Small cell carcinomas of the bladder are rare bladder cancers with a poor prognosis. Its appearance overlaps other bladder cancers, in particular, urothelial/transitional cell carcinoma.
A very rare tumor, it has been estimated at <0.0001% of bladder cancers. It is thought to have...
Small cell lung cancer (SCLC), also known as oat cell lung cancer, is a subtype of bronchogenic carcinoma separated from non-small-cell lung cancer (NSCLC) as it has a unique presentation, imaging appearances, treatment, and prognosis. SCLCs are neuroendocrine tumors of the lung that rapidly gro...
Previously, small cell lung cancer (SCLC) was not staged in the same manner as non-small cell lung cancer (NSCLC), but since 2013 both are staged using the IASLC (International Association for the Study of Lung Cancer) lung cancer staging system (currently in its 8th edition, published in 2016)....
Soap bubble appearance describes:
A multi-loculated bubbly appearance.
In bone refers to :
an expansile lytic lesion with internal trabeculations and preserved cortex, usually of benign nature
May be used to describe more aggressive lesions
The differential includes:
Mnemonics to remember the causes of soft tissue calcification include:
My GHOSTS 1
TIC MTV 2
My: myositis ossificans
S: scleroderma/connective tissue diseases
T: tumoral calcinosis
S: sarcoma (synovial cell)
Soft tissue chondromas or extraskeletal chondromas are benign soft tissue tumors of hyaline or myxoid cartilage originating in extraosseous and extrasynovial locations commonly found in the hands and feet.
Soft tissue chondromas are rare. They are most commonly seen in middle-aged...
Soft-tissue sarcomas are a heterogeneous group of malignant tumors of mesenchymal origin (sarcoma) that originate from the soft tissues rather than bone. They are classified on the basis of tissue seen on histology. The commoner sarcomas in the adult and pediatric population are listed below.
Solid lesions with enhancement are by far the most commonly encountered appearance of pituitary region masses.
by far the most common entity
typically enhances less vividly than other entities
elevates the dura of the diaphragma sella (as the origin is wi...
Solid periosteal pattern is thought to evolve from single layer and multilayered periosteal reactions, forming a solid layer of mature new bone adjacent to the cortex. It denotes a longstanding pathological process.
It has been associated with:
Solid-predominant adenocarcinoma of the lung with mucin production is a histological subtype of non-mucinous invasive adenocarcinoma of the lung.
In 2011, the International Association for the Study of Lung Cancer (IASLC), American Thoracic Society (ATS), and European Respiratory S...
Solitary bone plasmacytomas is an uncommon plasma cell tumor which is localized to bone. They may involve any bone, but they have a predisposition for the red marrow-containing axial skeleton:
spinal disease is observed in ~50% (range 34-72%) of cases
the thoracic vertebrae are most commonly i...
A solitary pulmonary nodule, according to the Nomenclature Committee of the Fleischner Society, is defined as a rounded opacity, well or poorly-defined on a conventional radiograph, measuring up to 3 cm in diameter and is not associated with lymphadenopathy, atelectasis, or pneumonia.
The differential diagnosis of a solitary sclerotic bone lesion is heavily influenced by the age of the patient, and includes:
solitary either because no others are present or no others have been imaged
enostosis (bone island)
Lymphadenopathy is quite common, and it can be very difficult to differentiate malignant lymphadenopathy from reactive nodal enlargement.
Several gray scale and color Doppler features favor malignancy in a lymph node.
Gray scale parameters that favor malignancy
size: larger - more likely mali...
SpaceOAR is a technique in which a physical space is created between the prostate gland and rectum for electron beam radiotherapy targeted to the prostate gland in cases of prostate cancer.
OAR stands for "organ at risk", and in cases of prostate cancer radiotherapy treatment the rectum is the...
Spermatic cord leiomyosarcomas are uncommon malignant paratesticular masses.
Accounts for ~10% of spermatic cord sarcomas. The average of a patient at presentation is 58 years old (although has been seen as young as 15 years old).
Patients may have left inguina...
Spermatic cord liposarcomas are the most common malignant tumor of the spermatic cord. Most present as painless, slow-growing masses and can be mistaken for inguinal hernias. They are usually well-differentiated and spread by local extension.
In a large population-based registry,...
Spinal astrocytomas are the second most common spinal cord tumor, representing 40% of intramedullary tumors 3. They account for 60% of pediatric intramedullary tumors, making them the most common spinal cord tumor in children 6.
This article specifically relates to spinal astrocytomas. For a di...
The spinal instability neoplastic score (SINS) helps to assess tumor related instability of the vertebral column. It has been shown to useful in guiding the mobilization or operative management of patients with neoplastic spinal disease.
Studies have reported good inter-observer agreement among...
Spinal metastases is a vague term which can be variably taken to refer to metastatic disease to any of the following:
vertebral metastases (94%)
may have epidural extension
intradural extramedullary metastases (5%)
intramedullary metastases (1%)
Each of these are discussed separately. Below...
Spinal paragangliomas are tumors of neuroendocrine origin that rarely involve the central nervous system, usually the filum terminale and cauda equina. They are indolent and considered WHO grade I lesions 5.
Paragangliomas overall are most commonly located within the adrenal gland (pheochromoc...
Spindle cell carcinomas of the lung correspond to a very rare type of non-small cell lung carcinomas (NSCLC) classified under sarcomatoid carcinomas of the lungs.
Although, in the past, some authors also used the term synonymously with pleomorphic carcinoma of the lung, since the ...
Spitz nevus is a rare benign melanocytic lesion, that shares significant clinicohistological commonality with melanoma and maybe difficult to differentiate 2.
History and etymology
This lesion was described by an American pathologist, Sophie Spitz (1910-1956), who worked at Memorial Sloan-Ket...
Splenic lymphoma, also termed as lymphomatous involvement of the spleen, represents the most common malignancy to involve the spleen. They are commonly secondary, rarely being primary (referred as primary splenic lymphoma).
This article focuses on the location-specific primary and secondary l...
Splenic metastases are relatively rare on imaging, although they are more commonly found on autopsy. Typically they are part of a widespread metastatic disease.
The rate of splenic metastases varies between 1-10% of autopsy studies, depending on whether microscopic or macroscopic ...
Splenomegaly refers to enlargement of the spleen. The upper limit of normal adult splenic length is traditionally cited at 12 cm, but lengths upwards of 14 cm can be seen in normal, taller males 7.
Massive splenomegaly is variably defined, including when the spleen is 5 standard deviations abov...
The split bolus technique is a CT imaging investigation used in patients with hematuria aiming to put together, in a single image acquisition, both the nephrographic and renal excretory phases and thus reducing the radiation dose of the study. It is a CT protocol adopted for some institutions fo...
Squamous cell carcinoma of the larynx is the most common primary malignant tumor that affects the laryngeal framework. Typically it is categorized by the laryngeal subsite affected, which affects presentation, treatment and prognosis.
Males are more affected than females, and usu...
Squamous cell carcinoma (SCC) is one of the non-small cell carcinomas of the lung, second only to adenocarcinoma of the lung as the most commonly encountered lung cancer.
Squamous cell carcinoma accounts for ~30-35% of all lung cancers and in most instances are due to heavy smoki...
Squamous cell carcinoma of the penis arises most commonly at the distal end of the penile urethra with local invasion of the glans.
In addition to TNM classification, the following staging is used:
stage I: confined to the glans or foreskin
stage II: invasion of penile shaft
Squamous cell carcinoma of the urinary bladder is rare and accounts for only ~3-8% 1,2 of all bladder cancers (90% are transitional/urothelial cell carcinomas) but nevertheless, SCC is the most common type of non-transitional cell carcinoma involving the bladder 2. SCC of the bladder is observed...
Stereotactic body radiotherapy (SBRT), also known as stereotactic ablative radiotherapy (SABR), is a technique used to treat certain cancers as an alternative to surgical resection. It can be used to treat early lung cancer and hepatocellular carcinoma.
Stereotactic radiosurgery (SRS) was developed based on patient immobilization techniques, such as headframes. 'Stereotactic' refers to the high precision of the treatment system which allows smaller margins and higher doses per treatment 1. SRS involves a smaller number of treatments (typically...
The stipple sign refers to the pointillistic end-on appearance on intravenous pyelography or retrograde pyelography of contrast material tracking into the interstices of a papillary lesion. Because the majority of transitional cell carcinomas (TCC) have a papillary configuration, the presence of...
Stromal tumor of uncertain malignant potential (STUMP) is a rare stromal tumor of the prostate with a broad spectrum of histologic pattern and variable clinical behavior.
Stromal tumor of uncertain malignant potential has been also known as atypical stromal hyperplasia, cystic epit...
Sunburst or sunray appearance describes two separate findings in the bone: a periosteal reaction and a trabeculation pattern. It should not be confused with the sunburst sign of meningioma vascularity.
Sunburst periosteal reaction reflects aggressive periostitis. The sunburst appearance occurs...
Superior vena cava (SVC) obstruction can occur from extrinsic compression, intrinsic stenosis, or thrombosis. Malignancies are the main cause and are considered an oncologic emergency. Superior vena cava syndrome (SVCS) refers to the clinical syndrome with symptoms that results from this obstruc...
Superscan is intense symmetric activity in the bones with diminished renal and soft tissue activity on a Tc99m diphosphonate bone scan.
This appearance can result from a range of etiological factors:
diffuse metastatic disease
transitional cell c...
Sweet syndrome (acute febrile neutrophilic dermatosis) is characterized by a constellation of clinical symptoms, physical features, and pathologic findings which include:
tender erythematous skin lesions (papules, nodules and plaques)
a diffuse infiltrate consisting predom...
Sympathetic chain schwannomas or schwannomas of the cervical sympathetic chain (SCSC) are rare benign nerve sheath tumors. These longitudinally oriented tumors in the perivertebral space rely on anatomical mass effect to differentiate from the main differential masses of vagal schwannoma or spin...
Synchronous breast cancers are two (or more) primary breast cancers that occur in either breast at the same time.
Up to 10% of all breast cancers may be synchronous (particularly found with the use of breast MRI). The occurrence of bilaterality is greatest with invasive lobular c...
The term synchronous is used in oncology to refer to two (or more) independent primary malignancies, when the second (or third, etc.) malignancy arose within six months of the diagnosis of the first malignancy 1,2. These may be in the same, or in different, organs.
Synchronous primary lung carcinoma (SPLC) is a term given to the occurrence of two or more primary lung carcinomas within different portions of the lung in the same time period.
They are thought to the carry the same pathophysiological mechanism as metachronous lung carcinoma (i.e. two or more ...
The syndrome of inappropriate antidiuretic hormone secretion (SIADH or SIAD) (also known as Schwartz-Bartter syndrome) was initially described in patients with lung cancer who developed hyponatremia associated with continued urinary sodium loss. The result is often dilutional hyponatremia in whi...
Synovial sarcomas are relatively common intermediate-to-high grade malignant soft tissue tumors, often with an initial indolent course, affecting young patients, and most commonly involving the soft tissue surrounding the knees.
Synovial sarcomas typically present in adolescents a...
The oncological agent tamoxifen has pro-oestrogenic changes on the endometrium resulting in abnormal growth with an increased prevalence of:
endometrial polyps: occurs in ~8-36% of women in treated 8
endometrial hyperplasia: occurs in ~1-20% of women treated ref
cystic endometrial atrophy
Tamoxifen is an important anti-estrogen agent used for the treatment of hormone receptor-positive breast cancer and it may induce reversible hepatic steatosis. This is usually transient and may occasionally be associated with hepatic dysfunction. It only rarely leads to cirrhosis 1.
T-cell prolymphocytic leukemia (T-PLL) is a rare and unusual hematological malignancy.
It represents around 2% of all mature lymphocytic leukaemias in adults over the age of 30 1. It usually affects older adults with an average age at presentation being around 65 years. There may ...
Technetium agents based on the technetium-99m (Tc-99m) radioisotope are frequently used agents in medical imaging. A radiopharmaceutical labeled with Tc-99m constitutes a co-ordination complex in which ligands bond to a central atom of Tc-99m by co-ordinate covalent bonds 4 .
The radioactive te...
Masking is very important when viewing mammograms, especially with high-density breasts. It helps the adaptation of the eye to the luminance of the mammograms on the viewbox.
The technique of masking allows the comparative study of small areas of both breasts and is a featur...
Temporal lobe epilepsy (TLE) is the most common type of partial epilepsy, with often characteristic imaging and clinical findings. It is divided into two broad groups:
involves the mesial temporal lobe structures
most frequently due to mesial temporal sclerosis
The differential diagnosis for a terminal ileitis is quite extensive, and includes:
inflammatory bowel disease
Crohn disease (most common)
backwash ileitis due to ulcerative colitis
Testicular cancers are the most common neoplasm in men between the ages of 20 and 34 years.
Testicular cancer is uncommon, accounting for less than 1% of all internal organ malignancies 2.
The demographics of affected individuals depends on the age of the histology of the tumor. ...
Testicular embryonal cell carcinoma is a type of non-seminomatous germ cell tumor.
Incidence peaks at around 25-30 years.
It may occur as part of a mixed germ cell tumor (more common and may be present as a component in around 80% of mixed germ cell tumors) or very ra...
Testicular lymphoma is an uncommon testicular malignancy. Lymphoma can involve the testes in three ways:
primary site of extranodal disease (primary testicular lymphoma)
secondary involvement of systemic disease
primary manifestation of subclinical systemic disease
This article is concerned ...
Testicular seminomas are the most common testicular tumors and account for ~45% of all primary testicular tumors. This article concerns itself only with testicular seminomas; however, seminomas can arise outside of the testicle; most often within the anterior mediastinum - see article on anterio...
Testicular teratoma, unlike ovarian teratoma, is often aggressive in its biological behavior, and often exists as part of testicular mixed germ cell tumors.
Pure testicular teratomas account for only 4-9% of all testicular tumors. A similar number are seen in the context of test...
Thoracic lymph nodes are divided into 14 stations as defined by the International Association for the Study of Lung Cancer (IASLC) 1, principally in the context of oncologic staging. For the purpose of prognostication, the stations may be grouped into 7 zones. The IASLC definitions leave some a...
Thorotrast is a suspension of radioactive thorium dioxide first produced in Germany in 1928 and used as a contrast agent until the 1950s. Its principal use was for cerebral angiography: 90% of the estimated 50,000-100,000 patients treated received it for this purpose. Umbrathor was another thori...
Thymic carcinoma is part of the malignant end of thymic epithelial tumors.
Patients are typically 50 to 70 years of age at presentation 9.
The incidence of paraneoplastic syndromes is thought to be low. At least 10 different histologic variants have been described 4. T...
Thymic hyperplasia is a disorder whereby there is hyperplasia of the thymus gland.
Thymus hyperplasia can be subdivided into two forms:
true thymic hyperplasia
lymphoid thymic hyperplasia
Both true thymic hyperplasia and lymphoid hyperplasia manifest as diffuse symmetric enlarge...
Thyroid lymphoma is rare, accounting for a minority of both thyroid malignancies and lymphoma in general.
The thyroid may be affected primarily or secondary to lymphoma elsewhere. This article is concerned with primary thyroid lymphoma.
Thyroid lymphoma accounts for <5% of thyr...
Thyroid malignancies are most commonly primary thyroid cancers but can rarely be metastatic deposits.
Thyroid malignancies can be categorized into the following key subtypes:
primary thyroid cancers
papillary thyroid carcinoma: 60-80% of carcinomas
Thyroid scan (thyroid scintigraphy) is a nuclear medicine examination used to evaluate thyroid tissue.
functional status of a thyroid nodule
thyrotoxicosis: differential diagnosis
whole body scan for distant metastases
estimation of local residual thyro...
The TNM staging system (officially known as the TNM classification system of malignant tumors) is a cancer staging system overseen and published by the Union for International Cancer Control (UICC). The American Joint Committee on Cancer (AJCC) publishes the AJCC Cancer Staging Manual which is b...
Tolosa-Hunt syndrome (THS) is an idiopathic inflammatory condition that involves the cavernous sinus and orbital apex and is essentially a clinical diagnosis of exclusion.
The estimated incidence of Tolosa-Hunt syndrome is 1 per 1,000,000 person years with an average age of onset ...
Total pelvic exenteration refers to extensive surgical resection of pelvic structures to treat locally advanced or recurrent pelvic malignancies. It is performed to obtain optimal excision of tumor radical margins which can be difficult in pelvis given proximity and often local invasion of adjac...
The TP53 gene, located on chromosome 17, is a tumor suppressor gene, responsible for the production of the p53 protein, a transcription regulatory protein which works in concert with a number of other proteins, together forming the p53 pathway 1,2.
Inherited mutations in this gene result in the...
The differential for tracheal masses can be rather wide.
For a single mass consider:
direct invasion from adjacent organ (lung, thyroid, esophagus and larynx)
distant metastasis (e.g. melanoma, breast, renal, and colon cancer)
squamous cell carcinoma: commone...
Trachelectomy, also known as a cervicectomy, refers to surgical resection of the uterine cervix. It may be considered as a fertility-sparing treatment for low-stage cervical cancer.
Although radical hysterectomy is routine for treatment of endometrial and more advanced cervical cancer, uterine-...
Tram-track sign refers to the parallel thickening and enhancement around the optic nerve, and is most frequently seen in the setting of optic nerve meningioma. It may, however, also be seen in 1:
Transcoelomic spread describes the spread of a malignancy into body cavities that occurs via penetrating the surface of the peritoneal, pleural, pericardial, or subarachnoid spaces. For example, ovarian tumors can spread transperitoneally to the surface of the liver.
Transitional cell carcinoma of the bladder staging uses the TNM system which has replaced the previously widely used Jewett-Scott-Marshall tumor staging system. It is very similar to the staging of TCC of the renal pelvis and staging of TCC of the ureter.
Ta: non-invasive papill...
Transitional cell carcinoma (TCC) of the renal pelvis, also called urothelial cell carcinoma (UCC) of the renal pelvis, is uncommon compared to renal cell carcinoma and can be challenging to identify on routine imaging when small.
This article concerns itself with transitional cell carcinomas ...
Staging of transitional cell carcinomas of the urinary tract vary according to the location of the tumor, and are staged using the TNM staging system.
transitional cell carcinoma of the renal pelvis
transitional cell carcinoma of the ureter
transitional cell carcinoma of the bladder
Transitional cell carcinoma (TCC) of the ureter, also called urothelial cell carcinoma (UCC) of the ureter, are uncommon compared to similar tumors elsewhere along the urinary tract but are nonetheless the most common primary tumor of the ureter.
This article concerns itself with transitional c...
Transitional cell carcinoma (TCC), also called urothelial cell carcinoma (UCC), is the most common primary malignancy of the urinary tract and may be found along its entire length, from the renal pelvis to the bladder.
As imaging findings and treatment vary according to where along the urinary...
Transplantation of a transverse rectus abdominis myocutaneous (TRAM) flap is a commonly used surgical procedure for breast reconstruction following mastectomy.
An autologous myocutaneous flap consisting of abdominal skin, subcutaneous fat, the rectus abdominis muscle, and adjoining vasculature ...
Trichoptysis (rare plural: trichoptyses) is an extremely rare symptom, whereby patients cough up hair. It is highly specific for rupture of a mediastinal teratoma into the tracheobronchial tree, however it is not pathognomonic as several articles claim (see below) 1,2. Nevertheless it remains a ...
Triple receptor-negative (TRN) breast cancer or triple-negative breast cancer (TNBC) is a subtype of breast cancer characterized by a relative absence of immunohistochemical staining for the following hormone receptors/protein:
estrogen receptor (OR)
progesterone receptor (PR)
Trousseau syndrome (not to be confused with Trousseau sign) represents the association between migratory thrombophlebitis and malignancy, particularly mucin-producing tumors; hence one of its other names: cancer-associated thromboembolism 1.
History and etymology
Armand Trousseau (1801-1867),...
Tuberculosis of the central nervous system can result from either hematogenous spread from distant systemic infection (e.g. pulmonary tuberculosis) or direct extension from local infection (e.g. tuberculous otomastoiditis).
Intracranial manifestations of tuberculosis are protean and can affect ...
Tuberculous cervical lymphadenitis, also known as scrofula and king's evil, continues to be seen in endemic areas and in the industrialised world particularly among the immunocompromised.
Tuberculous cervical lymphadenitis is the most common manifestation of extrapulmonary tubercu...
Tubulocystic renal cell carcinomas are a rare subtype of renal cell carcinoma (RCC) with predominantly cystic appearance.
Tubulocystic RCC was first identified as a distinct histopathologic entity in 2005, and subsequently acknowledged as an independent disease category in the 2016...
Tumor ablation, or image-guided tumor ablation, is the direct application of chemical or energy-based (i.e. thermal and nonthermal) treatments to cause local tumor destruction. Techniques include:
radiofrequency ablation (RFA)
microwave ablation (MWA)...
Tumor lysis syndrome (TLS) is situlation representing a constellation of laboratory and clinical derangements inclusive of
It is considered an oncological emergency can occur following treatment of malignancies with high cellul...
Tumor markers are a group of molecules in serum that are elevated in various malignancies and are often used to monitor treatment response as well as alert for potential progressive disease when in remission.
Commonly used markers include:
AFP (alpha fetoprotein)
Tumor pseudoprogression, also known just as pseudoprogression, corresponds to an increase of lesion size related to treatment, which simulates progressive disease. The term is largely used in brain tumors imaging follow-up, especially for high grade gliomas (e.g. glioblastoma), and is observed a...
Tumor pseudoresponse, also known just as pseudoresponse, refers to the phenomenon of tumors appearing to respond to a specific treatment on imaging criteria, when the lesion actually remains stable or has even progressed.
The term is largely used in brain tumors imaging follow-up, especially fo...
There are a number of tumors of muscular origin, which overall are relatively uncommon, representing ~2% of benign soft tissue tumors and ~10% of malignant soft tissue tumors 1.
The tumors can be divided according to the type of muscle fiber:
Skeletal muscle origin
Tumors of the male urethra are uncommon. They can be categorized both on the grounds of histology and location.
squamous cell carcinoma of the urethra: 80%
urothelial/transitional cell carcinoma of the urethra: 15% (predominantly posterior urethra)
adenocarcinoma of the urethra: 5%...
Tumors of the seminal vesicles usually represent contiguous invasion of the seminal vesicles from malignancies in adjacent organs, most commonly the prostate. Tumors originating de novo within the seminal vesicles themselves are much rarer.
adenocarcinoma of the seminal vesic...
Tumor spread through air spaces (STAS) is a relatively recently recognized pattern of invasion in lung adenocarcinoma. According to the 2015 WHO classification, STAS is defined as “micropapillary clusters, solid nests, or single cells spreading within air spaces beyond the edge of the main tumor...