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.

676 results found
Article

Unilateral axillary lymphadenopathy (differential)

Unilateral axillary lymphadenopathy while being more concerning than bilateral axillary lymphadenopathy can still arise from a various benign as well as malignant causes. Benign mastitis other regional infective causes tuberculosis ipsilateral arm infection, e.g. cellulitis silicone induce...
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Unilateral testicular lesions

The differential diagnosis for unilateral testicular lesions is wide-ranging.  Neoplastic Common seminoma (40-50% of testicular malignancies) non-seminomatous germ cell tumors: testicular teratoma testicular epidermoid (teratoma with ectodermal elements only) testicular choriocarcinoma t...
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Unknown primary tumors of the head and neck (staging)

Unknown primary tumors of the head and neck staging refers to TNM staging of metastatic carcinomas in the head and neck region without an identifiable primary tumor. The typical scenario involves squamous cell carcinoma present in a cervical lymph node, no obvious primary source on clinical exam...
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Urethral diverticulum

Urethral diverticula, or urethroceles, are focal outpouchings of the urethra. They should not be confused with a ureterocele of the distal ureter. Epidemiology Urethral diverticula occur far more frequently in women than in men and are estimated to occur in 1-6% of women, especially those with...
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Vascular invasion in lung cancer

Vascular invasion in lung cancer is one of the invasive patterns that can occur in lung cancer. Dependent on the publication, this could mean: intratumoral vascular invasion (IVI)  microscopic vascular invasion (MVI) lymphovascular invasion (LVI) lymphatic permeation arterial invasion veno...
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Vertebral metastases

Vertebral metastases represent the secondary involvement of the vertebral spine by haematogenously-disseminated metastatic cells. They must be included in any differential diagnosis of a bone lesion in a patient older than 40 years. This article will focus only on the metastasis involving the b...
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Vertebra plana

Vertebra plana (pleural: vertebrae planae), also known as the pancake or silver dollar or coin-on-edge vertebra, is the term given when a vertebral body has lost almost its entire height anteriorly and posteriorly, representing a very advanced compression fracture. Pathology It can occur in a ...
Article

VIPoma

VIPomas are a very rare type of pancreatic endocrine tumor that secrete, and get their name from, vasoactive intestinal peptide (VIP). The clinical syndrome resulting from these tumors is commonly known as WDHA syndrome, as an acronym of the cardinal symptoms of watery diarrhea, hypokalemia, and...
Article

Visceral pleural invasion

Visceral pleural invasion is a feature that can be seen in lung cancers. It is defined as tumor extension beyond the elastic layer of the visceral pleura. It is considered an aggressive sign and one of the most important adverse prognostic factors in non-small cell lung cancers 1. Pathology Gr...
Article

Volcano sign (meningioma)

Volcano sign refers to the appearance of classical meningioma that resembels the appearance of volcano (viewed in cross-section MRI, parallel to dural attachment) in which there is triangular hyperostosis at the base of the meningioma (mountain) with the tumor being the cloud around it. The intr...
Article

Von Hippel-Lindau disease

Von Hippel-Lindau (vHL) disease is characterized by the development of numerous benign and malignant tumors in different organs (at least 40 types 1) due to mutations in the VHL tumor suppressor gene on chromosome 3. Epidemiology The disease is rare with an estimated prevalence of 1:35,000-50,...
Article

Von Hippel-Lindau disease (mnemonic)

Features of von Hippel-Lindau disease can be remembered by the mnemonic: HIPPEL Mnemonic H: hemangioblastoma I: increased risk of renal cell cancer P: pheochromocytoma P: pancreatic lesions (cyst, cystadenoma, cystadenocarcinoma) E: eye dysfunction (retinal hemangioblastoma), endolymphati...
Article

Vulval neoplasms

Vulval neoplasms are rare and mostly seen in elderly female patients. Squamous cell carcinoma (SCC) is the most common malignancy of the vulva and only 30% of them are associated with oncogenic human papillomaviruses (HPVs). Pathology Squamous neoplastic lesions  Premalignant  classic vulvar...
Article

WAGR syndrome

The WAGR syndrome stands for: Wilms tumors (greatly increased risk) aniridia genital anomalies mental retardation Pathology Genetics Occurs from a mutation related to chromosome 11p13 3 which is in close proximity to the WT1 gene.
Article

Waldenström macroglobulinemia

Waldenström macroglobulinemia, previously also known as lymphoplasmacytic lymphoma, is a type of B-cell lymphoma. Terminology Recent publications classify Waldenström macroglobulinemia as a lymphoplasmacytic lymphoma with any level of an IgM paraprotein 10.  Therefore the two entities are not ...
Article

Well differentiated fetal adenocarcinoma of lung

A well-differentiated fetal adenocarcinoma (WDFA) of lung is a rare low grade lung tumor. Some consider this as a variant of adenocarcinoma with others considering this under the group of pulmonary blastomas 5.  According to classification by the World Health Organization in 1999, it was remove...
Article

Whitmore-Jewett staging system

Whitmore-Jewett staging system (also known as the Jewett staging system or ABCD system) is a staging system for prostate cancer. It was developed by the American Urological Association (AUA). Most societies (including AUA) and clinicians now advocate and use the TNM staging system. A: subclinic...
Article

WHO classification of anal margin tumors

The WHO classification of anal margin tumors or perianal skin tumors is: intraepithelial tumors Bowen disease (precursor of squamous cell carcinoma) Paget's disease (precursor of adenocarcinoma) invasive tumors squamous cell carcinoma adenocarcinoma basal cell carcinoma  verrucous carcin...
Article

WHO classification of tumors of hematopoietic and lymphoid tissues

The World Health Organization (WHO) classification of tumors of hematopoietic and lymphoid tissues is the most widely used pathologic classification system for hematolymphoid neoplasms. The current revision, known as the 4th revised edition, was published in 2016, supersedes the 4th edition publ...
Article

WHO classification scheme for thymic epithelial tumors

The WHO classification scheme for thymic epithelial tumors is one of many classifications systems for thymoma and related tumors, and classifies them according to histology: type a medullary thymoma spindle cell thymoma type ab: mixed thymoma type b1: lymphocyte rich predominantly cortical...
Article

WHO criteria in tumor response

The WHO criteria have been developed in the 1980s to standardized reporting of cancers in clinical trial.​ These criteria Nowadays, newer criteria often based on the WHO criteria (such as RECIST, mRECIST, Choi criteria, Lugano response criteria), have widely replaced the WHO criteria in clinical...
Article

WHO histological classification of tumors of the uterine cervix

The WHO histological classification is a detailed classification of tumors of the uterine cervix. epithelial tumors squamous tumors and precursors squamous cell carcinoma, not otherwise specified - 8070/3 keratinizing - 8071/3 non-keratinizing - 8072/3 basaloid - 8083/3 verrucous - 8051/3...
Article

Wilms tumor

Wilms tumor, also known as nephroblastoma, is a malignant pediatric renal tumor. Epidemiology Wilms tumors are the most common pediatric renal mass, accounting for over 85% of cases 1,8 and accounts for 6% of all childhood cancers 2. It typically occurs in early childhood (1-11 years) with pea...
Article

Wilms tumor (staging)

Wilms' tumor staging is largely anatomical and relates to the invasion and spread of the tumor. Where there is invasion or metastasizes, prognosis is poorer. Wilms tumor, is one of the more common childhood malignancies. stage I confined to kidney complete resection possible stage II local ...
Article

Zurich pituitary score

The Zurich pituitary score (ZPS) is a quantitative classification of pituitary adenomas based on coronal T1W magnetic resonance imaging with contrast, although the score can also be obtained with computed tomography. The ZPS is based on the ratio (R) between horizontal tumor diameter over inter...

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