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.
PPB is encountered in childhood, mostly in the first years of life (90% in th...
Pneumatosis coli is a descriptive sign presenting radiographically as intramural gas limited to the colonic wall.
There are different terminologies in the medical literature, such as pneumatosis intestinalis, pneumatosis coli, and pneumatosis cystoides intestinalis. Pneumatosis in...
Porencephaly is a rare congenital disorder that results in cystic degeneration and encephalomalacia and the formation of porencephalic cysts. The term is used variably among radiologists with its broadest definition being a cleft or cystic cavity within the brain 9, and its more narrow definitio...
Positional plagiocephaly, also known as deformational plagiocephaly, refers to a calvarial deformation that results from external pressure after birth when an infant is consistently placed in the same position for rest and sleep. It can be marked in very premature infants, whose heads become fla...
Posterior fossa astrocytomas, those arising either from the cerebellum or from the brainstem are most frequently seen in children. Approximately 60% of all paediatric astrocytomas are found in the posterior fossa (20% brainstem, 40% cerebellum).
Many types of astrocytoma are found in the poster...
Posterior urethral valves (PUVs), also referred as congenital obstructing posterior urethral membranes (COPUM), are the most common congenital obstructive lesion of the urethra and a common cause of obstructive uropathy in infancy.
Posterior urethral valves are congenital and only...
The Potter sequence is a constellation of findings demonstrated postnatally as a consequence of severe, prolonged oligohydramnios in utero.
It consists of:
pulmonary hypoplasia: often severe and incompatible with life
growth restriction (IUGR)
abnormal facies (Potter f...
A helpful mnemonic to remember the common clinical features of Potter syndrome:
P: pulmonary hypoplasia
T: twisted skin (wrinkly skin)
T: twisted face (Potter facies: low set ears, retrognathia, hypertelorism)
E: extremity deformities (limb deformities: club hands...
Pott puffy tumour refers to a non-neoplastic complication of acute sinusitis. It is characterised by a primarily subgaleal collection, subperiosteal abscess, and osteomyelitis. It is usually related to the frontal sinus but is sometimes secondary to mastoid pathology.
Rarer aetiologies include ...
A Pott shunt is a form of palliative surgery performed in patients with tetralogy of Fallot prior to the ability to repair the defect. It consists of a shunt formed between the descending thoracic aorta and the left pulmonary artery.
This does not relieve the right ventricular outflow obstructi...
Prader-Willi syndrome (PWS) is a rare genetic disorder. It is the most common cause of obesity caused by a genetic syndrome and is primarily characterised by:
sexual infancy: hypogonadism
there usually morbid obesity resulting from hyperphagia is amplified by decre...
Preauricular sinuses are common congenital abnormalities that are typically small blind-ended openings near the ascending limb of the helix. These can be a simple pit or have a sinus tract and/or cystic component.
They are most common in East Asian populations with an incidence of...
Pre-axial polydactyly refers to polydactyly where the additional digit is towards the first digit of the hand (radial side) or foot (medially).
Pre-axial polydactyly is less common than post-axial polydactyly, with an estimated incidence of 1 in 7000.
Premature closure of a growth plate subsequently results in a shortened bone, which can occur in a number of situations.
juvenile chronic arthritis
juvenile rheumatoid arthritis
Prenatal onset infantile cortical hyperostosis is a rare variant of infantile cortical hyperostosis; however, it is a more severe and lethal form and newborns die early postnatally.
Both sporadic and autosomal recessive inheritance have been suggested.
A missense mutation in gene (C...
Primary ciliary dyskinesia, also known as immotile cilia syndrome, is the result of a congenital defect in the ultrastructure of cilia that renders them incapable of normal movement. It is associated with a number of anatomic and functional abnormalities.
Primary ciliary dyskinesi...
Primitive neuroectodermal tumours (or CNS PNET) were considered aggressive neoplasms of the brain, most frequently encountered in the paediatric population. Importantly, the term no longer appears in the current WHO classification of CNS tumours 11-12.
Please refer to embryonal tumours with mu...
Propionic acidaemia is a rare organic acidaemia caused by a deficiency in the enzyme propionyl coenzyme A carboxylase.
Propionic acidaemia has an incidence of around 1 in 150,000 in the general population 1.
Around 80% of children with propionic acidaemi...
Proteus syndrome is a rare congenital, multisystemic, hamartomatous condition characterised by asymmetrical overgrowth of almost any part of the body and a broad spectrum of manifestations. It can affect tissue from any germinal layer. It is suspected to be a genetic condition, but a particular ...
Proximal femoral focal deficiency is a congenital partial absence of the proximal end of the femur with shortening of the entire lower limb. The diagnosis and classification have been based mainly on plain radiograph findings. This method does not permit definite classification during the first ...
A proximal radio-ulnar synostosis is an upper limb skeletal malformation characterised by bony fusion at the proximal aspect of the radius and ulna. Of the radio-ulnar synostoses, the proximal third is considered the most common site.
It is often congenital but can rarely result fol...
Prune belly syndrome, also known as Eagle Barrett syndrome 3 or triad syndrome, is a rare anomaly comprising a specific constellation of features. It consists of three major findings:
gross ureteric dilatation
anterior abdominal wall underdevelopment (resulting in the "prune belly" appearance)...
A pseudocyst is an abnormal fluid-filled cavity which is not lined by epithelium. It is this fact that distinguishes it pathologically from a cyst, which is lined by epithelium.
Examples of pseudocysts are:
pseudocysts of the germinal matrix
Pseudocysts of the germinal matrix can be present at birth in both pre-term and full-term infants and may be due to a variety of pathologic disorders, frequently occur following haemorrhage, but they are also found incidentally in otherwise normal infants.
They are defined as pseudocysts becaus...
Pseudosubluxation of the cervical spine is the physiological anterior displacement of C2 on C3 in children. It is common in children <7 years, and less often present in older children. Less often it is seen at C3 on C4. It is more pronounced in flexion and is of clinical significance as it can b...
Pulled elbow (also known as nursemaid's elbow) is a subluxation of the radial head into the annular ligament, which usually spontaneously or easily reduces and rarely demonstrates abnormal radiographic features. It should be distinguished from dislocation of the radial head.
Pulmonary aplasia is a rare congenital pathology in which there is unilateral or bilateral absence of lung tissue. It is distinguished from pulmonary agenesis, although similar, the main difference being that there is a short-blind ending bronchus in aplasia 3.
It is usually unilateral, as bila...
Pulmonary artery atresia (or sometimes known as pulmonary atresia) is a congenital cardiovascular anomaly in which there is complete disruption between the right ventricular outflow tract (RVOT) and the pulmonary trunk.
The estimated incidence is 1 in 10,000 births.
Pulmonary atresia with intact interventricular septum (PA-IVS) is a subtype of pulmonary atresia that presents as cyanotic congenital heart disease.
PA-IVS is the combination of obstruction of the pulmonary outflow tract from pulmonary valve atresia without a ventricular septal defe...
Pulmonary hypoplasia (PH) refers to deficient or incomplete development of parts of the lung. It can develop as a result of a number of other in utero anomalies.
The true prevalence is not well known (1.4% of all births according to Knox et al. 13), but in cases of premature ruptu...
Pulmonary interstitial emphysema (PIE) refers to the abnormal location of air within the pulmonary interstitium and lymphatics. It typically results from rupture of overdistended alveoli following barotrauma in infants who have hyaline membrane disease. Interstitial emphysema can also occasional...
Pulmonary lymphangiectasia (PL) refers to a rare, fatal congenital abnormality of the lungs characterised by grossly dilated lymphatic channels in the sub pleural, interlobar, perivascular and peribronchial areas 3.
It is divided into two main types 1:
cardiac-associated lymphangiectasia (seco...
Pulmonary plethora is a term used to describe the appearances of increased pulmonary perfusion on chest radiographs. It is commonly used in paediatric radiology.
Usually a left-to-right shunt of 2:1 is required for pulmonary plethora to occur 2,3. Increased pulmonary perfusion occur...
Pulmonary sequestration, also called accessory lung, refers to the aberrant formation of segmental lung tissue that has no connection with the bronchial tree or pulmonary arteries. It is a bronchopulmonary foregut malformation (BPFM).
There are two types:
intralobar sequestration (ILS)
Extralobar pulmonary sequestration (ELS) is a subtype of pulmonary sequestration, the other type being intralobar pulmonary sequestration (ILS).
It is usually encountered in infants, most being diagnosed before six months. It is more common in male (M:F 4:1).
Intralobar pulmonary sequestration (ILS) is a subtype of pulmonary sequestration.
Patients usually present before the third decade with recurrent infection.
It is the commoner type of pulmonary sequestration (four times commoner than extralobar sequestration),...
Pulmonary valve stenosis, or pulmonic valve stenosis, is a valvulopathy that describes narrowing of the opening of the pulmonary valve between the pulmonary trunk and the right ventricle.
Pulmonary stenosis is nearly always (95%) congenital, and therefore primarily affects the pae...
Pyknodysostosis, also known as osteopetrosis acro-osteolytica or Toulouse-Lautrec syndrome, is a rare autosomal recessive bone dysplasia, characterised by osteosclerosis and short stature.
Patients present in early childhood with:
short stature, particularly limbs
Hypertrophic pyloric stenosis (HPS) refers to the idiopathic thickening of gastric pyloric musculature which then results in progressive gastric outlet obstruction.
Pyloric stenosis is relatively common, with an incidence of approximately 2-5 per 1,000 births, and has a male pred...
Rachipagus twins are extremely rare type of conjoined twins. They are joined in the dorsal aspect and face away from each other.
Fusion of the occiput with varying segments of the vertebral column may occur, resulting in the sharing of the spinal cords. The fusion terminates above the sacrum. F...
Rachitic rosary refers to expansion of the anterior rib ends at the costochondral junctions and is most frequently seen in rickets as nodularity at the costochondral junctions.
Other causes of this appearance include:
the costochondral junction is more angula...
Radial head dislocation occurs when the radial head is displaced from its normal articulation with the ulna and the humerus.
The dislocation may be acquired or congenital (see the separate article on congenital radial head dislocation). Additionally, radial head dislocation should be distinguis...
Radial ray anomalies comprise of a large spectrum of upper limb anomalies which range from partial (radial hypoplasia) to a complete (radial aplasia) deficiency of the radius with or without accompanying deficiency of the thumb bones.
They can be associated with a numbe...
The radiocapitellar line is one of the key lines used to assess alignment on the elbow radiograph. It is particularly useful in the paediatric setting.
A line drawn down the neck of the radius should intersect the capitellum. It is important to ensure that you draw the line down the r...
Raghib syndrome is a rare developmental complex. It consists of:
persistence of the left superior vena cava
coronary sinus ostial atresia
atrial septal defect
It has also been associated with other congenital malformations including ventricular septal defects, enlargement of the tricuspid an...
Raine syndrome, also known as lethal osteosclerotic bone dysplasia, is a very rare genetic disorder. Infants with this syndrome present with numerous characteristic craniofacial features as well as cerebral calcifications. Many individuals with this disorder are stillborn or die as neonates 4.
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.
As a group, RASopathies represent one of the most common malformation syndromes, with an in...
The rectosigmoid ratio is a measurement of the diameter of the rectum divided by that of the sigmoid colon during contrast enema. It is of particular use in the diagnosis of Hirschsprung disease.
Normal children have a rectum that is larger than the sigmoid (i.e. rectosigmoid ratio >1). In fact...
Renal agenesis refers to a congenital absence of one or both kidneys. If bilateral (traditionally known as the classic Potter syndrome) the condition is fatal, whereas if unilateral, patients can have a normal life expectancy.
Unilateral renal agenesis affects approximately 1 in ...
Renal replacement therapy (RRT) (also called renal dialysis or just dialysis) is used to supplement renal function in patients with either end-stage chronic kidney disease or medically-refractory acute renal impairment.
Haemodialysis refers to the diffusion of solutes in solution across...
Renal tumours (for the purposes of this article taken to broadly mean neoplastic lesions) should be distinguished from renal pseudotumours.
Whilst renal tumours can be broadly divided into primary and secondary (metastatic), benign and malignant or adult and paediatric tumours, they are more fo...
Respiratory distress syndrome (RDS) is a relatively common condition resulting from insufficient production of surfactant that occurs in preterm neonates.
On imaging, the condition generally presents as bilateral and relatively symmetric diffuse ground glass lungs with low volumes and a bell-s...
Retinoblastomas are the most common intraocular neoplasm found in childhood, and with modern treatment modalities are, in most cases, curable.
On imaging, they are generally characterised by a heterogeneous retinal mass with calcifications, necrotic components, and increased vascularisation on ...
Retinopathy of prematurity (ROP) (formerly referred to as retrolental fibroplasia) is an ocular condition seen in the infant population. It often occurs bilaterally, although usually with significant asymmetry 1.
There is often a history of premature delivery, low birth weight, a...
Rhabdoid tumour of the kidney is a rare, highly aggressive malignancy of early childhood, closely related to atypical teratoid/rhabdoid tumours (AT/RT) of the brain (see rhabdoid tumours)
Rhabdoid tumours occur exclusively in children, with 60% occurring before the age of 1 year o...
Rhabdoid tumours are rare and extremely aggressive tumours of early childhood. They occur in a number of locations:
kidney: see malignant rhabdoid tumour of the kidney, most common
intracranial: see atypical teratoid/rhabdoid tumour (AT/RT)
soft tissues, including:
Rhabdomyosarcoma is a malignant tumour with skeletal muscle cell morphology. It is one of the tumours of muscular origin.
This article focuses on a general discussion of rhabdomyosarcomas. For location specific details, please refer to:
rhabdomyosarcomas of the biliary 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.
The peak incidence of ...
Rhabdomyosarcomas of the orbit account for approximately 10-20% of all rhabdomyosarcomas and are usually found in children.
As with other locations, rhabdomyosarcomas in the orbit are overrepresented in males, and in Caucasians. They typically occur in children below the age of 1...
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.
Rhabdomyosarcomas of the head and neck represent a large proportion (~40%) of all rhabdomyosarcomas. For a general discussion of this tumour, please refer to rhabdomyosarcoma.
There are usually of the embryonal in cell subtype and are essentially only seen in children. They are classified by lo...
Rheumatic fever is an illness caused by an immunological reaction following group A streptococcal infection.
Rheumatic fever is most common in children aged 5 to 15 years. It is most common in developing nations where antibiotic prescription is low 1.
Rhombencephalosynapsis (RS) is a congenital abnormality of the cerebellum characterised by the vermis absence and continuity of the cerebellar hemispheres, dentate nuclei, and superior cerebellar peduncles. It either occurs as an isolated anomaly (rare) or as part of wider cerebral malformation ...
Rickets, less commonly known as rachitis, essentially refers to osteomalacia in the paediatric population that occurs before fusion of the growth plate.
Rickets is seen in a number of distinct populations which include 4:
premature infants (especially if on parenteral nutrition)
Right middle lobe syndrome refers to chronic right middle lobe collapse, without an obstructing lesion, and usually with associated bronchiectasis.
Right middle lobe syndrome is usually encountered in older adults, with a predilection for women (see Lady Windermere syndrome). It ...
Ritscher-Schinzel syndrome (RTSC), also known as 3C (cranio-cerebello-cardiac) syndrome, is a rare entity with a variable spectrum of CNS (primarily cerebellar), craniofacial, and congenital heart defects.
Roberts syndrome, also known as Roberts-SC phocomelia syndrome, pseudothalidomide syndrome, or Appelt-Gerken-Lenz syndrome, is a rare congenital malformation syndrome.
intrauterine growth restriction
postnatal growth retardation
failure to thrive
Robin sequence, also called Pierre Robin syndrome or Pierre Robin anamaloid, is a congenital condition characterised by facial abnormalities. Its aetiology has no genetic base, but rather, is reliant on a sequence of events, one following the other.
Robin sequence is the preferred ...
Round pneumonia is a type of pneumonia usually only seen in paediatric patients. They are well defined, rounded opacities that represent regions of infected consolidation.
The mean age of patients with round pneumonia is 5 years and 90% of patients who present with round pneumonia...
Sacral agenesis (also considered as part of the caudal regression syndrome) is a rare and severe sacral developmental abnormality.
In normal pregnancy, the incidence is between 0.005 and 0.1%. However, in fetuses with diabetic mothers, the incidence rises to 0.2%. Of those with th...
Sacral dimples are a clinical and radiological feature that is associated with occult spinal dysraphism (e.g. tethered cord syndrome) but are more frequently a non-significant isolated finding.
Common in healthy children (~5%) 1.
Simple sacral dimples have the followin...
Sacrococcygeal teratoma (SCT) refers to a teratoma arising in the sacrococcygeal region. The coccyx is almost always involved 6.
It is the commonest congenital tumour in the fetus 11 and neonate 3. The incidence is estimated at ~1:35000-40000. There is recognised female predilecti...
The Sakati-Nyhan syndrome, also known as Sakati-Nyhan-Tisdale syndrome or acrocephalosyndactly type III, is an extremely rare type of acrocephalopolysyndactyly.
Its main features include:
congenital limb abnormalities
congenital heart defects
History and etymology
Salla disease, also known as Finnish type sialuria, is a rare autosomal recessive disease that primarily affects the central nervous system. It is considered the mildest form of free sialic acid storage disorder.
Neurological symptoms related to this rare disease are usua...
The Salter-Harris classification was proposed by Salter and Harris in 1963 1 and at the time of writing (June 2016) remains the most widely used system for describing physeal fractures.
Conveniently the Salter-Harris types can be remembered by the mnemonic SALTR.
Useful mnemonics for remembering the Salter-Harris classification system are:
Fortunately, this is also the order of prognosis (from best to worse)
S: slipped (type I)
A: above (type II)
L: lower (type III)
T: through or transverse or together (type IV)
Salter-Harris type I fractures are relatively uncommon injuries that occur in children. Salter-Harris fractures are injuries where a fracture of the metaphysis or epiphysis extends through the physis. Not all fractures that extend to the growth plate are Salter-Harris fractures.
Salter-Harris type II fractures are the most common type of physeal fractures that occur in children. There is a fracture that extends through the physis and into a portion of the metaphysis. A triangular metaphyseal fragment, otherwise known as the Thurston Holland fragment, will be left intact...
Salter-Harris type III fractures are an uncommon, intraarticular fracture physeal fractures that occur in children.
The fracture line is often obliquely orientated through the epiphysis to the physis where it will take a horizontal orientation extending to the edge of the physis.
Salter-Thompson classification for Legg-Calve-Perthes disease simplifies the Catterall classification into 2 groups. Based on the radiographic crescent sign, we can distinguish:
group a: including Catteral groups I and II, where the crescent sign involves less than 50% of the femoral head.
A scalp haematoma usually occurs following an injury at delivery although they are commonly seen with head trauma.
There are three types of haematoma, which are defined by their location within the scalp, particular their location as related to the galea aponeurosis and skull pe...
Scaphocephaly (also known as dolichocephaly) is the most common form of craniosynostosis, where premature closure of the sagittal suture results in impediment to lateral growth of the skull while anteroposterior growth continues, producing a narrow elongated skull. Causes are primary, or seconda...
The Scham sign of slipped capital femoral epiphysis is one of the subtle signs that may be seen on the AP view of an adolescent hip with early slip.
In the normal adolescent hip, an intraarticular portion of the diaphysis of the collum overlies the posterior wall of the acetabulum inferiomedial...
Schizencephaly is a rare cortical malformation that manifests as a grey matter lined cleft extending from the ependyma to the pia mater.
Some authors do not use the term schizencephaly, preferring to group these disorders under the blanket term of porencephaly. For the purpose of t...
Scimitar syndrome, also known as hypogenetic lung syndrome, is characterised by a hypoplastic lung that is drained by an anomalous vein into the systemic venous system. It is a type of partial anomalous pulmonary venous return and is one of the several findings in congenital pulmonary venolobar ...
Sclerosing bone dysplasias comprise a heterogeneous group of disorders (skeletal dysplasias) united by the presence of sclerosis of one form or another. Some of these entities are thought to be related (e.g. osteopoikilosis, melorheostosis and Buschke-Ollendorff syndrome) 1.
Scoliosis is defined as an abnormal lateral curvature of the spine. It is quite common in young individuals and is often idiopathic and asymptomatic. In some cases, however, it is the result of underlying structural or neurological abnormalities.
By definition, a scoliosis is any lateral spina...
The Senning repair is one of two "atrial switch" procedures used to functionally correct transposition of the great arteries (the other being the Mustard repair).
The two repairs share a similar fundamental principle. Systemic blood flow is redirected away from the right ventricle and toward t...
Septo-optic dysplasia (SOD), also known as de Morsier syndrome, is a condition characterised by optic nerve hypoplasia and absence of septum pellucidum and, in two-thirds of patients hypothalamic-pituitary dysfunction. It is best thought of as being part of the holoprosencephaly spectrum (see cl...
Sexual differentiation refers to the embryological development of male and female phenotypes. Unlike sexual genotype which is determined at the time of fertilisation, the male and female phenotypes do not begin to differentiate substantially until the seventh week of gestation.
Shone syndrome, also known as Shone complex, is a rare syndrome characterised by left-sided, obstructive congenital heart defects.
Shone syndrome is thought to be very rare, accounting for less than 1% of all congenital heart disease 1.
Patients, usually ne...
Short limb skeletal dysplasias are skeletal dysplasias which are charcaterised by limb shortening
Rhizomelic (proximal limb shortening)
particularly type II
SHORT syndrome refers to an acronym which primarily comprises of the following features:
S: short stature
H: hyperextensibility of joints and/or inguinal hernia
O: ocular depression
R: Rieger anomaly
T: teething delay
In a addition to these there can be numerous associated minor features w...