Renal large cell neuroendocrine carcinomas are an extremely rare renal tumor, with only six cases reported in the literature (c. 2022) 1.
Renal large cell neuroendocrine carcinoma represents <1% of the total reported cases of primary renal cancers. The most affected population i...
Radiation therapy has the potential to cause complications in many organ systems, many of which, especially in the thorax, are important for radiologists to be aware of.
acute radiation syndrome
complications of cranial radiation therapy
radiation-induced cerebral vasculopathy
Salivary duct carcinomas are a subtype of primary salivary gland tumor. Salivary duct carcinomas show high rates of metastasis and recurrence.
Salivary duct carcinomas represent 5-10% of salivary gland malignancies and can arise de novo or out of a pleomorphic adenoma 1,2. They t...
The Bone Reporting and Data System (Bone-RADS) is an algorithm developed and proposed by the Practice Guidelines and Technical Standards Committee of the Society of Skeletal Radiology for the diagnostic workup of incidentally encountered solitary bone lesions in adults on MRI and/or CT 1.
Alpha-fetoprotein (AFP) in the cerebrospinal spinal fluid (CSF) has been reported as a tumor marker for some intracranial tumors with yolk sac elements, and teratoma 1.
intracranial yolk sac tumor
intracranial embryonal carcinoma
congenital CNS tumors with yolk sac ...
The sea anemone sign is a unique (but not wholly exclusive) appearance seen in ovarian serous surface papillary borderline tumors (SSPBT). It refers to its surface stroma frequently branches into exophytic papillary stalks, macroscopically 1.
On cross-sectional imaging, p...
Radiologic tumor pseudoprogression on imaging denotes an imaging appearance of tumor response where the tumor first exhibits findings suggestive of progression (i.e. growth, new lesions). However, during sustained therapy, response is eventually demonstrated 1.
With the advent of ...
Intraparotid nodal metastases refer to metastatic involvement of intraparotid lymph nodes from either a primary parotid tumor or an extraparotid tumor in the head and neck (e.g. nasopharyngeal carcinoma).
There may be a predilection towards the superficial lobe or tail regi...
The ADNEX (Assessment of Different NEoplasias in the adneXa) model is a risk model developed by the IOTA (International Ovarian Tumor Analysis) group to differentiate benign and malignant neoplasms of the ovary and, among them, four different subgroups (borderline, stage I cancer, stage II-IV ca...
Peripheral T cell lymphoma is an uncommon, heterogeneous group of lymphoma. It can account for around 5-15% of non-Hodgkin lymphoma (NHL).
The word "peripheral" does not mean involvement in the extremities but refers to tumor cells that arise from lymphoid tissue outside of the bon...
The World Health Organizatiοn classification of skin tumors is the most widely used pathologic classification system for skin tumors. The most recent edition is the 4th, which was published in 2018 1. The radiologically relevant and common entities are reflected below.
Submandibular gland enlargement refers to an increase in the volume of the submandibular gland, exceeding "normal" values of 7.4 ± 1.8 mL 1.
submandibular duct stenosis (e.g. tumor, granulomatous disease)
acute sialadenitis: following ...
The salt and pepper sign is used to describe a typical MRI appearance of some highly vascular tumors which contain foci of hemorrhage, typically a paraganglioma 1-3. The appearance is on T1-weighted sequences, and is made up of:
punctate regions of hyperintensity = salt
small flow voids = pepp...
Polymorphous low-grade neuroepithelial tumor of the young (PLNTY) is an epileptogenic tumor of children and young adults.
First described in 2016 1, polymorphous low-grade neuroepithelial tumor of the young has been recently included in the new family of "pediatric-type" low-grade ...
Cachexia is a syndrome of metabolic dysfunction secondary to an underlying disease in which there is depleted skeletal muscle (sarcopenia) which may or may not be accompanied by an absolute loss of body fat.
Cancer cachexia is specifically used to refer to the cachexia associated ...
Fibrosing inflammatory pseudotumors are an inflammatory process with histology showing a polymorphous infiltrate with plasma cells, lymphocytes and eosinophils as well as a significant reactive fibrovascular component.
They can occur at various sites of the body including: ...
Night sweats, also known as sleep hyperhidrosis, are a common clinical complaint and may herald malignancy, especially lymphoma, or infections. Patients typically report waking up in the night with sweating so severe that their clothes and bed sheets are soaked through ("drenching sweats") and n...
A blast crisis or lymphoid blast crisis refers to the transition of chronic or accelerated phase chronic myeloid leukemia to acute leukemia. It is usually characterized by
≥30% blasts in the bone marrow or peripheral blood
development of extramedullary disease outside of the spleen
Rectal MRI is a key imaging investigation in the diagnosis, staging and follow up of rectal cancer. An increase in the utility of rectal MRI as been driven by the recognition of the mesorectum as a distinct anatomic compartment containing and limiting the margins of the rectum, and forming a sur...
Pembrolizumab induced pneumonitis is a form of drug-induced lung disease occurring as a result of a response to the use of the programmed cell death protein 1 (PD1) inhibitor pembrolizumab. It may have variable pattern 2.
Pembrolizumab is also reported to have a high risk of inducing lung inju...
Clear cell papillary renal cell carcinoma is a subtype renal cell carcinoma.
Generally uncommon but thought to be the fourth most common histologic type of renal cell carcinoma at the time of new classification (c. 2016) 1.
This subtype is characterized by low-grade, c...
Fluid-fluid levels in liver lesions are a rare appearance of both benign and malignant conditions.
complicated hepatic cyst 2
hepatic abscess 2
chronic hepatic hematoma 3
biliary cystadenoma 3
hepatic hemangioma (very rare) 2
Carcinoma of the Littré glands is rare. The Littré (urethral) glands of the penis may be the origin of cancers of the penis, usually adenocarcinomas 1.
There are only a few scattered case reports of true Littré gland malignancy, although it is probably under-reported due to the fa...
Hepatic small vessel neoplasms (HSVN) are low-grade vascular lesions of uncertain malignant potential.
Although also referred to as hepatic small vessel hemangiomas 3, this term may wrongly mislead HSVN to represent a subtype of hepatic hemangiomas and, therefore, will be avoided ...
The solitary fibrous tumor of the orbit is a rare spindle-cell neoplasm originating from mesenchymal fibroblast-like cells histologically identical to solitary fibrous tumors found elsewhere
Solitary fibrous tumors occur in a wide age range reported from 9 to 76 years without a co...
Immunosuppression is the impairment of the body's immune system which can alter the ability of the body's defense mechanisms to prevent diseases, particularly certain infections, including opportunistic infections, and cancers.
Patients with immunosuppression are said to be immuno...
Oncocytic sinonasal papillomas (OSP) or cylindrical cell papillomas are a rare form of Schneiderian papillomas and benign epithelial sinonasal tumors arising from the Schneiderian epithelium of the nasal cavity and paranasal sinuses.
Oncocytic sinonasal papillomas are the least fr...
Primary intraosseous carcinomas NOS (PIOC) are malignant epithelial odontogenic neoplasms of the jawbones with no clear benign analog.
Primary intraosseous carcinomas are rare tumors 1-4. They occur in a wide age range with the mean in the sixth decade of life. Men are more freque...
Ameloblastic carcinomas or malignant ameloblastoma are malignant epithelial odontogenic neoplasms with histologic features ameloblastoma.
Ameloblastic carcinomas are rare tumors approximately accounting for 1% of jaw tumors 1,2. They have been found in a wide age range and are mor...
Alcian blue stain is a histological stain utilized for the identification of extracellular matrix proteoglycans, like glycosaminoglycans and hyaluronic acid 1, commonly in connective tissue and epithelial malignant neoplasms 2, and also Barrett esophagus, where it can highlight mucosal intestina...
Giemsa stain is a commonly used histological stain that colors the cytoplasm blue to pink (depending on its acidity) and the nucleus blue to black 1. It serves as the diagnostic gold standard of histopathological staining of blood samples from patients with plasmodium-borne malaria, and as the b...
Tobacco abuse, most commonly by smoking cigarettes, is a legal drug habit of many throughout the world. It is a significant risk factor for many malignancies, respiratory and cardiovascular diseases and is a major cause of premature mortality throughout the world.
It has been esti...
Dentinogenic ghost cell tumors (DGCT) are benign mixed epithelial and mesenchymal odontogenic tumors with locally aggressive behavior.
It is also known as the 'solid' or 'neoplastic form of calcifying odontogenic cyst’, since the 4th WHO classification of head and neck tumors in 20...
Squamous cell carcinoma (SCC) of the penis is an uncommon condition that often presents at an advanced stage. Imaging is more often used for staging than for the initial diagnosis. It is the commonest histological subtype of penile cancer.
Penile cancer is a relatively infrequent ...
Hairy cell leukemia is a rare and indolent form of small mature B-cell leukaemias.
Its annual incidence is estimated at around 0.3 cases per 100 000, and the disease comprises 2-3% of all leukaemias. There is a recognized male predilection of around 4:1 with a median age of around...
Mixed germ cell tumors of the mediastinum or mediastinal mixed germ cell tumors are malignant non-seminomatous germ cell tumors of the mediastinum consisting of more than one type of germ cell tumor.
The term ‘malignant teratoma’ is not recommended.
Mixed germ cell t...
Aerogenous metastases are a rare form of metastases that can occur in the lung due to aerogenous spread along the airways.
Aerogenous metastases are usually from primary lung cancer disseminating along the airways from a different part of the lung and less commonly from other parts o...
Mediastinal choriocarcinomas or choriocarcinomas of the mediastinum are malignant non-seminomatous germ cell tumors of the mediastinum consisting of trophoblastic cells.
Pure choriocarcinomas are rare and account for up to 3% of primary mediastinal germ cell tumors 1. They usually...
Mediastinal embryonal carcinomas or embryonal carcinomas of the mediastinum are malignant non-seminomatous germ cell tumors with embryonal type cells primarily growing in the mediastinum.
Mediastinal embryonal carcinomas are very rare mediastinal tumors accounting for up to 8% of ...
Mediastinal yolk sac tumors or yolk sac tumors of the mediastinum are malignant non-seminomatous germ cell tumors primarily growing in the mediastinum.
The term ‘endodermal sinus tumor’ is not recommended.
Mediastinal yolk sac tumors are rare mediastinal tumors. In a...
Mediastinal seminomas or mediastinal germinomas are primary malignant germ cell tumors of the mediastinum.
Mediastinal seminomas are rare mediastinal tumors and account for up to one-third of primary malignant mediastinal germ cell tumors 1. They are almost only found in males ≥10...
Neoplasms, also known as tumors, are pathological masses, caused by cells abnormally proliferating and/or not appropriately dying. Neoplasms may be either benign or malignant. Malignant neoplasms are synonymous with cancers.
clear origin (unless very large)
Cystic tumors of the atrioventricular node (CTAVN), also known as endodermal heterotopia, refer to a benign mass lesion of the atrioventricular node that constitutes a developmental endodermal rest.
A term that is no longer recommended for use is ‘mesothelioma of the atrioventricul...
Cardiac undifferentiated pleomorphic sarcomas are highly malignant mesenchymal tumors of the heart.
Terms that are no longer recommended for use include ‘intimal sarcoma’, ‘undifferentiated sarcoma’ and ‘undifferentiated spindle cell sarcoma’ 1.
Cardiac leiomyosarcomas are malignant smooth muscle tumors of the heart.
Cardiac leiomyosarcomas are rare primary malignant tumors of the heart accounting for less than one-fifth of cardiac sarcomas. They have been found in a wide age range from 6 months to 86 years with a mean ag...
Dedifferentiated chordomas are biphasic malignant tumors composed of notochordal and high-grade sacomatous components.
Dedifferentiated chordomas are very rare tumors that might be seen in recurrences or after radiotherapy 1-3.
The diagnosis is based on typical imaging...
Poorly differentiated chordomas are highly aggressive poorly differentiated notochordal tumors with a loss of SMARCB1 expression.
Poorly differentiated chordomas are very rare tumors typically seen in children and young adults under the age of 30 years. Females are more frequently...
Lymphoma of the bone may represent lymphoma that has originated within that bone itself i.e. primary, or metastasized there from another organ/tissue, i.e. secondary. Secondary forms of bone lymphoma are much more common than the primary bone form.
primary osseous lymphoma
secondary osseous ly...
Secondary osteosarcomas are osteosarcomas growing on abnormal bone in the setting of various underlying osseous disorders.
Other acceptable terms include Paget sarcoma, osteosarcoma in Paget disease of bone or radiation-associated osteosarcoma, if applicable. The terms postirradiat...
Small cell osteosarcomas (SCOS) are a rare subtype of osteosarcoma characterized by the production of small round cells.
Small cell osteosarcomas account for approximately 1.5% of osteosarcomas. They occur mainly in young adolescents with a mild female predilection but have been f...
CIC-rearranged sarcomas or CIC-DUX4 sarcomas are aggressive undifferentiated small round cell sarcomas with CIC-gene fusions most frequently CIC-DUX4. It is an ultra-rare high grade undifferentiated sarcoma, distinct in terms of clinical presentations and molecular characteristics 6.
Genetic tumor syndromes of soft tissue and bone are a group of genetic disorders and disease syndromes associated with neoplasms that display different features than their sporadic counterparts. These genetic syndromes have been classified separately by the World Health Organization (WHO) and co...
Undifferentiated small round cell sarcomas of bone and soft tissue are a group of malignant bone and soft tissue tumors characterized by small round cell morphology. They comprise the following tumors 1:
round cell sarcoma with EWSR1-non-ETS fusions
Sarcomas with BCOR genetic alterations or BCOR sarcomas are uncommon malignant undifferentiated small round cell tumors of soft tissue and bone characterized by BCOR genetic alterations and comprise sarcomas with BCOR-related gene fusions as BCOR-CCNB3 sarcomas and other BCOR-rearranged sarcomas...
Fibrocartilaginous mesenchymomas are very rare locally aggressive mesenchymal bone tumors seen in children and adolescents.
Fibrocartilaginous mesenchymomas are very rare tumors. They occur in children, adolescents and young adults up to the third decade 1-3. The male gender is sl...
Staging of gallbladder cancer is often done according to the AJCC / TNM.
Tis: tumor only in the epithelium (the inner layer of the gallbladder) and has not grown into deeper layers of the gallbladder
T1: tumor has grown into the lamina propria or the muscle layer (muscularis...
The CT chest-abdomen-pelvis protocol serves as an outline for an examination of the trunk covering the chest, abdomen and pelvis. It is one of the most common CT examinations conducted in routine and emergencies. It can be combined with a CT angiogram.
Note: This article aims to frame a genera...
The CT abdomen-pelvis protocol serves as an outline for an examination of the whole abdomen including the pelvis. It is one of the most common CT protocols for any clinical questions related to the abdomen and/or in routine and emergencies. It forms also an integral part of trauma and oncologic ...
The CT pancreas protocol serves as an outline for a dedicated examination of the pancreas. As a separate examination, it is usually conducted as a biphasic contrast study and might be conducted as a part of other scans such as CT abdomen-pelvis, CT chest-abdomen-pelvis.
Note: This article aims...
The CT pelvis protocol serves as an outline for the acquisition of a pelvic CT. As a separate examination, it might be performed as a non-contrast or contrast study or might be combined with a CT hip or rarely with a CT cystogram. A pelvic CT might be also conducted as a part of other scans such...
Myelodysplastic syndrome / myeloproliferative neoplasm (MDS/MPN) overlap syndromes refer to a group of chronic clonal myeloid malignancies in which there are features of both myelodysplastic syndrome and myeloproliferative neoplasm at the time of presentation.
Entities that can fall into this g...
Prostatic atrophy is characterized by reduced cytoplasm prostatic acinar cells and constitutes a benign mimic of prostate cancer not only on imaging but also histologically.
The term 'proliferative inflammatory atrophy (PIA)' is used if it is associated with inflammation.
Prostatic leiomyomas are benign mesenchymal tumors of the prostate.
Prostatic leiomyomas are very rare 1-3.
The diagnosis of prostatic leiomyoma is based on histology.
Prostatic leiomyomas can present with voiding difficulties or obstructive sym...
Seminal vesicle cystadenomas are a benign subgroup of mixed epithelial and stromal tumors of the seminal vesicles.
Benign tumors of the seminal vesicles are very rare and so are cystadenomas 1.
Voiding difficulties or hematuria have been reported as clinica...
Seminal vesicle stones or calculi refer to solid mineralized pieces of material within the seminal vesicles.
Seminal vesicle calculi are rare and have been mainly reported after the age of 40 years 1.
Seminal vesicle calculi are often associated with hematospermia.
Prostatic acid phosphatase (PAP) also known as prostatic specific acid phosphatase (PSAP) is an enzyme generated by prostatic glandular tissue.
It can be used in immunohistochemistry to identify prostatic tissue including prostatic epithelium and prostatic ducts and is usually expressed ...
Mucinous adenocarcinomas of the prostate or colloid adenocarcinomas of the prostate are a variant of acinar adenocarcinoma and characterized by mucinous features.
Mucinous adenocarcinomas of the prostate are rare and account for less than 0.5% of prostate cancers 1-4.
Adenocarcinomas of the seminal vesicles are the most common malignant primary neoplasm of the seminal vesicles.
Primary adenocarcinoma of the seminal vesicles are very rare 1,2 and can be observed at a wide age range 2.
The following modified diagn...
Basal cell carcinoma of the prostate or prostatic adenoid basal proliferation of uncertain significance is a type of prostate cancer resembling adenoid cystic carcinoma of the salivary glands.
Other terms include 'adenoid cystic carcinoma', 'adenoid basal cell tumor', 'adenoid cyst...
Squamous neoplasms of the prostate include squamous cell carcinomas and adenosquamous carcinomas of the prostate that account for two separate entities in the WHO classification of prostate tumors.
Squamous cell carcinomas of the prostate are very rare and encompass <1% of prostat...
Urothelial carcinomas or transitional cell carcinomas of the prostate are malignant neoplasms that can occur as primary cancers of the prostate gland.
Prostatic urothelial carcinomas account for less than 2-4% of all prostate cancers 1 and are usually seen in middle-aged men 2.
High-grade prostatic intraepithelial neoplasia (HGPIN) refers to a proliferation of glandular epithelial cells and is generally considered a nonobligatory precursor lesion of invasive prostate cancer.
High-grade prostatic intraepithelial neoplasia is diagnosed in core needle biops...
Intraductal carcinomas of the prostate (IDCP) are a new subtype of prostate cancer that has been included as a new entity in the WHO classification of prostate tumors in 2016.
Intraductal carcinomas of the prostate are rarely found isolated on needle core biopsy samples in 0.1-0.3...
Ductal adenocarcinomas of the prostate or prostatic ductal adenocarcinomas are malignant glandular neoplasms of the prostate and tend to be more aggressive than acinar adenocarcinomas.
Due to its morphologic resemblance, it has been formerly referred to as 'endometrial' or 'endomet...
Adenocarcinoma of the prostate with neuroendocrine differentiation is a malignant neuroendocrine tumor of the prostate which only differs from acinar or ductal adenocarcinoma on immunohistochemistry staining.
The diagnosis of adenocarcinoma of the prostate with neuroendocrine differe...
Well-differentiated neuroendocrine tumors of the prostate also known as low-grade neuroendocrine carcinoma of the prostate or carcinoid tumors of the prostate are low-grade neuroendocrine tumors arising from the prostate that may metastasize.
Well-differentiated neuroendocrine tum...
Large cell neuroendocrine carcinomas (LCNEC) of the prostate or prostatic large cell neuroendocrine carcinomas are very aggressive and rare high-grade neuroendocrine tumors that are usually observed in the presence of an already existing adenocarcinoma and very rarely found alone.
A right hemicolectomy is a surgical procedure to remove the cecum and ascending colon.
cancer of the appendix, cecum or ascending colon (most common) 1
inflammatory bowel disease, particularly Crohn disease
perforation of the right colon
Theranostics (or theragnostics 6) uses a diagnostic examination to determine if a patient may benefit from a specific therapeutic drug and thus couples the therapy with diagnostic information specific for the intended target 2.
Theranostics promises improved patient selection for therapy on the...
Small cell carcinomas of the prostate (SCCP) or small cell neuroendocrine carcinomas of the prostate are neuroendocrine tumors and are characterized by aggressive behavior and a proliferation of small cells.
Small cell neuroendocrine carcinomas of the prostate are rare 1,2 and mak...
Prostate imaging recurrence reporting (PI-RR) or prostate MRI for local recurrence reporting is a structured reporting scheme similar to the Prostate Imaging-Reporting and Data System (PIRADS) v2.1 on multiparametric prostate MRI for the detection of local recurrence after radical prostatectomy ...
Pancreatic acinar cell carcinoma is a rare exocrine neoplasm that comprises ~1% of all pancreatic tumors. This tumor shows more aggressive behavior than the far more common adenocarcinoma 1,3,4.
High levels of serum lipase, due to hypersecretion syndrome, resulting in sub...
Neuroendocrine carcinoma of the cervix is a rare type of invasive cervical cancer. These are very aggressive tumors with rapid lymph nodal metastasis 1,2.
Neuroendocrine carcinomas of the cervix account for approximately ~2% of tumors of the cervix seen in the females of reproduct...
Neoplastic pericardial disease, neoplastic pericardial involvement or neoplastic pericarditis refers to a pericardial infiltration by tumor cells usually associated with a variably sized pericardial effusion and is a form of non-infectious pericarditis. It needs to be differentiated from other c...
Ischemic fasciitis refers to a reactive pseudosarcomatous fibroblastic or myofibroblastic proliferation associated with physical constraints.
Terms that are no longer recommended for use include ‘pseudosarcomatous fibromatosis’ and ‘atypical decubital fibroplasia’.
Parathyromatosis (plural: parathyromatoses) is the very rare phenomenon in which there is hyperplasia of residual foci of parathyroidal soft tissue after surgical parathyroidectomy resulting in recurrent hyperparathyroidism.
Parathyromatosis is very rare, a study from 2012 stated ...
Angiofibromas of soft tissue are benign fibroblastic soft tissue neoplasms permeated by a vascular network that might be found in the periarticular and articular areas of the lower extremities that have been included as a separate entity into the WHO classification of soft tissue tumors in 2020....
Mnemonics to remember the classic triad of multiple endocrine neoplasia type 1 (MEN1) are:
P: pituitary adenoma: prolactinoma is commonest
P: pancreatic endocrine tumors
P: parathyroid proliferative disease
parathyroid hyperplasia (most common)
Atypical spindle cell/pleomorphic lipomatous tumors or atypical spindle cell lipoma are benign adipocytic soft tissue neoplasms with a variable proportion of atypical spindle cells, pleomorphic cells adipocytes and other cells with no risk for dedifferentiation but a low risk of local recurrence...
Intramuscular angiomas or intramuscular hemangiomas are benign vascular soft tissue tumors consisting of benign vascular channels within the skeletal muscle.
The term 'intramuscular-infiltrating angiolipoma' is now discouraged.
Intramuscular angiomas are uncommon and...
Extrarenal rhabdoid tumors, also known as rhabdoid tumors of soft tissue or malignant rhabdoid tumors are highly malignant neoplasms of uncertain differentiation mainly seen in infants and children.
Extrarenal rhabdoid tumors are very rare and most are found in infants and childre...
Haemosiderotic fibrolipomatous tumors or haemosiderotic fibrohistiocytic lipomatous lesions are locally aggressive soft tissue tumors of uncertain differentiation.
Haemosiderotic fibrolipomatous tumors are rare with an estimated incidence of less than 0.2% of all benign lipomatous...
Pleomorphic hyalinizing angiectatic tumors (PHAT) of soft parts are locally recurring non-metastasizing neoplasms of intermediate biologic potential and are classified as soft tissue tumors of uncertain lineage.
Pleomorphic hyalinizing angiectatic tumors of soft parts a very rare ...