A mediastinal pseudocyst is the extension of pancreatic pseudocyst into the posterior mediastinum through oesophageal or aortic hiatus or rarely through the foramen of Morgagni. It is a rare complication of acute or chronic pancreatitis.
It can present with symptoms due t...
Aortic dissection is the most common form of the acute aortic syndromes and a type of arterial dissection. It occurs when blood enters the medial layer of the aortic wall through a tear or penetrating ulcer in the intima and tracks along the media, forming a second blood-filled channel within th...
GATA2 deficiency is a germ-line disease expressed as a wide spectrum of phenotypes, including monocytopenia, myelodysplasia, myeloid leukaemias, and lymphoedema. It is a rare cause of pulmonary alveolar proteinosis.
GATA2 deficiency has considerably variable clinical mani...
Swyer-James syndrome (SJS), also known as Swyer-James-MacLeod syndrome and Bret syndrome, is a rare lung condition that manifests as unilateral hemithorax lucency as a result of postinfectious obliterative bronchiolitis.
The condition typically follows a viral respiratory infecti...
A cardiac bronchus is a rare anatomic variant of the tracheobronchial tree, arising from the medial aspect of the bronchus intermedius.
This anomaly is rare and is reported in ~0.3% (range 0.09-0.5%) of individuals 3-5. There may be a predilection for males.
Ganglioneuromas are fully differentiated neuronal tumours that do not contain immature elements and potentially occur anywhere along the peripheral autonomic ganglion sites.
On imaging, usually, they present as well-defined solid masses and can be quite large at presentation. Generally, they a...
Pulmonary hyalinising granuloma (PHG) is a rare, non-infectious, benign fibrosing lesion of the lung. It can sometimes mimic pulmonary malignancy.
Most patients (~ 75% 6) with pulmonary hyalinising granulomas can be symptomatic with it. Commonly reported symptoms include ...
Scleroderma, also known as systemic sclerosis, is an autoimmune connective tissue disorder characterised by multisystem fibrosis and soft tissue calcification. As such, it affects many separate organ systems, which are discussed separately:
musculoskeletal manifestations of scleroderma
Malignant pleural disease usually heralds a poor prognosis, whether it represents a primary pleural malignancy or metastatic involvement.
Clinical presentation is variable. Patients may be asymptomatic or have pleuritic pain. If associated with a sizeable pleural effusio...
Mediastinal lipomatosis refers to a condition where there is a deposition of a large amount of mature adipose tissue in the mediastinum. It is a relatively common benign cause of mediastinal widening.
It is the result of increased deposition of normal unencapsulated fat 1.
Mediastinal lymphoma is common, either as part of disseminated disease or less commonly as the site of primary involvement.
Lymphomas are responsible for approximately 15% of all primary mediastinal masses, and 45% of anterior mediastinal masses in children 1. Only 10% of lymphoma...
Meconium aspiration occurs secondary to intrapartum or intrauterine aspiration of meconium, usually in the setting of fetal distress, and usually in term or post-term infants.
Aspirated meconium can cause small airways obstruction and a chemical pneumonitis.
Marijuana (cannabis or bong) lung refers to the presence of large apical bullae in patients who regularly smoke marijuana. A definite causative link between smoking marijuana and bullous lung disease has not been established, and the association may just be coincidental.
Major aortopulmonary collateral arteries (MAPCAs) are persistent tortuous fetal arteries that arise from the descending aorta and supply blood to pulmonary arteries in the lungs usually at the posterior aspect of hilum.
Embryologically, the intersegmental arteries regress with the no...
Flail chest or flail thoracic segment occurs when three or more contiguous ribs are fractured in two or more places. Clinically, a segment of only one or two ribs can act as a flail segment, hence there is some controversy between the clinical and radiological definitions.
Focal lymphoid hyperplasia of the lung refers to an abnormal accumulation of non-malignant lymphocytic aggregates within the lung.
Previously known as pulmonary pseudolymphoma.
Clinical features can vary from being asymptomatic to various symptoms such as w...
Fibrotic non-specific interstitial pneumonitis is a histological subtype of non-specific interstitial pneumonitis (NSIP). It is considered the more common form 1. This pattern manifests as chronic interstitial inflammation obscured by interstitial fibrosis (with dense collagen), a temporal homog...
Fibrothorax is defined as fibrosis within the pleural space, and occurs secondary to the inflammatory response to one of the following events:
tuberculosis / tuberculous pleuritis: mainly as a late sequela 3
asbestos-related pleural disease
Perforating branches of the internal thoracic arteries arise from the paired internal thoracic arteries (also known as internal mammary arteries) and run in the superior six intercostal spaces. These arteries pierce the internal intercostal muscles and pectoralis major, contributing to the blood...
Fat embolism syndrome (FES) is a rare clinical condition caused by circulating fat emboli leading to a multisystemic dysfunction. The classical clinical triad consists of:
It occurs in ~2.5% (range 0.5-4%) of th...
Pectus carinatum, otherwise known as a pigeon chest, refers to a chest wall deformity in which the sternum protrudes anteriorly. It is less common than pectus excavatum.
Patients may present with dyspnoea and exercise intolerance.
Endogenous lipoid pneumonia, also known as idiopathic lipoid pneumonia, is of the of the two types of lipoid pneumonias. It is also sometimes known as “cholesterol pneumonia” or “golden pneumonia”
Please refer to the main article for a broad discussion, including clinical presentation, radiogra...
Currarino-Silverman syndrome is a rare disorder characterized by high carinate chest deformity caused by premature fusion of manubrio-sternal joint and the sternal segments. It is frequently associated with congenital heart disease.
It occurs more frequently in boys than girls. The majority of ...
Tracheobronchial papillomatosis refers to the occurrence of multiple squamous cell papillomas involving trachea and bronchi. It is an unusual manifestation of recurrent respiratory papillomatosis (RRP), itself a rare condition where HPV-associated papilloma form along the aerodigestive tract8.
Bronchiectasis refers to abnormal dilatation of the bronchial tree and is seen in a variety of clinical settings. CT is the most accurate modality for diagnosis. It is largely considered irreversible.
As there are many causes of bronchiectasis, which may occur at essentially any a...
Cystic bronchiectasis is one of the less common morphological forms of bronchiectasis. It is characterised by saccular dilatation of bronchi that extend to the pleural surfaces. When aggregated these may give a "bunch of grapes" like appearance. It may be present on its own or may be occur in co...
Thoracic aortic injury is the most common type of traumatic aortic injury and is a critical life-threatening, and often life ending event.
Approximately 80% of patients with thoracic aortic injury die at the scene of the trauma. In those who make it to hospital, clinical...
Aspergillomas are mass-like fungus balls that are typically composed of Aspergillus fumigatus, and are a non-invasive form of pulmonary aspergillosis. It usually falls under the subgroup chronic pulmonary aspergillosis.
Although the term mycetoma is frequently used to describe thes...
Pulmonary manifestations of tuberculosis are varied and depend in part whether the infection is primary or post-primary. The lungs are the most common site of primary infection by tuberculosis and are a major source of spread of the disease and of individual morbidity and mortality.
A general d...
Erdheim-Chester disease (ECD) is a rare non-Langerhans cell, non-familial multisystemic granulomatosis, with widespread manifestations and of highly variable severity. The most common presenting symptom is bone pain.
Erdheim-Chester disease is a rare, non-inherited disease of midd...
Bronchopleural fistula refers to a communication between the pleural space and the bronchial tree.
post-operative complication of pulmonary resection: considered by far the most common cause, with a reported incidence from 1.5 to 28% after pulmonary resection1
Transient tachypnoea of the newborn (TTN), also known as retained fetal fluid or wet lung disease, presents in the neonate as tachypnoea for the first few hours of life, lasting up to one day. The tachypnoea resolves by two days.
amniotic fluid is expressed from the lungs during vag...
Tracheobronchial injury is a serious but uncommon manifestation of chest trauma. It is usually a fatal injury with only a small percentage of patients making it to hospital. Given the magnitude of force required to injure the major airways, there are often multiple chest injuries and other body ...
Tracheal webs occur as a thin layer of tissue that narrows the tracheal lumen. They do not completely obstruct the trachea.
The incidence of congenital tracheal is 1:10,000 births.
Some patients will be asymptomatic. Symptomatic patients can present with a ...
Thymolipoma is a rare, benign anterior mediastinal mass of thymic origin, containing both thymic and mature adipose tissue.
Thymolipomas comprise ~5% (range 2-9%) of all thymic neoplasms, but are less common than a mediastinal lipoma of non-thymic origin. There is no recognised s...
Thymic hyperplasia is a disorder whereby there is hyperplasia of the thymus gland.
Thymus hyperplasia can be subdivided into two forms:
true thymic hyperplasia
Both true thymic hyperplasia and lymphoid hyperplasia manifest as diffuse symmetric enlargement of...
Thymic epithelial tumours are rare tumours arising from thymus in anterior mediastinum of middle age patients. However, they are still the most common primary neoplasm of the thymus and of the anterosuperior mediastinum. This article discusses thymomas, invasive thymomas and thymic carcinoma.
Thymic carcinoma is part of the malignant end of thymic epithelial tumours.
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. ...
Thymic carcinoid tumour refers to a carcinoid tumour arising in the thymus. It is the most common histologic type for a neuroendocrine tumour of the thymus.
Affected patients are typically in the fourth or fifth decades of life. There is a recognised male predominance with M:F ra...
Thoracic myelolipomas are extremely rare entities; only ~3% of myelolipomas are thought to occur in the thorax. When do occur in the thorax they can manifest as
mediastinal myelolipoma: most occur in the posterior mediastinum
intrapulmonary myelolipoma (much less common)
As with my...
Thoracic (or pulmonary) histoplasmosis refers to pulmonary manifestations from infection with the organism Histoplasma capsulatum which is an organism endemic to El Salvador but can be found widely in other parts of North, Central and South America. It can have variable clinical and radiographic...
Thoracic endometriosis is an uncommon location for endometriosis and the main cause of catamenial pneumothorax.
Most often occurs in the third and fourth decades of life 3.
Symptoms may include:
catamenial pleuritic chest pain
catamenial haemoptysis: whe...
Pleural-thoracic empyema (commonly referred simply as an empyema) or pyothorax refers to an infected purulent and often loculated pleural effusion, and is a cause of a large unilateral pleural collection. It is a potentially life-threatening condition requiring prompt diagnosis and treatment.
Thoracic aortic aneurysms are relatively uncommon compared to abdominal aortic aneurysms. There is a wide range of causes, and the ascending aorta is most commonly affected. CTA and MRA are the modalities of choice to image this condition.
The term aneurysm is used when the axial d...
The Macklin effect describes one of the pathophysiological processes of pneumomediastinum in blunt chest trauma. The Macklin effect accounts for ~40% of severe blunt traumatic pneumomediastinum. Exclusion of tracheobronchial and oesophageal causes of pneumomediastinum is mandatory to exclude con...
Thalassaemia is an autosomal recessive haemoglobinopathy that originated in the Mediterranean region. The genetic defect causes a reduction in the rate of globin chain synthesis which causes the formation of abnormal haemoglobin molecules. The resultant microcytic anaemia is the characteristic p...
The posterior wall of bronchus intermedius, also known as the intermediate stem line, is a stripe formed by the interface of the posterior wall of bronchus intermedius and the air within the azygo-oesophageal recess 1.
It normally measures between 0.5-2 mm in thickness but is not considered abn...
Takayasu arteritis (TA), also known as idiopathic medial aortopathy or pulseless disease, is a granulomatous large vessel vasculitis that predominantly affects the aorta and its major branches. It may also affect the pulmonary arteries. The exact cause is not well known but the pathology is thou...
Epipericardial fat necrosis is a rare self-limiting cause of an acute chest pain in an otherwise healthy individuals. It occurs within the mediastinum outside the pericardium.
The patient presents with an acute chest pain that may mimic other cardiopulmonary causes. It is...
Unilateral pulmonary vein atresia is a type of pulmonary vein atresia.
The condition usually present in infancy or childhood with recurrent episodes of pneumonia and/or haemoptysis. Presentation in adulthood does occur but is uncommon.
It results from failure ...
Extrapleural haematomas are uncommon and usually seen in the context of rib fracture, subclavian venous catheter traumatic insertion, and blunt chest injury.
Extrapleural haematomas result from the accumulation of blood in the extrapleural space where the overlying extrapleural fat i...
Tuberculous empyema is a chronic, active infection of the pleural space characterized by thick rind of pleura with thick and irregular calcification of both parietal and visceral pleura usually surrounding a loculated pleural fluid which contains a large number of tubercle bacilli 1.
It is diff...
Tuberculomas or tuberculous granulomas are well defined focal masses that result from Mycobacterium tuberculosis infection and are one of the more severe morphological forms of tuberculosis. Tuberculomas most commonly occur in the brain (see: CNS tuberculosis) and the lung (see: pulmonary tuberc...
Ewing sarcoma family of tumours (ESFT), also referred as Ewing sarcomas of the chest wall, are malignant tumours affecting children and young adults, originating either from the osseous structures or the soft tissues of the chest wall.
On imaging, they are usually characterised as a large extr...
Pulmonary manifestations of Erdheim-Chester disease are uncommon.
The lungs are affected in ~25% (range 20-35%) of cases 5.
Described findings include 1
symmetric reticular interstitial opacities
smooth interlobular septal thickening and fiss...
American Thoracic Society (ATS) criteria for the histopathological diagnosis of usual interstitial pneumonia (UIP) are as follows:
advanced subpleural or paraseptal fibrosis +/- honeycombing
patchy temporally heterogeneous fibrosis
the absence of features against UIP
Epithelial-myoepithelial carcinoma of lung is a very rare type of lung carcinomas of the salivary gland type.
Diagnosis is based on the identification of myoepithelial cells, with spindle cells, clear cells, or plasmacytoid differentiation or a mixture of phenotypes, along with a var...
Usual interstitial pneumonia (UIP) is one of the morphological and pathological patterns of interstitial lung disease.
On imaging, it usually presents with a patchy craniocaudal gradient of peripheral septal thickening, bronchiectasis, and honeycombing.
In the past, the term UIP ...
Upper lobe pulmonary venous diversion (cephalisation) reflects elevation of left atrial pressure and can occur with pulmonary oedema. It produces Stag-antler's sign on frontal chest x-ray.
The normal left atrial pressure is 5-10 mmHg. An elevation of left atrial pressure to 10-15 mmHg will resu...
A tumour-to-tumour metastasis, also known as a collision tumour, is a rare metastatic process in which a primary malignant tumour ('donor') metastasises to another tumour ('recipient'), most commonly a benign tumour such as a meningioma.
Tumour-to-tumour metastasis is considered v...
Empyema necessitans (also sometimes spelt as empyema necessitasis) refers to extension of a pleural infection out of the thorax and into the neighbouring chest wall and surrounding soft tissues, e.g. extension of an empyema outwith the pleural cavity.
It may either occur due the viru...
Kaposi sarcoma is a low-to-intermediate grade mesenchymal tumour that involves the lymphovascular system. The tumour can involve the pulmonary, gastrointestinal, cutaneous and musculoskeletal systems.
There are four recognised variants 1:
classic (chronic): multiple distal lower ext...
Hydatid cysts result from infection by the Echinococcus, and can result in cyst formation anywhere in the body.
There are two main species of the Echinococcus tapeworm 1,2:
pastoral: dog is a main host; most common form
sylvatic: wolf is a main h...
The internal thoracic artery (previously called the internal mammary artery) supplies the anterior body wall and its associated structures from the clavicles to the umbilicus.
The internal thoracic artery arises from the first part of the subclavian artery in the base of...
Hyperimmunoglobulin E (hyper IgE) syndrome (HIES), also known as Job syndrome, consists of a heterogeneous group of complex hereditary combined B- and T-cell immune deficiency diseases characterised by recurrent Staph aureus chest infections, characteristic coarse facial appearance and dental pr...
Horseshoe lung is one of the rare congenital anomalies of the lung. A band of pulmonary parenchyma is formed extending between the right and left lungs. The pulmonary tissue can be seen either anterior to the aorta or posterior to the pericardium at the caudal end.
Pulmonary manifestations of Hodgkin lymphoma are relatively rare, present in 5-12% of patients at the time of diagnosis. It is relatively more common with the nodular sclerosing subtype. Pulmonary involvement usually indicates stage IV disease.
Bilateral involvement is ...
High attenuation lymphadenopathy has been described with:
Kaposi sarcoma 1,6
angioimmunoblastic lymphadenopathy (AILD)
Kimura disease (due to nodal haemorrhage) 6
metastatic hypernephroma (presumed due to nodal haemorrhage) 6
If there is calcification associat...
Heroin-induced pulmonary oedema is an aetiological subtype of non-cardiogenic pulmonary oedema. It may be prevalent in up to 40% of patients admitted with a heroin overdose 2.
It is defined by some authors as a syndrome in which a patient develops significant hypoxia (room air saturation< 90% w...
Hereditary haemorrhagic telangiectasia (HHT), also known as Osler-Weber-Rendu syndrome, is a rare inherited disorder characterised by abnormal blood vessel formation in the skin, mucous membranes, and organs including the lungs, liver, and central nervous system.
Hepatopulmonary syndrome (HPS) refers to the combination of
hepatic dysfunction (cirrhosis)
hypoxaemia (alveolar-arterial O2 gradient of >15mmHg; >20mmHg in >64year old patients).
peripheral pulmonary arterial dilatation (due to right to left micro-shunts).
It is estimated to b...
Pulmonary hepatisation refers to the alteration of lung tissue such that it resembles liver tissue. It is a stage of lobar pneumonic consolidation.
In the early stage, haemorrhagic fluid accumulates within the alveoli and gets organised resulting in a pathological appearance called "...
A hard metal pneumoconiosis is usually classified as a type of fibrotic pneumoconiosis where the precipitating agent consists of a hard metal (not a heavy metal) such as.
tungsten/tungsten carbide alloys
or a mixture
A broader term used is hard metal lung disease (HMLD) w...
Hairy pleural plaques are a manifestation of asbestos-related disease. They arise from the visceral pleura, typically from an interlobar fissure. The hairiness stems from short radially-oriented linear regions of fibrosis extending from the plaque into the adjacent lung parenchyma.
Compared to ...
Haemothorax literally means blood within the chest, is a term usually used to describe a pleural effusion due to accumulation of blood. If a haemothorax occurs concurrently with a pneumothorax it is then termed a haemopneumothorax.
A tension haemothorax refers to haemothorax that results from ...
Haemorrhagic pulmonary metastases are those which tend to be complicated by pulmonary haemorrhage within them, resulting in characteristic imaging appearances. Metastases of some tumour histologies are more likely to haemorrhage -- knowledge of this can help refine the differential diagnoses.
Haemorrhagic pneumonia refers to a descriptive term for pneumonia (infective - inflammatory consolidation of the lung) when is complicated by pulmonary haemorrhage. It can be localised or diffuse to varying degrees dependant on the extent of involvement +/- aetiological agent.
Haemoptysis refers to coughing out blood. Generally, it appears bright red in colour as opposed to blood from gastrointestinal tract which appears dark red. It is considered an alarming sign of a serious underlying aetiology.
Massive haemoptysis is referred to as expectoration of >...
Haemopneumothorax is a term given when there is concurrent presence of a haemothorax and well as a pneumothorax. It is a variant of a hydropneumothorax.
Approximately 5% of patients with pneumothorax will have concomitant haemothorax 6 .
It is typically seen in the se...
Acquired immunodeficiency syndrome (AIDS) is an immunosuppressed state, caused by infection with the human immunodeficiency virus (HIV). It is characterised by opportunistic infections, neoplasms and neurological manifestations.
According to the United Nations programme on HIV/AID...
There are many thoracic complications that can occur following haematopoietic stem cell transplantation. These can precipitate during various stages following transplantation and can be either infectious or noninfectious.
H1N1 influenza is a strain of influenza that notably resulted in a pandemic in 2009.
It is a type of influenza A virus of swine origin.
There can be a wide spectrum of clinical syndromes with patient's ranging from being asymptomatic to having fulminating vira...
The so-called galaxy sign, initially described as the sarcoid galaxy, represents a coalescent granuloma seen in a minority of patients with pulmonary sarcoidosis 1. The same appearance can be seen in tuberculosis 2,3. In other words, it represents a mass-like region composed of numerous smaller ...
Elastofibroma dorsi is a benign soft-tissue tumour with a characteristic location and imaging appearance.
It is more frequently seen in older women, with a reported female predilection of 5-13:1. The estimated mean age at diagnosis around 65-70 years.
Elevated hemidiaphragms can result from many causes:
above the diaphragm 1
decreased lung volume
phrenic nerve palsy
contralateral stroke: usually middle cerebral artery distribut...
Getting a film with left upper lobe collapse in the exam is one of the many exam set-pieces that can be prepared for.
This frontal chest radiograph shows a hazy (or veil-like*) opacification of the left hemithorax that is associated with superior displacement left hilum and horizon...
Left upper lobe collapse has distinctive features but can be challenging to identify on chest radiographs by the uninitiated.
For a general discussion refer to the article on lobar collapse.
The left upper lobe collapses anteriorly becoming a thin sheet...
The azygos vein is a unilateral vessel that ascends in the thorax to the right side of the vertebral column, carrying deoxygenated blood from the posterior chest and abdominal walls. It forms part of the azygos venous system.
The azygos vein is formed by the union of the...
Dysphagia lusoria is an impairment of swallowing due to compression from an aberrant right subclavian artery (arteria lusoria).
Most patients with aberrant right subclavian arteries do not have symptoms. Some present with mild dysphagia, while a small minority have a seve...
Desquamative interstitial pneumonia (DIP) is an interstitial pneumonia closely related to and thought to represent the end stage of respiratory bronchiolitis interstitial lung disease (RB-ILD). It is associated with heavy smoking.
It is considered one of the rarest of idiopathic i...
Folliculin gene-associated syndrome (FLCN-S) or Birt-Hogg-Dubé (BHD) syndrome is a genetic multisystemic disease mainly characterised by:
multiple lung cysts and secondary spontaneous pneumothoraces
multiple bilateral renal tumours (particularly chromophobe renal cell cancer and oncocytoma)
CT guided thoracic biopsy is usually performed for the diagnosis of suspicious lung, pleural or mediastinal lesions. It can be performed as an outpatient where patient monitoring and complications support are available. A small percentage of lung and pleural biopsies may be performed under ultr...
Diffuse panbronchiolitis (DPB) or Asian panbronchiolitis is an idiopathic progressive inflammatory small airway obstructive lung disease.
There is striking predilection in East Asia (e.g. Japan, Korea, China). It tends to present in middle-aged (~ 30-60-year-old) adults, often non...