of vitamin B12, following dietary megadosing, does not seem to have any observable deleterious effects 2. 
Article

Endobronchial metastases (mnemonic)

Primary neoplasms which may result in endobronchial metastases may be memorized by utilizing the following mnemonic: Kiss My RBC 1  Mnemonic K: Kaposi sarcoma M: melanoma R: renal cell carcinoma B: breast cancer C: colorectal carcinoma, cervical carcinoma, carcinoid See also endobronchi...
Article

Endometrial carcinoma

Endometrial carcinoma is generally considered the most common gynecological malignancy 1,5. It frequently presents with vaginal bleeding. Both ultrasound and pelvic MRI are useful modalities for evaluation. Epidemiology Endometrial carcinoma is the most common gynecological malignancy, with pe...
Article

Endometrial hyperplasia

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. Epidemiology Endometrial hyperplas...
Article

Endosteal scalloping

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

Engraftment syndrome

Engraftment syndrome (ES) refers to a potential early complication of haematopoetic stem cell transplantation. It is thought to be related to increased capillary permeability and comprises of a combination of symptoms and signs which include fever erythrodermatous skin rash noncardiogenic pul...
Article

Eosinophil

Eosinophils, also less commonly known as acidophils, are myeloid granulocytes and form one of the main types of white blood cells. Their counts are routinely measured as part of a full blood count. They have important roles in fighting parasitic infections, but are increasingly recognized as hav...
Article

Ependymoma

Ependymomas represent a relatively broad group of glial tumors 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 pediatric brain tumors and up to 33% of brain tumors occurring...
Article

Esophageal and esophagogastric junction adenocarcinoma (staging)

Esophageal and esophagogastric junction adenocarcinoma staging refers to TNM staging of adenocarcinoma originating in the esophagus or esophagogastric junction (including tumors whose center is within the proximal 2 cm of the gastric cardia). Related histologies included in this system are high ...
Article

Esophageal and esophagogastric junction neuroendocrine tumor (staging)

Esophageal and esophagogastric junction neuroendocrine tumor staging refers to TNM staging of epithelial cancers other than the squamous cell carcinoma and adenocarcinoma groups located in the esophagus or esophagogastric junction (including tumors whose center is within the proximal 2 cm of the...
Article

Esophageal and esophagogastric junction squamous cell carcinoma (staging)

Esophageal and esophagogastric junction squamous cell carcinoma staging refers to TNM staging of squamous cell carcinoma originating in the esophagus or esophagogastric junction (including tumors whose center is within the proximal 2 cm of the gastric cardia). Related histologies included in thi...
Article

Ewing sarcoma

Ewing sarcomas are the second most common malignant primary bone tumors of childhood after osteosarcoma, typically arising from medullary cavity with invasion of the Haversian system. They usually present as moth-eaten destructive permeative lucent lesions in the shaft of long bones with large s...
Article

Ewing sarcoma family of tumors

The Ewing sarcoma family of tumors are a group of small round blue cell tumors that are closely histogenetically related, all demonstrating non-random t(11;22)(q24;q12) chromosome rearrangement resulting in the formation of the EWS-ETS fusion gene 1-3.  Terminology Although the literature is l...
Article

Exophytic

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...
Article

External beam radiotherapy

External beam radiotherapy (EBRT) (also known as teletherapy) is a form of ionizing radiation therapy delivered by a medical linear accelerator (or historically a cobalt-60 source) to a patient lying on a treatment bed. Megavoltage x-rays (4-25 MV) are the most commonly used. Alternative forms o...
Article

Extra-adrenal myelolipoma

Extra-adrenal myelolipomas occur outside the adrenal glands, with the most common sites being the retroperitoneum, thorax, and pelvis.  Epidemiology The widespread application of modern imaging techniques has led to increase in the detection of extra-adrenal myelolipomas. The exact incidence i...
Article

Extramammary Paget disease

Extramammary Paget disease (EMPD) is the rarer non-breast form of Paget disease of the nipple. It is considered a form of adenocarcinoma of the apocrine glandular tissue. In men the penis and scrotum are most frequently involved, and in women the vulva. Nodal and distant organ metastatic disease...
Article

Extramedullary hematopoiesis

Extramedullary hematopoiesis 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 hematopoiesis in the...
Article

Extramedullary hematopoiesis in the spleen

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

Extranodal extension

Extranodal extension refers to the growth of a nodal cancer metastasis beyond the confines of the capsule of a lymph node into adjacent tissues. Less preferred synonyms include extranodal spread, extracapsular extension, or extracapsular spread. This finding holds prognostic implications. For e...
Article

Extraprostatic extension of prostate cancer

Extraprostatic (extracapsular) extension of prostate cancer refers to local tumor growth beyond the fibromuscular band surrounding the prostate gland. It is a pathological finding important to prostate cancer staging. Radiographic features Though imperfect, MRI is superior to transrectal ultra...
Article

F-18 fluorodeoxyglucose

F-18 fluorodeoxyglucose (FDG) is the most common PET radiotracer. Structure The radiopharmaceutical consists of the fluorine-18 radionuclide substituting the hydroxyl group at the C-2 position of glucose. The IUPAC chemical name is 2-deoxy-2-[F-18]fluoroglucose. Production F-18 fluoride ion ...
Article

Facial nerve schwannoma

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

Familial adenomatous polyposis syndrome

Familial adenomatous polyposis syndrome (FAPS) is characterized by the presence of hundreds of adenomatous polyps in the colon. It is the most common of the polyposis syndromes. Terminology Familial polyposis coli, attenuated familial adenomatous polyposis and Gardner syndrome are all variants...
Article

Familial atypical multiple mole melanoma syndrome

Familial atypical multiple mole melanoma (FAMMM) syndrome is an autosomal dominant genodermatosis characterized by multiple melanocytic nevi (often more than 50) and a family history of melanoma. Pathology Genetics It is associated with mutations in the CDKN2A gene and shows reduced penetranc...
Article

Fascicular sign

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

Fetal adenocarcinoma of the lung

Fetal adenocarcinoma of the lung (FLAC) is a rare form of adenocarcinoma of lung (falls under invasive category). Epidemiology Some reports suggest its occurence at ~0.1%-0.5% of all pulmonary neoplasms 1.  Despite its "fetal" tissue morphology it typically presents in middle aged to elderly p...
Article

Fetal cardiac tumors

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

Fibrinous pericarditis

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

Fibrolamellar hepatocellular carcinoma

Fibrolamellar hepatocellular carcinoma is a distinct histological variant of hepatocellular carcinoma characterized on microscopy by laminated fibrous layers between the tumor cells. It is important as it has different demographics and risk factors compared to 'standard' hepatocellular carcinoma...
Article

Fibrosarcoma

Fibrosarcomas are malignant tumors of fibroblast origin. They are a type of soft tissue sarcoma that can be grouped by the patient age, i.e. adult fibrosarcoma and infantile fibrosarcoma, and/or anatomical region, for example: fibrosarcoma of the breast fibrosarcoma of the chest wall fibrosar...
Article

Fibrosarcoma of the breast

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

FIGO staging system

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

Finger clubbing

Finger clubbing, also called "drumstick fingers", is a common clinical sign in patients with heart or lung disease. The term is used to describe an enlargement of the distal phalanges of the fingers, giving them a drumstick or club-like appearance.  Clinical Presentation Finger clubbing presen...
Article

Flare phenomenon (bone scintigraphy)

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

Fluid-fluid levels in bone tumors

Fluid-fluid levels in bone tumors is a commonly encountered finding, both in benign as well as malignant bone tumors, and can be used to differentiate between the two. Method of assessment On the sagittal T2W image: measure the length of the largest fluid-fluid level (A) measure the maximum ...
Article

Fluorine-18-labeled sodium fluoride

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

Focal gas collection in right upper quadrant (differential)

Focal gas collection in right upper quadrant on plain radiographs can occur from a number of pathologies. Things to consider are: enterobiliary fistula: common types include cholecystoduodenal fistula and cholecystocolic fistula. It may occur with: gallstone ileus (being most common) 3 perfor...
Article

Focal sclerotic bony lesions (mnemonic)

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

Follicular lymphoma

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

Follicular thyroid cancer

Follicular thyroid carcinoma (FTC) is the second most frequent malignancy of the thyroid gland after papillary cancer and accounts for ≈10-20% of all thyroid neoplasms.  Epidemiology It typically occurs in women and in an older age group than papillary (i.e. 40-60 years of age). Pathology Un...
Article

Fukuoka consensus guidelines

Fukuoka consensus guidelines, also referred to as the Tanaka criteria, is a classification system for intraductal papillary mucinous neoplasms (IPMNs) and mucinous cystic neoplasms (MCNs).  The prior international consensus guidelines (2006) were referred to as the Sendai criteria, which later ...
Article

Gallbladder carcinoma

Gallbladder carcinoma is a term referring to primary epithelial malignancies arising from the gallbladder, in which the great majority (90%) are adenocarcinomas and the remainder are squamous cell carcinomas. They are more prevalent in elderly women and, in most cases, are only symptomatic when ...
Article

Gallbladder malignancy

Gallbladder malignancy (or gallbladder cancer) is relatively uncommon. The commonest histopathological type is carcinoma. Primary gallbladder carcinoma gallbladder adenocarcinoma: most common 1 gallbladder squamous cell carcinoma gallbladder neuroendocrine carcinoma gallbladder sarcoma: ve...
Article

Gallbladder metastases

Gallbladder metastases are rare and usually represent an advanced and end-stage of malignancy. Malignant melanoma and gastric carcinoma account for the most common primary malignancies to see metastases to the gallbladder, in the Western and Asian societies, respectively.  Epidemiology They re...
Article

Gallium-68 DOTATATE

Gallium-68 DOTATATE​​ (or Ga-68 DOTATATE) is a PET radiotracer that is useful for evaluating primary and metastatic well-differentiated neuroendocrine tumors. It is a form of somatostatin-receptor (SSTR) functional imaging and most often combined with cross-sectional imaging in the form of PET-C...
Article

Gamma Knife

Gamma Knife®, also known as Gamma Knife radiosurgery (GKRS), is a form of radiosurgery historically employing 201 cobalt-60 sources arranged in a hemispheric array. The latest system, the Gamma Knife Perfexion™, uses 192 cobalt-60 sources 1. The emitted gamma rays are focused on a target point w...
Article

Ganglioglioma

Gangliogliomas are uncommon, usually low-grade, CNS tumors. Epilepsy is a common clinical presentation and this tumor has a typical occurrence in the temporal lobes, although they have been described in all parts of the central nervous system. Their appearance on imaging is very variable: from ...
Article

Gastric adenocarcinoma

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

Gastric cancer (summary)

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

Gastric lymphoma

Gastric lymphoma may either represent secondary involvement by systemic disease or primary malignancy confined to the stomach.  Epidemiology  Gastric lymphoma represents the most common site of extranodal lymphoma, accounting for 25% of all such lymphomas, 50% of all gastrointestinal lymphomas...
Article

Gastric metastases

Gastric metastases are rare, found in less than 2% of patients who die of a carcinoma 6. Epidemiology Usually affects the middle-aged and elderly population. Affects males and females equally without predilection. Clinical presentation The patient may be asymptomatic, but the most common sig...
Article

Gastrointestinal stromal tumor

Gastrointestinal stromal tumors (GIST) are the most common mesenchymal tumors of the gastrointestinal tract. They account for ~5% of all sarcomas, and are mostly found within stomach and mid-distal small bowel. They respond remarkably well to chemotherapy. Terminology Previously these tumors h...
Article

Generalized osteopenia

Generalized osteopenia refers to osteopenia diffusely affecting the bones. Differential diagnosis The differential diagnosis is wide and includes: osteoporosis: decreased osteoid production osteomalacia: undermineralisation of osteoid hyperparathyroidism multiple myeloma diffuse metastase...
Article

Germ cell tumors (mnemonic)

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

Gestational trophoblastic disease

Gestational trophoblastic disease (GTD) results from the abnormal proliferation of trophoblastic tissue and encompasses a wide spectrum of diseases, including: hydatidiform mole complete mole partial mole coexistent molar pregnancy invasive mole ~10% choriocarcinoma (gestational choriocarc...
Article

Giant breast masses

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

Giant cell tumor of bone

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. Epidemiology Giant cell tumo...
Article

Gliosarcoma

Gliosarcomas are a variant of glioblastoma (along with epithelioid glioblastoma and giant cell glioblastoma) recognized in the current (2016) WHO classification of CNS tumors 9. They are highly malignant (WHO grade IV) primary intra-axial neoplasms with both glial and mesenchymal elements. Term...
Article

Gynecologic imaging reporting and data system (GI-RADS)

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. Classification Findings are classified into five categories 1: GI-RADS 1 normal ovaries identified and no adn...
Article

Hemangioblastoma (central nervous system)

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 ...
Article

Hematopoietic stem cell transplantation

Hematopoietic stem cell transplantation (HSCT) (encompasses bone marrow transplantation (BMT)) is a relatively common procedure used to treat a wide spectrum of conditions 1,2: lymphoproliferative disorders, e.g. multiple myeloma (most common indication), lymphoma,  leukemia solid tumors, e.g...
Article

Hemophagocytic lymphohistiocytosis

Hemophagocytic 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. Epidemiology It typically affects infants and young c...
Article

Hemorrhage exclusion sign (prostate)

The hemorrhage exclusion sign can be a useful MRI finding following prostate biopsy. Pathology The normal prostate produces high concentrations of citrate, which among other properties, acts as an anticoagulant 1. As tumor cells are dysfunctional, they will produce lower levels of citrate than...
Article

Hemorrhagic intracranial metastases (mnemonic)

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

Halo sign (osseous)

The Halo sign in bone imaging refers to the presence of a hyperintense rim around an osseous lesion on T2-weighted MRI, which is an indicator of a metastatic lesion 1.
Article

Hamartoma

A hamartoma is a benign tumor-like malformation that consists of a collection of architecturally disorganized cells located in an area of the body where the cells are normally found. It is often due to abnormal development. In radiology, hamartomas often mimic malignancy. Several hamartomata ha...
Article

Hand-foot syndrome (chemotherapy)

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.  Causative drugs Many chemotherapeutic...
Article

Hartmann procedure

Hartmann procedure (HP) (or proctosigmoidectomy) is an operation in which the sigmoid colon is resected and the distal colon brought out as a colostomy in the left iliac fossa. The remnant rectum stump is sewn shut. It is a quick and straightforward intervention and currently finds most favor in...
Article

Head and neck cancer therapy response interpretation (Hopkins criteria)

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

Head and neck squamous cell carcinoma (overview)

Head and neck squamous cell carcinomas (SCC) are common, being the sixth most common cancer. They can have a cutaneous or mucosal origin. As such there is a wide array of clinical and radiographic manifestations, and are separated into: squamous cell carcinoma of the skin of the head and neck ...
Article

Head and neck squamous cell carcinomas

Head and neck squamous cell carcinomas (HNSCC) are the most common histologic type of head and neck cancer. While the term may include any squamous cell carcinoma of the head and neck, common usage focuses on those of mucosal origin, i.e., squamous cell carcinoma of the upper aerodigestive tract...
Article

Heavy charged particle therapy

Heavy charged particle therapy (also known as heavy ion radiotherapy) is a type of particle therapy that uses ionized atoms (e.g. neon, argon, silicon, carbon etc.). Currently carbon ions are most commonly employed, termed carbon ion radiotherapy (CIRT). It is a technically-demanding technique ...
Article

Hepatic carcinosarcoma

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

Hepatic epithelioid hemangioendothelioma

Hepatic epithelioid hemangioendothelioma (HEHE) is a rare, low to intermediate grade malignant hepatic vascular tumor. Epidemiology 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. Pathology Histologi...
Article

Hepatic metastases

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.  Epidemiology The demographics of patients with l...
Article

Hepatoblastoma (staging)

As expected there are a number of different staging systems for hepatoblastoma. Staging 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 ...
Article

Hepatomegaly

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

Hepatosplenomegaly

Hepatosplenomegaly is simply the simultaneous presence of a pathologically-enlarged liver (hepatomegaly) and spleen (splenomegaly). Pathology Etiology Infection Many, many infections can produce a mild concurrent enlargement of the liver and spleen. This list is by no means exhaustive! vira...
Article

HER-2 mutations in lung cancer

Human epidermal growth factor receptor 2 (HER-2) mutations may be detected in approximately 3% of lung adenocarcinomas 1. Radiographic features CT Early studies have suggested HER2-mutant tumors exhibit more aggressive features in general and tend to: exhibit a locally-invasive behavior comp...

Updating… Please wait.

 Unable to process the form. Check for errors and try again.

 Thank you for updating your details.