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.

572 results found
Article

Peritoneal calcification

Peritoneal calcification is seen in a limited number of conditions that result in calcification of peritoneal structures. Therefore, the differential diagnosis is small: psammoma bodies in malignancy (most frequently cystadenocarcinoma of the ovary): fine sand-like calcification pseudomyxoma p...
Article

Peritoneal mesothelioma

Peritoneal mesothelioma is an uncommon primary tumour of the peritoneal lining. It shares epidemiological and pathological features with but is less common than its pleural counterpart, which is described in detail in the general article on mesothelioma. Other subtypes (also discussed separately...
Article

Peritoneal metastases

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. Terminology If peritoneal metastases are of an epithelial origin (as most are) and...
Article

Permeative process in bone (mnemonic)

A mnemonic for permeative processes in bone is: FIRE MD Mnemonic F: fibrosarcoma I: infection R: round cell tumours (Ewing sarcoma) E: eosinophilic granuloma M: metastases/myeloma/malignant fibrous histiocytoma D: desmoid tumour See also permeative process in bone pseudo-permeative pr...
Article

PET-CT indications

PET-CT is a combination of cross-sectional anatomic information provided by CT and the metabolic information provided by positron emission tomography (PET). PET is most commonly performed with 2-[F-18]fluoro-2-deoxy-D-glucose (FDG). Fluorine-18 (F-18) is an unstable radioisotope and has a half-...
Article

Phaeochromocytoma

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 ~10% ...
Article

Pharyngeal mucosal space

The pharyngeal (or superficial) mucosal space is one of the seven deep compartments of the head and neck. It consists of the mucosa and structures deep to the mucosa of the nasopharynx, the oropharynx, and the laryngopharynx. Gross anatomy The pharyngeal mucosal space is the most internal comp...
Article

Pilomyxoid astrocytoma

Pilomyxoid astrocytomas are an uncommon and aggressive variant of pilocytic astrocytoma with unique clinical and histopathologic characteristics. Epidemiology Pilomyxoid astrocytomas are usually encountered in young children and infants (mean age of 10-18 months), however, adults cases have be...
Article

Pineal cyst

Pineal cysts are common, usually asymptomatic, and typically found incidentally. Their importance is mainly in the fact that they cannot be distinguished from cystic tumours, especially when large or when atypical features are present. As such, many patients undergo prolonged follow-up for these...
Article

Pineal germinoma

Pineal germinomas are the most common tumour of the pineal region accounting for ~50% of all tumours, and the majority (~80%) of intracranial germ cell tumours.  Epidemiology There is a marked male predominance with a M:F of ~13:1. Most patients are 20 years or younger at the time of diagnosis...
Article

Pineal gland metastasis

Pineal gland metastasis is a rare site of metastatic disease. They usually occur concomitantly with leptomeningeal metastases. This article will discuss metastatic lesions affecting only the pineal gland. For other intracranial metastatic locations, please refer to the main article on intracran...
Article

Pineal parenchymal tumour with intermediate differentiation

Pineal parenchymal tumours with intermediate differentiation (PPTID) are, as the name suggests, tumours which fall between pineocytoma (well differentiated, WHO grade I) and pineoblastomas (poorly differentiated, WHO grade IV). They are considered WHO grade II or III tumours 2. Although these tu...
Article

Pituitary carcinoma

Pituitary carcinomas are rare tumours indistinguishable from pituitary adenomas on imaging and defined only by the presence of central nervous system or systemic metastases. Epidemiology The incidence is estimated at less than 0.5% of the pituitary symptomatic tumours 1.  Clinical presentatio...
Article

Pituitary lymphoma

Pituitary lymphoma is very rare, although lymphomatous (or leukaemic) infiltration of the perisellar dura is not infrequently encountered as part of more widespread CNS disease. This article concerns itself with involvement of the pituitary itself rather than the region more broadly. For a gener...
Article

Pituitary metastasis

Pituitary metastases are rare, and unless a systemic metastatic disease is already apparent, are often preoperatively misdiagnosed as pituitary adenomas.  This article will discuss metastatic lesions affecting only the pituitary gland. For other intracranial metastatic locations, please refer t...
Article

Pituitary microadenoma

Pituitary microadenomas are a minority of all pituitary adenomas, but can pose imaging and management challenges on account of their size and protean clinical presentations.  By definition, a microadenoma is less than 10 mm in size. If the same tumour is greater than 10 mm in size, it is then c...
Article

Pituitary stalk abnormal enhancement (differential)

Abnormal nodular enhancement of the pituitary stalk can be seen in a number of entities. Differential diagnosis tumours germinoma craniopharyngioma hypothalamic glioma pituitary lymphoma pituicytoma granular cell tumour of the pituitary (pituitary choristoma) pilocytic astrocytoma of t...
Article

Pleomorphic adenoma of the salivary glands

Pleomorphic adenomas, also known as benign mixed tumours (BMTs), are the most common salivary gland tumours. On imaging, they commonly present as well circumscribed rounded masses, most commonly located within the parotid gland, hypoechogenic on ultrasound and bright on T2WI with homogeneous en...
Article

Pleomorphic carcinoma of lung

Pleomorphic carcinoma of the lung is a rare type of lung tumour. They are classified under sarcomatoid carcinomas of the lungs. Epidemiology These tumours are thought to account for 0.1-0.4% of all lung malignancies. Associations There is a recognised association with smoking. Pathology Hi...
Article

Pleural lymphoma

Pleural involvement with lymphoma can occur in two situations: primary pleural lymphoma primary effusion lymphoma secondary involvement of the pleura with lymphoma
Article

Pleural metastases

Pleural metastases are one of the vast majority of malignant lesions of the pleura. Clinical presentation 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...
Article

Pleuropulmonary blastoma

Pleuropulmonary blastomas (PPB) are a rare, variably aggressive, childhood primary intrathoracic malignancy. In up to 25% of cases, the mass can be extrapulmonary with attachment to the parietal pleura.  Epidemiology PPB is encountered in childhood, mostly in the first years of life (90% in th...
Article

Plexiform neurofibroma

Plexiform neurofibroma is an uncommon variant of neurofibroma, a benign tumour of peripheral nerves (WHO grade I), arising from a proliferation of all neural elements. Plexiform neurofibromas are essentially pathognomonic of neurofibromatosis type 1 (NF1). Unlike small sporadic localised neurofi...
Article

POEMS syndrome

POEMS syndrome is the acronymic name for a rare multisystem paraneoplastic disorder comprising of a minimum of three of the following features in the setting of a plasma cell dyscrasia: P: polyneuropathy O: organomegaly hepatomegaly, splenomegaly or lymphadenopathy E: endocrinopathy diabete...
Article

Pool sign (intracranial; metastatic adenocarcinoma)

The pool sign is a recently described brain MRI appearance where an intracranial mass exhibits a T2 hyperintense rim adjacent to a solid mass surrounded by peritumoral oedema. This appearance has been recently suggested to be a feature characteristic of metastatic adenocarcinoma (with various pr...
Article

Porocarcinoma

Porocarcinoma (or eccrine porocarcinoma) is a rare type of malignant eccrine sweat gland tumour, more frequently encountered in the lower extremities (feet and legs). It arises from the intraepidermal portion of eccrine sweat glands or acrosyringium. It represents 0.005-0.01% of all cutaneous t...
Article

Post surgical breast scar

Post surgical breast scar is a benign complication that usually occurs following  surgical intervention to breast tissue. It can however be a strong and potentially very confusing mimicker of breast malignancy. Radiographic features Review of the patient's past history and previous mammography...
Article

Preinvasive adenocarcinoma lesion of the lung

Preinvasive lesions for lung adenocarcinoma are a category of small non-invasive 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 ...
Article

Primary benign cardiac tumours

Primary benign cardiac tumours are much less common than secondary metastatic deposits. However they are more likely when a cardiac mass is seen outside of the setting of terminal metastatic disease. Tumours include 1-2: cardiac myxoma most common in adults accounts for ~50% of all primary be...
Article

Primary bone lymphoma

Primary bone (skeletal/osseous) lymphoma (PBL) is a less common manifestation of lymphoma than secondary involvement from disseminated lymphoma. It is rare, accounting for <5% of bone tumours and <1% of non-Hodgkin lymphoma. Terminology PBL is defined as the presence of lymphoma isolated to on...
Article

Primary breast chondrosarcoma

Primary breast chondrosarcoma is a rare type of sarcoma that originates from the mammary stroma and not from the underlying bone or cartilage of the chest wall. Epidemiology The prevalence of primary breast chondrosarcoma is reported to be 0.5-1%, they represent <5% of all sarcomas 1,14. Clin...
Article

Primary cutaneous melanoma

Primary cutaneous melanoma is the most common subtype of malignant melanoma, a malignant neoplasm that arises from melanocytes. Melanocytes predominantly occur in the basal layer of the epidermis but do occur elsewhere in the body. Primary cutaneous melanoma is by far the most common type of pri...
Article

Primary hepatic lymphoma

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...
Article

Primary intracranial leiomyosarcoma

Primary intracranial leiomyosarcomas are primary malignant tumours derived from smooth muscle cell lineage in the cranial vault. Epidemiology Primary intracranial leiomyosarcomas are extremely rare. Most commonly, these lesions have been described as EBV-associated smooth muscle tumours in pat...
Article

Primary malignancy of the nasopharynx

There are a number of primary malignancies of the nasopharynx: nasopharyngeal carcinoma (squamous cell carcinoma): 70% lymphoma (sinonasal lymphoma): 20% other adenocarcinoma adenoid cystic carcinoma carcinosarcoma extramedullary plasmacytoma fibrosarcoma melanoma rhabdomyosarcoma sin...
Article

Primary mediastinal large B-cell lymphoma

Primary mediastinal large B-cell lymphoma is a distinct entity, recognised in the WHO classification of lymphoma. Epidemiology Primary mediastinal large B-cell lymphoma accounts approximately 5% of large B-cell lymphoma, which is usually disseminated or found in the abdomen. There appears to b...
Article

Primary ovarian lymphoma

Primary ovarian lymphoma (POL) refers to involvement of the ovary with lymphoma but without the involvement of any other site. It is an extremely rare yet well-recognised condition. Epidemiology POL accounts for ~1.5% of ovarian tumours 5. Pathology The rarity of this condition is probably c...
Article

Primary pleural lymphoma

Primary pleural lymphoma is extremely rare, especially in immunocompetent patients. Epidemiology Primary pleural lymphoma accounts for <0.5% of all non-Hodgkin lymphoma 2 and ~2.5% of primary chest wall tumours 4.  Pathology Primary pleural lymphoma may be Hodgkin or non-Hodgkin lymphoma wit...
Article

Primary prostatic malignant melanoma

Primary melanoma of the prostate is rare, and usually cannot be diagnosed on imaging alone. In many cases, it is believed that in fact the tumour represents prostatic involvement by melanoma of the urethra. Epidemiology Primary malignant melanoma of the prostate represent both a tiny fraction ...
Article

Primary pulmonary lymphoma

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...
Article

Primary pulmonary synovial sarcoma

Primary pulmonary synovial sarcoma is an extremely rare tumour and refers to a situation where a synovial sarcoma arises from the lung as a primary site. It together with a pleural synovial sarcoma comes under the broader category of pleuro-pulmonary synovial sarcomas 3. Epidemiology It accoun...
Article

Primary sarcomatoid carcinoma of the lung

Primary sarcomatoid carcinomas of the lung refer to a heterogeneous group of non-small cell lung carcinomas (NSCLC). Epidemiology They are thought to account for 0.2 to 1% of all lung cancers 1. A sarcomatoid histology may be present in 0.1-0.4% of non-small cell lung cancers 3.  Pathology T...
Article

Primary urethral cancer

Primary urethral cancer, in most cases a urethral carcinoma, is a rare urological malignancy. It can be divided in female urethral cancer and male urethral cancer. Epidemiology It has an incidence of 4.3 per million for males and 1.5 per million for females. It usually manifests in the fifth d...
Article

Primary urethral cancer (staging)

Primary urethral cancer staging often uses the TNM system and is as follows: TNM staging Primary tumour staging (T) Tx: primary tumour cannot be assessed T0: no evidence of primary tumour Tis: carcinoma in situ Ta: non-invasive papillary, polypoid, or verrucous carcinoma T1: invasion of s...
Article

Primary urethral malignant melanoma

Melanoma of the urethra is a very rare tumour of the male urethra and often presents as an invasive prostatic mass. As such it is usually referred to as primary prostatic malignant melanoma.
Article

Primary uveal malignant melanoma

Malignant uveal melanomas, also referred as choroidal melanomas, are the most common primary tumour of the adult eye 3.  Epidemiology Malignant melanoma of the uvea is the most common primary intraocular malignancy and is predominantly seen in Caucasians 5. The incidence of these tumours incre...
Article

Prostate cancer (staging)

Prostate cancer staging can be thought of in terms of physical location or grading histologically. The TNM classification is used to determine spread, and the Gleason score is used to determine the histological type. Another staging system is the Jewett-Whitmore staging system. Additionally, th...
Article

Prostate Imaging Reporting and Data System

PI-RADS (Prostate Imaging Reporting and Data System) refers to a structured reporting scheme for evaluating the prostate for prostate cancer. It is designed to be used in a pre-therapy patient. The original PI-RADS score was annotated, revised and published as the second version, PI-RADS v2 6, ...
Article

Prostate specific antigen

Prostate specific antigen (PSA) is currently used as a tumour marker for prostate adenocarcinoma. PSA is a 33 kilodalton glycoprotein produced in prostate epithelial cells. Its normal physiologic role is as a liquefying agent for seminal fluid; only a tiny amount leaks into the blood, therefore...
Article

Prostate-specific membrane antigen

Prostate-specific membrane antigen (PSMA) (also known as glutamate carboxypeptidase II) is a type II transmembrane glycoprotein that has become an increasingly prominent imaging biomarker 1. PSMA has emerged as a useful target in PET imaging of prostate cancer, especially in the evaluation of sm...
Article

Prostatic carcinoma

Prostatic carcinoma ranks as the most common malignant tumour in men and the second most common cause of cancer-related deaths in men. Prostatic adenocarcinoma is by far the most common histological type and is the primary focus of this article. Epidemiology It is primarily a disease of the el...
Article

Protoplasmic astrocytoma

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...
Article

PSA density

The PSA density (PSAD), is a calculation performed at diagnosis and is the serum PSA level divided by the volume of the prostate gland.  PSA density has been used as a prognostication tool in helping decide between a watch-and-wait or an invasive approach when managing prostate carcinoma. The c...
Article

Pseudocirrhosis

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...
Article

Pseudo Meigs syndrome

Pseudo Meigs syndrome refers to a clinical syndrome of pleural effusion, ascites associated with an ovarian tumour that is not a fibroma or a fibroma-like tumour. Pathology Entities that have been reported to result in pseudo Meigs syndrome include Krukenberg tumours colon carcinoma metastas...
Article

Pseudomyxoma peritonei

Pseudomyxoma peritonei refers to the intraperitoneal accumulation of a gelatinous ascites secondary to rupture of a mucinous tumour. The most common cause is a ruptured mucinous tumour of the appendix/appendiceal mucocoele 10.   Occasionally, mucinous tumours of the colon, rectum, stomach, panc...
Article

Pulmonary artery sarcoma

Pulmonary artery sarcomas are extremely rare tumours that originate from the intimal mesenchymal cells of the pulmonary artery. It is frequently misdiagnosed as pulmonary thromboembolism.  Epidemiology  Primary malignant tumours of the pulmonary arteries are very rare with an incidence of 0.00...
Article

Pulmonary lymphoma

Pulmonary lymphoma refers to lung parenchymal involvement with lymphoma. Pathology 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...
Article

Pulmonary metastases

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. Epidemiology The epidemiology will match that of the ...
Article

Pulmonary opacification

Pulmonary opacification represents the result of a decrease in the ratio of gas to soft tissue (blood, lung parenchyma and stroma) in the lung. When reviewing an area of increased attenuation (opacification) on a chest radiograph or CT it is vital to determine where the opacification is. The pat...
Article

Pure ground glass nodules

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 ...
Article

Radial scar

Radial scar, or complex sclerosing lesion, is a rosette-like proliferative breast lesion. It is not related to surgical scarring. Some authors, however, reserve the latter term to lesions over 1 cm 5.  It is an idiopathic process with sclerosing ductal hyperplasia.  Its significance is that it...
Article

Radiation-induced carcinogenesis

Radiation-induced carcinogenesis is widely but not universally believed to occur at exposures from ionising radiation used in medical imaging. It is thought to be a stochastic effect of ionising radiation, with the linear no-threshold theory (LNT) proposing no "safe" level of radiation exposure,...
Article

Radiation-induced cerebral vasculopathy

Radiation-induced cerebral vasculopathy encompasses a complex and broad range of effects on the intra- and extracranial vessels resulting from injury from radiation exposure. Manifestations can include haemorrhages and ischaemic strokes, cavernoma and capillary telangiectasias, and large vessel ...
Article

Radiation-induced glioma

Radiation-induced gliomas are a rare complication of cranial irradiation, occurring in less than 3% of cases 15 years post treatment. Glioblastomas correspond to three-quarters of all radiation induced gliomas.  The risk of developing a secondary CNS cancer following radiation exposure has been...
Article

Radiation-induced heart disease

Radiation-induced heart disease, also known as radiation cardiotoxicity, describes an uncommon constellation of potential cardiac complications of mediastinal radiotherapy. Epidemiology The demographics of patients affected by radiation-induced heart disease are those of the underlying conditi...
Article

Radiation-induced lung cancer

Radiation-induced lung cancers have been reported as a rare late complication of radiation therapy in both post-operative breast cancer and Hodgkin lymphoma patients. These occur 5-10 years (or later) after treatment 1-4. There appears to be increased risk of lung cancer in these patients if the...
Article

Radiation-induced neuritis

Radiation-induced neuritis is a complication of radiotherapy that may present with visible changes on MRI. It is likely to be most relevant in the head and neck region. There is only scarce radiology literature on the subject; radiation-induced optic neuritis is best documented. Radiographic fe...
Article

Radiation-induced pulmonary fibrosis

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...
Article

Radiation-induced sarcoma

Radiation-induced sarcoma (RIS) can originate in either the irradiated bone or soft tissues after a period of latency. They are usually high-grade tumours with a poor prognosis when compared with primary sarcomas. Malignant fibrous histiocytoma and osteosarcoma are the two most common histologic...
Article

Radiation-induced thyroid cancer

Radiation-induced thyroid cancer is an important aetiology of thyroid cancer.  Epidemiology Information about radiation induced thyroid malignancies comes from several long-term cohort studies along with some case controlled studies and their subsequent meta-analyses. Although these studies va...
Article

Radioembolisation

Radioembolisation is the delivery of radioactive microspheres to cancers using an endovascular approach. It is often performed as an outpatient procedure.  Indications hepatocellular carcinoma hepatic metastases from colorectal carcinoma Contraindications Absolute contraindications excessi...
Article

Radiomics

Radiomics is a new emerging field in which medical images are converted into multidimensional data by data-characterisation algorithms. The data is assessed for improved decision support. Radiomics has the potential to uncover disease characteristics that fail to be recognised by the naked human...
Article

Raindrop skull

The raindrop skull appearance of calvarial multiple myeloma is the presence of multiple, well-defined lytic lesions (punched out lesions) of various size scattered throughout the skull. This term is applied as an analogy to rain hitting a surface and splashing, where it leaves a random pattern o...
Article

RANO criteria for glioblastoma

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. For ...
Article

RASopathy

RASopathies are a class of developmental disorders caused by germline mutations in genes that encode for components or regulators of the Ras/mitogen-activated protein kinase (MAPK) pathway. Epidemiology As a group, RASopathies represent one of the most common malformation syndromes, with an in...
Article

RECIST 1.1: comparison with RECIST 1.0

Response Evaluation Criteria In Solid Tumours (RECIST) was updated to version 1.1 in 2009. For both RECIST 1.0 and 1.1, the requirement for measurable disease at baseline depends on the endpoints of the clinical trial. The fundamental concept common to both versions of RECIST is that measurabl...
Article

Rectal cancer

Rectal cancer, although sharing many of the features of generic colorectal carcinoma (CRC), has some features that make it unique. These are predominantly related to its anatomical location which has implications in both preoperative imaging assessment and surgical technique. Demographics and c...
Article

Rectal cancer (staging)

Staging strongly influences the success of and rate of local recurrence following rectal cancer resection. MRI is the modality of choice for the staging of rectal cancer, to guide surgical and non-surgical management options. MRI is used at diagnosis, following downstaging chemoradiotherapy, and...
Article

Renal cell carcinoma

Renal cell carcinomas (RCC) are primary malignant adenocarcinomas derived from the renal tubular epithelium and are the most common malignant renal tumour. They usually occur in 50-70-year old patients and macroscopic haematuria occurs in 60% of the cases.  On imaging, they have a variety of ra...
Article

Renal cell carcinoma (TNM staging)

Renal cell carcinoma staging using the TNM staging system for renal cell carcinoma. Older but still widely used system in some practices is the Robson staging system. TNM staging (7th edition) T T1 T1a: tumour confined to kidney, <4 cm T1b: ltumour confined to kidney, >4 cm but <7 cm T2: l...
Article

Renal leiomyoma

Renal leiomyomas are benign tumours of the kidney originating from smooth muscle cells of the renal capsule, pelvis, calyces, or blood vessels. There is a 4-5.5% prevalence based on autopsy findings 1. Clinical presentation Renal leiomyomas are usually incidental findings. In symptomatic case...
Article

Renal lymphoma

Renal lymphoma is usually a part component of multi-systemic lymphoma - primary renal lymphoma is unusual. Typical imaging findings are multiple bilateral hypodense or infiltrative renal masses. Epidemiology While renal lymphoma has an autopsy incidence of ~45% (range 30-60%) in lymphoma pati...
Article

Renal oncocytoma

Renal oncocytomas are relatively benign renal tumours. The main clinical importance of this lesion is the difficulty in pre-operatively distinguishing it from renal cell carcinomas, as epidemiology, presentation, imaging and even histology can be very similar.  Epidemiology Renal oncocytomas a...
Article

Renal osteodystrophy

Renal osteodystrophy (ROD), also known as uraemic osteopathy, is the constellation of musculoskeletal abnormalities that occur in patients with chronic renal failure, due to concurrent and superimposed: osteomalacia (adults) / rickets (children) secondary hyperparathyroidism: abnormal calcium ...
Article

Response evaluation criteria in solid tumours

Response evaluation criteria in solid tumours or RECIST refers to a set of published rules used to assess tumour burden in order to provide an objective assessment of response to therapy. They were initially introduced in 2000 and have undergone subsequent revision in 2009 (RECIST 1.1). For the ...
Article

Retroperitoneal leiomyosarcoma

Retroperitoneal leiomyosarcoma, leiomyosarcoma arising within the retroperitoneum, is one of the commonest primary retroperitoneal neoplasms. The retroperitoneum is considered the most common extra uterine site for leiomyosarcoma.  Clinical presentation Symptoms are often non-specific with abd...
Article

Rhabdoid meningioma

Rhabdoid meningioma is a rare and aggressive subtype of meningioma, it is classified as WHO grade III. Rhabdoid morphology is associated with a poor prognosis, regardless of tumour histogenesis. It resembles other types of rhabdoid tumours with a great tendency for recurrence 1,2. Extensive necr...
Article

Rhabdomyosarcoma (genitourinary tract)

Rhabdomyosarcomas of the genitourinary tract are uncommon tumours occurring in pelvic organs.  It is a disease nearly exclusive to the paediatric population.  For a general discussion of this type of tumour, please refer to the article on rhabdomyosarcomas. Epidemiology The peak incidence of ...
Article

Rhabdomyosarcomas (biliary tract)

Rhabdomyosarcomas of the biliary tract are rare tumours, usually identified in children, with a very poor prognosis. They are usually grouped under botryoid rhabdomyosarcomas. For a general discussion of this type of tumour, please refer to the article on rhabdomyosarcomas. Epidemiology Rhabd...
Article

Rubinstein-Taybi syndrome

Rubinstein-Taybi syndrome (RTS) is a very rare genetic multi-system disorder primarily characterised by mental retardation, broad and often angulated thumbs and halluces, and distinctive facial features. Epidemiology The estimated incidence is 1 in 100,000-125,000 live births 5. Clinical pres...
Article

Salivary gland tumours

Salivary gland tumours are variable in location, origin, and malignant potential.  Pathology In general, the ratio of benign to malignant tumours is proportional to the gland size; i.e. the parotid gland tends to have benign neoplasms, the submandibular gland 50:50, and the sublingual glands a...
Article

Sarcoid-like post-immunotherapy granulomatosis

Sarcoid-like post-immunotherapy granulomatosis has been reported as an uncommon complication in patients treated with immunotherapy agents such as monoclonal antibodies. It was first reported in TNF inhibitors used to treat rheumatoid arthritis and has also been reported in various immunotherapy...

Updating… Please wait.
Loadinganimation

Alert accept

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

Alert accept Thank you for updating your details.