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.

479 results found
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Hypopharyngeal squamous cell carcinoma (staging)

Staging of hypopharyngeal squamous cell carcinoma is performed using the TNM staging system. TNM staging Primary tumour staging (T) T1: limited to 1 subsite AND tumour size ≤ 2 cm in greatest dimension T2: extends into adjacent subsite or area (larynx, oropharynx) and/or tumour size betw...
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Hypothalamic lesions

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...
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Immature ovarian teratoma

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. Epidemiology They are considerably less common than mature ovar...
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Incidentaloma

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...
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Inferior vena caval thrombosis

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. Clinical features Patient can present with many features which include bilateral pedal oede...
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Inflammatory carcinoma of the breast

Inflammatory carcinomas of the breast also referred as inflammatory breast cancers, are a relatively uncommon but aggressive form of invasive breast carcinoma with a characteristic clinical presentation and unique radiographic appearances.  Epidemiology   Inflammatory carcinomas account for 1-...
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Intensity modulated radiation therapy (IMRT)

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...
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Intraductal papillary mucinous neoplasm

Intraductal papillary mucinous neoplasms or tumours (IPMNs or IMPTs) are cystic tumours of the pancreas. Epidemiology 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...
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Intradural extramedullary metastases

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. Epidemiology The age at presentation depends on tumour type...
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Intramedullary spinal metastasis

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 haematogenous dissemination direct extension from leptomeninges Epidemi...
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Intraosseous meningioma

Intraosseous meningioma, also referred to 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. Terminology It is important to note that it has been argued by so...
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Intraventricular masses (an approach)

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...
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Intraventricular meningioma

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. Epidemiolog...
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Intraventricular neoplasms and lesions

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 tumour types arise from, or can bulge into the ventricular system, although there are certain lesions that are relatively ...
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Invasive ductal carcinoma

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.  Epidemiology  Peak age of presentation is about 50 to 60 years. Clinical present...
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Invasive lobular carcinoma of the breast

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). Epidemiology They represent 5-10% of all breast cancer. The mean age at presentation may be higher than...
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Inverted papilloma

Inverted papillomas are a type of Schneiderian papilloma. They are uncommon with distinctive pathological and imaging features. Terminology  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...
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Investigation of haemoptysis (summary)

This is a basic article for medical students and other non-radiologists. Haemoptysis 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...
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Ischaemic colitis

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. Epidemiology Ischaemic bowel is typically a dis...
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Ishikawa classification of venous involvement by pancreatic ductal adenocarcinoma

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...
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Ivory vertebra sign

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. Pathology Aetiology The cause for an ivory vertebra depends on the age o...
Article

Juxtaglomerular cell tumour

Juxtaglomerular cell tumour (JGCT) is an infrequent renal tumour of the juxtaglomerular cells. These cells secrete renin and often cause severe hypertension and hypokalaemia. Epidemiology Juxtaglomerular cell tumour affects all age groups, but is most common in adolescents and young adults, wi...
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Kimura disease

Kimura disease is a rare benign inflammatory disease that characteristically manifests as enlargement of cervical lymph nodes and salivary glands. Epidemiology 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...
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Krenning score of neuroendocrine tumour uptake

The Krenning score is a proposed semi-quantitative method of assessing the degree of tracer uptake on octreotide scintigraphy. Parameters Initially designed for assessment of 111In-DTPA on planar imaging, the Krenning score is applicable to SPECT or SPECT/CT using various radiopharmaceuticals....
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Lambert-Eaton myasthenia syndrome

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 ...
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Langerhans cell histiocytosis (skeletal manifestations)

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...
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Large cell carcinoma of the lung

Large cell carcinoma of the lung is one of the histological types of non-small cell carcinomas of the lung. Epidemiology It is thought to account for approximately 10% of bronchogenic carcinoma 1. Clinical presentation Patients present with dyspnea, chronic cough and haemoptysis. Pathology ...
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Large cell neuroendocrine carcinoma of the lung

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 tumour. Epidemiology The incidence peaks around the sixth decade 6. There is an increased male predilection 7. Pathology ...
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Laryngeal squamous cell carcinoma (staging)

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...
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Leiomyosarcoma

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. Pathology Location  Leiomyo...
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Leptomeningeal enhancement

Leptomeningeal enhancement refers to a diffuse or focal gyriform or serpentine enhancement that can be seen in the following conditions: Diffuse meningitis pyogenic meningitis viral meningitis tuberculous meningitis (can also be focal) CNS cryptococcal infection coccidioidal meningitis (c...
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Leukaemia (CNS manifestations)

Leukaemia 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 haematopoietic cells at an undifferentiated or partially differentiated stage of maturation 1. ...
Article

Liposclerosing myxofibrous tumour

Liposclerosing myxofibrous tumours (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. Clinical presentation It is slightly more common in males with mean age of 30-40 ye...
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Littoral cell angioma of the spleen

Littoral cell angioma of the spleen (LCA) is a rare and relatively recently (1991) described vascular tumour of the spleen. Epidemiology Littoral cell angiomas may occur at any age and have no gender predilection. Clinical presentation Typically, patients with littoral cell angioma are found...
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Lobular breast carcinoma

Lobular breast carcinoma is a subtype of breast cancer can range from lobular carcinoma in situ (LCIS) to invasive lobular carcinoma. Pathology Multicentricity and bilaterality tend to be quite common with lobular breast carcinomas.
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Lobular carcinoma in situ

Lobular carcinoma in situ (LCIS) represents the next step up from atypical lobular hyperplasia (ALH) along the malignant spectrum of lobular breast carcinoma. Epidemiology LCIS occurs predominantly in premenopausal women with a mean age of 45 years old, approximately 10-15 years younger than t...
Article

Low-grade appendiceal mucinous neoplasm

Low-grade appendiceal mucinous neoplasms (LAMN), previously known as appendiceal mucinous cystadenomas, are rare mucinous tumours of the appendix showing low-grade cytologic atypia, c.f. high-grade appendiceal mucinous neoplasms. Terminology  Considerable controversy still exists on mucinous n...
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Lucent/lytic bone lesion, differential diagnosis (mnemonic)

Mnemonics for the differential diagnosis of lucent/lytic bone lesions include: FEGNOMASHIC FOG MACHINES 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...
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Lugano classification: response evaluation criteria for CT and PET/CT

The Lugano classification recommends two methods of visualization for standing lymphoma: Computer tomography (CT) Positron emission tomography–computed tomography (PET/CT) Response Assessment on CT   CT uses for the standing of all types of lymphoma (if CT is performed for tumor size measure...
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Lung cancer

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, smoking cigarettes in particular.  This article will broadly discuss al...
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Lung carcinomas of the salivary gland type

Lung carcinomas of the salivary gland type are also known as salivary gland–type tumours of the lung (SGTTLs) or bronchial gland neoplasms.  The usual consignation to the group of non-small cell lung cancer (NSCLC) may be unfortunate because the clinical behavior of SGTTLs can be quite differen...
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Lymphangitic carcinomatosis

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. Epidemiology The demographics will reflect that of the underlying malignancy (see below). Clinical presentat...
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Lymphoma

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. Epidemiology Lymphoma accounts for ~4% of all cancers 4. T...
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Lymphoma of the spinal cord

Lymphoma of the spinal cord is an uncommon manifestation of lymphoma. Although lymphoma more commonly involves the vertebral body (vertebral body tumours) or epidural compartment, intramedullary lymphoma may rarely occur.   Apparent intramedullary spinal cord lymphoma may often, in fact, repres...
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Lymphoma of the uterine cervix

Lymphoma of the uterine cervix is generally uncommon and when it does occur tends to present as cervical involvement with added background multi-organ disease rather than isolated primary cervical lymphoma 1. It is often considered part of the spectrum of uterine lymphoma. Epidemiology In the ...
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Lymphoma (staging)

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...
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Lymphomatoid granulomatosis (CNS manifestations)

Lymphomatoid granulomatosis of the central nervous system is uncommon, but represents the second most common site of involvement in patients with systemic lymphomatoid granulomatosis, after the lungs, which are most commonly involved. It is considered one of the immunodeficiency-associated CNS l...
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Male breast cancer

Male breast cancer is exceptionally rare and only accounts for less than 0.25% of male malignancies and ~0.5-1% of all breast cancer (both genders). The diagnosis is sometimes delayed due to the patient's hesitancy to seek advice. Workup from a radiological point of view is the same as for women...
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Male breast disease

Male breast disease includes a wide spectrum of conditions. Many conditions and entities that affect the female breast may also affect the male breast.  Pathology Malignant male breast cancer lymphoma dermatofibrosarcoma Benign gynaecomastia pseudogynaecomastia: fat deposition within the...
Article

Malignant biliary tract obstruction (summary)

This is a basic article for medical students and other non-radiologists 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. Reference art...
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Malignant fibrous histiocytoma

Malignant fibrous histiocytoma (MFH), which has more recently been classified as pleomorphic undifferentiated sarcoma (PUS) and formerly known as fibrosarcoma, is considered the most common type of soft tissue sarcoma. It has an aggressive biological behaviour and a poor prognosis. As in the ma...
Article

Malignant melanoma

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...
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Malignant pleural disease

Malignant pleural disease usually heralds a poor prognosis, whether it represents a primary pleural malignancy or metastatic involvement.  Clinical presentation Clinical presentation is variable. Patients may be asymptomatic or have pleuritic pain. If associated with a sizeable pleural effusio...
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Malignant pleural mesothelioma (staging)

A number of staging systems have been described for staging of malignant pleural mesothelioma. Below is the International Mesothelioma Interest Group TNM staging system. TNM T - Tumour Tx: primary tumour cannot be assessed T0: no evidence of primary tumour T1a potentially resectable only ...
Article

MALT lymphoma

Mucosa-associated lymphoid tissue (MALT) lymphoma, also called extranodal marginal zone B-cell lymphoma, is a type of low-grade extranodal lymphoma.  Epidemiology MALT lymphoma represents ~7.5% of non-Hodgkin lymphomas. The average age of presentation is 60 years with a slight female predomina...
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Mandibular lesions

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...
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Mantle cell lymphoma

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. Epidemiology They occur in older adults (mean age ~60 years). There is...
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Masaoka staging system of thymoma

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...
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Maxillary antral carcinoma

Maxillary antral carcinomas are an uncommon head and neck malignancy. They usually present late despite growing large since they remain confined to the maxillary sinus and produce no symptoms. Epidemiology Most commonly affects patients over 45 and has a strong male predilection (M:F = 5:1). M...
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Mediastinal lymph node enlargement

Mediastinal lymph node enlargement can occur from a wide range of pathologies. It may occur on its own or in association with other lung pathology. Terminology Although mediastinal lymphadenopathy is used interchangeably - by some - with "mediastinal lymph node enlargement", they are not synon...
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Meningeal haemangiopericytoma

Meningeal haemangiopericytomas are rare tumours of the meninges, now considered to be aggressive versions of solitary fibrous tumours of the dura, often presenting as a large and locally aggressive dural mass, frequently extending through the skull vault. They are difficult to distinguish on ima...
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Meningeal melanocytoma

Meningeal melanocytomas are rare benign primary melanocytic tumours of the CNS that are derived from leptomeningeal melanocytes. They can occur anywhere along the neuraxis but are most commonly found in the spinal canal near the foramen magnum, as well as the posterior fossa, Meckel’s cave, or a...
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Mesothelioma

Mesothelioma, in general, is an aggressive malignant tumour of the mesothelium. The overwhelming majority arise from the pleura, pleural mesothelioma, which this article will focus on. Given the presence of the mesothelium in different parts of the body, mesothelioma can arise in various locati...
Article

Mesothelioma (summary)

This is a basic article for medical students and other non-radiologists. Pleural mesotheliomas are malignant tumours of the lining of the lungs. There is a strong association with asbestos exposure. Reference article This is a summary article; read more in our article on mesothelioma. Summar...
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Metastases to the breast

Metastases to the breast from non-mammary primary tumours are uncommon and account for 0.5-2.0% of all breast malignancies.  Clinical presentation Metastases do not tend to cause retraction of the skin or nipple. Metastatic lesions are much more likely to be multiple or bilateral than primary ...
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Metastases to the thymus

Metastases to the thymus are rare, although they are probably under reported due to lack of symptoms.  Pathology Varied primary tumours have been reported to metastasise to the thymus 1,2: breast cancer lung cancer ovarian cancer colorectal carcinoma gastric cancer prostate cancer testi...
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Metastases to the thyroid

Metastases to the thyroid are an uncommon cause of thyroid malignancy.  Epidemiology Metastases to the thyroid represent 1.4-3% of all malignancies 5. In autopsy series, the incidence is ~10% (range 2-24%) 1,5.  Pathology The most common sites of primary malignancy include (note these will v...
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Metastases to the vagina

Metastases to the vagina are more common than primary vaginal malignancies and account for >80% of vaginal tumours. Pathology Metastases usually spread from contiguous sites most commonly, with lymphatic and hematogenous metastases also recognised. Tumors that metastasise to the vagina includ...
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Minor salivary gland tumours

Minor salivary gland tumours are a subtype of salivary gland tumours originating from the minor salivary glands, which are found in the lips, tongue, hard palate, and the mucosa of the oropharynx and larynx, among other locations. Epidemiology MSGTs account for ~15% of all salivary gland tumou...
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MRI protocols

MRI protocols are a combination of various MRI sequences, designed to optimally assess a particular region of the body and/or pathological process. There are some general principles of protocol design for each area. However, the specifics of a protocol are dependent on MRI hardware and software...
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MRI reporting guidelines for cervical cancer

MRI reporting guidelines for cervical cancer help maintain uniformity of reports and assessment of important imaging staging criteria. Tumour size The tumour should be measured in three orthogonal planes. Tumours with a maximum diameter >4 cm are usually not amenable to primary radical surgery...
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Multilocular cystic renal tumour

Multilocular cystic renal tumours (MCRT) are rare benign renal neoplasms occurring in a bimodal age distribution, involving young children and adults in the 4th and 5th decades. For logical reasons, this article will discuss together the two ends of the spectrum of this disease, cystic partiall...
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Multiple cystic neck lesions (differential)

The differential diagnosis for multiple cystic neck lesions is different to that for a solitary cystic neck mass. Differential diagnosis Cystic neck lesions are seen in: necrotic metastatic SCC nodes: older patient, M>F papillary thyroid carcinoma metastases: usually a younger patient, F>M ...
Article

Multiple myeloma

Multiple myeloma is the most common primary malignant bone neoplasm in adults. It arises from red marrow due to monoclonal proliferation of plasma cells and manifests in a wide range of radiographic abnormalities. Multiple myeloma remains incurable. Terminology Four main patterns are recognise...
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Muscle lymphoma

Muscle lymphoma is a rare manifestation of lymphoma. Epidemiology Muscle lymphoma is rare, representing <2% of all lymphomas. The average age of presentation is 70 years 1. Clinical presentation Focal swelling and/or pain along with B-type symptoms 2. Any muscle can be involved but most comm...
Article

Musculoskeletal angiosarcoma

Musculoskeletal angiosarcomas, (along with haemangiopericytomas and haemangioendotheliomas) are tumours that arise from vascular structures. They are typically difficult to distinguish from one another on imaging alone. Angiosarcomas, are the most aggressive of the three, frequently having meta...
Article

Mycosis fungoides

Mycosis fungoides (MF), also known as cutaneous T-cell lymphoma, is a type of malignant T-cell lymphoma that primarily involves the skin.  Epidemiology In the United States, it is more common in males and African Americans. In Europe, it accounts for ~6% of all non-Hodgkin lymphomas. It is rar...
Article

Myeloproliferative disorder

Myeloproliferative disorders (MPDs) are a diverse group of conditions that are characterised by the overproduction of red cells, white cells and/or platelets in bone marrow. There are numerous conditions considered in this group but the most common are:  myelofibrosis polycythaemia vera essen...
Article

Myoinositol peak

Myoinositol is one of the compounds images with MR spectroscopy (MRS) at both 1.5 T and 3 T and is seen to resonate at 3.5 ppm chemical shift (right of the choline peak).  Myoinositol is a precursor of both phosphatidylinositol (the major inositol-containing phospholipid) and of phosphatidylino...
Article

Nasopharyngeal carcinoma

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). Epidemiology Nasopharyngeal carcinoma accounts for ~70% of all primary malignancies of the na...
Article

Neonatal neuroblastoma

  Neonatal neuroblastoma is a type of congenital neuroblastoma, an embryonal tumour arising from the sympathetic nervous system. In the majority of cases (45%), the tumour is localised in the adrenal gland.  Epidemiology Neonatal neuroblastoma accounts for less than 5% of all cases and carrie...
Article

Neoplasms of the spinal canal

Neoplasms of the spinal canal encompass a range of tumours which arise from or involve the spinal cord, theca and spinal nerves. Pathology These can be divided according to the tissue/structure of origin within the spinal canal. Tumours of vertebral bodies are discussed separately: see vertebr...
Article

Nephroblastomatosis

Nephroblastomatosis refers to diffuse or multifocal involvement of the kidneys with nephrogenic rests (persistent metanephric blastema). Epidemiology Nephrogenic rest are found incidentally in 1% of infants. Pathology Nephrogenic rests are foci of metanephric blastema that persist beyond 36 ...
Article

Neuroblastoma (staging)

There are two methods of neuroblastoma staging, one that is based on post-operative patients (INSS) and one developed for pre-treatment patients (INRGSS). Staging International Neuroblastoma Staging System (INSS) This staging system is for post-operative patients and mainly for prognosis 1: ...
Article

Nonbacterial thrombotic endocarditis

Nonbacterial thrombotic endocarditis (NBTE), also referred as marantic endocarditis, refers to fibrin and platelets aggregations on previously undamaged heart valves, in patients without bacteraemia. The condition is seen in patients with advanced stage malignancies and is related to episodes of...
Article

Ocular pathology

Ocular pathology covers a wide range of conditions and therefore represents the cause of a wide range of symptoms, signs and radiographic features. Ocular metastases account for over 80% of all ocular pathology. With regard to the remainder of ocular lesions, the primary differentiating factor ...
Article

Oesophageal cancer (staging)

Oesophageal cancer staging can depend slightly on whether the tumour is squamous cell or adenocarcinoma subtype. Due to the lack of a serosal layer, oesophageal cancer often tends to have mediastinal spread at the time of diagnosis. Staging TNM staging T staging Tx: primary tumour cannot be...
Article

Oesophageal cancer (summary)

This is a basic article for medical students and other non-radiologists Oesophageal cancer is a relatively uncommon tumour that occurs within the oesophagus of affected individuals. Patients present with symptoms of increasing dysphagia that progress from solid foods to liquids. Reference arti...
Article

Oesophageal carcinoma

Oesophageal carcinoma is relatively uncommon. It tends to present with increasing dysphagia, initially to solids and progressing to liquids as the tumour increases in size, obstructing the lumen of the oesophagus. Epidemiology Oesophageal cancer is responsible for <1% of all cancers and 4-10% ...
Article

Oesophageal mass (mnemonic)

A mnemonic to remember the causes of an oesophageal mass is: CALL the MVP Mnemonic C: carcinoma A: adenoma L: lymphoma L: leiomyoma M: metastasis V: varices P: papilloma/polyp
Article

Oligometastases

Oligometastases refers to distant disease that is limited in number and distribution, Niibe et al. defined this as ≤5 metastatic/recurrent lesions with control of the primary lesion 1,2. These metastases can be treated with local measures (surgery, radiation therapy, etc.) with the aim of increa...
Article

Omental cake

Omental cake refers to infiltration of the omental fat by material of soft-tissue density. The appearances refer to the contiguous omental mass simulating the top of a cake. Masses on the peritoneal surfaces and malignant ascites may also be present.  Pathology The most common cause is metasta...
Article

Ommaya reservoir

Ommaya reservoir, also known as Ommaya shunt, is a device consisting of an intraventricular catheter connected to a reservoir (port) implanted beneath the scalp. It is used for intrathecal administration of medication such as chemotherapy (mainly in the treatment of meningeal lymphomas, but also...

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