Articles

Articles are a collaborative effort to provide a single canonical page on all topics relevant to the practice of radiology. As such, articles are written and edited by countless contributing members over a period of time. A global group of dedicated editors oversee accuracy, consulting with expert advisers, and constantly reviewing additions.

1,356 results found
Article

Paralabral cyst of the hip

Paralabral cysts of the hip joint are a location specific subtype of paralabral cysts. They are predominantly small, sometimes septate, well-defined multiloculated fluid intensity lesions seen closely associated with acetabular labral tears. Their presence requires a thorough search for a labral...
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Paralabral cyst of the shoulder

Paralabral cysts of the shoulder are an infrequent finding on MRI, however are an important diagnostic entity as they may cause a compression neuropathy of the suprascapular or axillary nerves depending on where they occur, along with a variety of other symptoms.  Epidemiology They may occur i...
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Paranasal sinuses retention cysts

Retention cysts of paranasal sinuses are benign lesions usually discovered incidentally on a plain sinus radiograph or cross-sectional imaging of the head. They do not usually cause symptoms.  Terminology They are also referred to as mucous retention cysts. Epidemiology It is difficult to es...
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Paranasal sinus mycetoma

Paranasal sinuses mycetoma are indolent and non-invasive fungal colonisation of the paranasal sinuses.   Pathology Pathogenesis is thought to be a cascade of processes from insufficient mucociliary clearance leading to sinus colonisation and chronic inflammatory response. The patient may only ...
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Paranasal sinus osteoma

Osteoma of the paranasal sinuses is a common benign tumour, usually found incidentally. Epidemiology Osteomas are commonly found in patients undergoing imaging of the sinuses, appearing in up to 3% of CT examinations of the paranasal sinuses 1. They are most frequently diagnosed in 20-50 years...
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Paraneoplastic cerebellar degeneration

Paraneoplastic cerebellar degeneration is a type of paraneoplastic syndrome characterised by the progressive onset of cerebellar dysfunction not explained by tumoral invasion, metastasis, or treatment side effects.  Epidemiology It is an uncommon paraneoplastic syndrome that has been reported ...
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Paraneoplastic rhombencephalitis

Paraneoplastic rhombencephalitis corresponds to a perivascular and interstitial inflammatory process affecting the hindbrain (brainstem and cerebellum) associated with a systemic cancer, small cell lung cancer in the majority of cases. Compared with infectious rhombencephalitis, paraneoplastic ...
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Para-oesophageal hernia

Para-oesophageal hernias (POH), or rolling hernias, are an uncommon type of hiatal hernia representing ~10% of all hiatal hernias. The majority of the hiatal hernias being of the sliding type. Clinical presentation Can vary and can include: asymptomatic gastro-oesophageal reflux disease (mai...
Article

Parapharyngeal abscess

Parapharyngeal abscesses are deep neck abscesses involving the parapharyngeal space. It is a serious medical condition, potentially fatal, and requires prompt diagnosis treatment. Epidemiology A person of any age can develop a parapharyngeal abscess, but it is most commonly seen in children an...
Article

Parapneumonic effusion

Parapneumonic effusion (PPE) refers to an exudative pleural effusion associated with pulmonary infection. Epidemiology Approximately 40% of patients who are hospitalised for pneumonia develop a PPE 3. Pathology Fluid leaks into the pleural space due to increased permeability of the visceral ...
Article

Paraseptal emphysema

Paraseptal emphysema refers to a morphological sub type of pulmonary emphysema. Paraseptal emphysema is located adjacent to the pleura and septal lines with a peripheral distribution within the secondary pulmonary lobule. The affected lobules are almost always sub-pleural, and demonstrate small...
Article

Paraspinal ganglioneuroma

Paraspinal ganglioneuromas are extremely rare. Like neuroblastomas and ganglioneuroblastomas, ganglioneuromas are derived from the primordial neural crest cells that form the sympathetic nervous system. Please refer to ganglioneuroma for a more general discussion including epidemiology, clinica...
Article

Parathyroid adenoma

Parathyroid adenomas are benign tumours of the parathyroid glands, and are the most common cause of primary hyperparathyroidism. Clinical presentation Patients present with primary hyperparathyroidism: elevated serum calcium levels and elevated serum parathyroid hormone levels. This results in...
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Parathyroid hormone

Parathyroid hormone (PTH), also known as parathormone, is secreted by the parathyroid glands in response to hypocalcaemia. Its main physiologic effects are to increase osteoclastic activity in bone increase renal reabsorption of calcium inhibit renal absorption of phosphate and bicarbonate s...
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Parathyroid hyperplasia

Parathyroid hyperplasia is the diffuse enlargement of the parathyroid glands and is a less common cause of primary hyperparathyroidism.  Epidemiology There is a female predilection (M:F = 1:3).  Clinical presentation Most commonly an incidental finding of hypercalcaemia in asymptomatic patie...
Article

Paratracheal air cyst

Paratracheal air cysts are not uncommon in routine thoracic imaging. They characteristically occur on the right side. They occur in the region of the thoracic outlet. Epidemiology  They are present in approximately 3-4% of the population. They may be seen in children and adults with an increas...
Article

Parietal foramina

Parietal foramina are a type of congenital calvarial defect. They result from delayed/incomplete ossification of the parietal bone. Pathology They can occur as an isolated autosomal dominant trait or as part of a syndrome. Ossification along a midline bar may separate confluent parietal defect...
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Parkinson disease

Parkinson disease (PD), also known as idiopathic parkinsonism, is a neurodegenerative disease and movement disorder characterised by a resting tremor, rigidity and hypokinesia due to progressive degeneration of dopaminergic neurons in the substancia nigra.  Epidemiology Parkinson disease is by...
Article

Parosteal osteosarcoma

Parosteal osteosarcoma is a subtype of osteosarcoma, and arises from the outer layer of the periosteum.  Epidemiology It is the most common type of juxtacortical or surface osteosarcoma and accounts for ~5% of all osteosarcomas. It typically presents in early adulthood and middle age with a pe...
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Pars peronea metatarsalis primi

Pars peronea metatarsalis primi, also known as pars peronea metatarsalia, is a rare accessory ossicle of the foot, found along the plantar aspect of the base of the first metatarsal, near or at the most distal insertion of the peroneus longus tendon. 
Article

Partial anomalous pulmonary venous return

Partial anomalous pulmonary venous return (PAPVR), also known as partial anomalous pulmonary venous connection (PAPVC), is a rare congenital cardiovascular condition in which some of the pulmonary veins, but not all, drain into the systemic circulation rather than in the left atrium. Clinical p...
Article

Partial hydatidiform mole

Partial hydatidiform mole (PHD) is a sub type of  hydatidiform mole which in turn falls under the spectrum of gestational trophoblastic disease.  Clinical presentation Clinical signs and symptoms such as abdominal pain, cramps of the lower abdomen and vaginal bleeding during pregnancy are non ...
Article

Parturition induced pelvic instability

Parturition-induced pelvic instability is a rare condition seen in women following vaginal delivery.  Epidemiology The incidence of symphyseal rupture after vaginal delivery ranges from one in 600 to one in 30,000 deliveries 1.  Predisposing factors include multiparity, complicated delivery, ...
Article

Parvovirus B19 arthritis

Parvovirus B19 arthritis is one of the most common causes of viral arthritis and characterised as an acute onset symmetrical polyarthritis of small joints of hands and wrist which predominantly involves the carpal, metacarpophalyngeal, and proximal interphalangeal joints. Most common group of pa...
Article

Passive hepatic congestion

Passive hepatic congestion or congested liver in cardiac disease is the stasis of blood in the hepatic parenchyma, due to impaired hepatic venous drainage which leads to widening and splaying of the central hepatic veins and hepatomegaly.  Passive hepatic congestion is a well-studied result of ...
Article

Patellar instability

Patellar instability is the clinical syndrome due to morphologic abnormalities in the patellofemoral joint where the patella is prone to recurrent lateral dislocation. Epidemiology Most patients with patellar instability are young and active individuals, especially females in the 2nd decade. P...
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Patellar tendon lateral femoral condyle friction syndrome

Patellar tendon lateral femoral condyle friction syndrome also known as Hoffa fat pad impingement syndrome is a common cause of anterior knee pain in active individuals. It is thought to be due to patella maltracking or imbalance of the forces between medial and lateral vastus muscles causing im...
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Patent ductus arteriosus

Patent ductus arteriosus or arteriosum (PDA) is a congenital cardiac anomaly where there is persistent patency of the ductus arteriosus, a normal connection of the fetal circulation between the aorta and the pulmonary arterial system that develops from the 6th aortic arch. Epidemiology PDAs oc...
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Pellegrini-Stieda lesion

Pellegrini-Stieda lesions are ossified post-traumatic lesions at (or near) the medial femoral collateral ligament adjacent to the margin of the medial femoral condyle. One presumed mechanism of injury is a Stieda fracture (avulsion injury of the medial collateral ligament at the medial femoral c...
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Pelvic abscess

A pelvic abscess refers to a collection of pus in the pelvis, Pathology  Causes  Some of the causes include pelvic inflammatory disease (tubo-ovarian abscess) post surgical inflammatory bowel disease pelvic actinomycosis infection diverticulitis Clinical presentation Presenting complai...
Article

Pelvic inflammatory disease

Pelvic inflammatory disease (PID) is a broad term that encompasses a spectrum of infection and inflammation of the upper female genital tract, resulting in a range of abnormalities.  Epidemiology The highest incidence is seen among sexually active women in their teens, with 75% cases being und...
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Pelvic insufficiency fracture

Pelvic insufficiency fractures are a relatively common subtype of insufficiency fracture, and are recognised as a major cause of low back, buttock and groin pain in susceptible populations. Clinical presentation Patients most frequently present with a history of minor trauma or an insidious on...
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Pelvic osteotomies

Pelvic osteotomy relates to an orthopaedic treatment for developmental acetabular dysplasia of the hip. The main purpose of pelvic osteotomy is the prevention of early degenerative changes by stabilisation of the hip and redistribution of joint loading. It is obtained by surgical re-shaping/ re...
Article

Pelvi-ureteric junction obstruction

Pelvi-ureteric junction (PUJ) obstruction/stenosis, also known as ureteropelvic junction (UPJ) obstruction/stenosis, can be one of the causes of an obstructive uropathy. It can be congenital or acquired with a congenital PUJ obstruction being one of the commonest causes of antenatal hydronephros...
Article

Penetrating atherosclerotic ulcer

Penetrating atherosclerotic ulcers (PAU) is a pathology that involves the aortic wall and along with aortic dissection and aortic intramural haematoma from the spectrum known as acute aortic syndrome.  Epidemiology Typically, penetrating atherosclerotic ulcers are seen in older male patients w...
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Penetrating thoracic trauma

Penetrating thoracic trauma, namely gunshot and stab injuries, vary widely in incidence globally but nevertheless result in high mortality and serious morbidity. CT is the modality of choice in imaging these patients and can reduce the need for surgical exploration.  Pathology Penetrating thor...
Article

Perianal abscess

Perianal abscess refers to a formed infective-inflammatory collection within the perianal region. It forms part of the broader group of anorectal abscesses. They are often associated with perianal fistulae and are components of grades 2 and 4 fistulae of the St James’ university hospital classif...
Article

Peri-aneurysmal retroperitoneal fibrosis

Peri-aneurysmal retroperitoneal fibrosis is a subtype of a spectrum of retroperitoneal fibrosis. It is characterised by association with an inflammatory aneurysm, adventitial and peri-adventitial inflammation, medial thinning and chronic retroperitoneal inflammatory process which is associated w...
Article

Pericaecal hernia

Pericaecal hernia is a rare type of internal hernia. Epidemiology It accounts for only 6-13% of internal abdominal hernias. Pathology Four subtypes (ileocolic, retrocaecal, ileocaecal, and paracaecal) of herniations occur in the pericaecal fossa (located behind the caecum and ascending colon...
Article

Pericardial agenesis

Pericardial agenesis is a rare condition where there is the absence of the pericardium to varying degrees. If it is only a small portions of the pericardium that is absent it is known as a pericardial defect. Epidemiology According to a surgical and pathological series, the prevalence (inclusi...
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Pericardial effusion

Pericardial effusions occur when excess fluid collects in the pericardial space (a normal pericardial sac contains approximately 30-50 mL of fluid). Epidemiology There is no single demographic affected, as there are many underlying causes of a pericardial effusion. Clinical presentation Clin...
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Pericardial lipoblastoma

Pericardial lipoblastomas are rare benign tumours that usually occur in children less than 3 years of age. The originate from embryonic fat cells and are divided into two forms, based on location 1: superficial form: well circumscribed and well encapsulated deep form: not well circumscribed an...
Article

Pericardial lipoma

Pericardial lipomas are slowly growing benign tumours of the pericardium that are asymptomatic unless large in size, where they can cause pressure symptoms. Radiographic features Echocardiography Tends to be echogenic structure adjacent or inside the pericardium. CT Seen as a fatty attenuat...
Article

Pericardial mesothelioma

Pericardial mesothelioma refers to a mesothelioma arising primarily from the pericardium.  Epidemiology They are rare and are only thought to account for ~ 0.7% of all malignant mesotheliomas. There is male to female predominance of approximately 3:1. Clinical presentation The presentation o...
Article

Perigastric appendagitis

Perigastric appendgitis is a rare inflammatory/ischemic process involving the perigastric ligaments (gastrohepatic, gastrospleic and falciform ligaments). Epiploic appendagitis, greater omental infarction, and perigastric appendgitis have similar mechanisms, clinical presentations, and radiolog...
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Perineal hernia

Perineal hernias are rare pelvic hernias, occurring through a defect in the pelvic floor musculature. Epidemiology More common in females, with peak age of presentation between 40 and 60 years.  Pathology Perineal hernias are classified as anterior or posterior depending on their relationshi...
Article

Perineural spread of tumour

Perineural spread of tumour is a form of local invasion in which primary tumours cells spread along the tissues of the nerve sheath.  It is a well-recognised phenomenon in head and neck cancers. An important distinction has to be made between perineural invasion (PNI) and perineural spread (PNS...
Article

Periosteal osteosarcoma

Periosteal osteosarcoma is a form of surface osteosarcoma.  Epidemiology It is the second most common type of juxtacortical or surface osteosarcoma after parosteal osteosarcoma accounts for 1.5% of all osteosarcoma cases. It affects a slightly older age group (10-20 years) c.f. conventional os...
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Peri-partum/post-partum cardiomyopathy

Peri-partum/post-partum cardiomyopathy is a dilated cardiomyopathy that may occur in the last trimester of pregnancy through the first several months post-partum. Pathology The pathogenesis of post-partum cardiomyopathy is uncertain, with genetic factors, sympathetic tone, hormones, and malnut...
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Peripheral arterial disease

Peripheral arterial disease is a common and debilitating condition. Epidemiology The age-adjusted prevalence of peripheral arterial disease is ~12% 3. Pathology Atherosclerosis is the leading cause of occlusive arterial disease of the extremities in patients over 40 years of age with the hig...
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Peripheral pulmonary carcinoid tumour

Peripheral pulmonary carcinoid tumour refer to a subtype of pulmonary carcinoid tumours that arise within the periphery of the lung. They are considered less common than the more centrally located bronchial carcinoid tumours.  Clinical presentation Many patients tend to be asymptomatic  2. Pre...
Article

Perisplenitis

Perisplenitis is acute inflammation of the splenic capsule and its peritoneal covering. Epidemiology It is seen uncommonly but there is no data on its actual incidence. Clinical Presentation It is seen usually in young and middle-aged patients, with acute left hypochondrial or lower chest pa...
Article

Peritoneal inclusion cyst

Peritoneal inclusion cyst (PIC) (also known as a peritoneal pseudocyst) is a type of cyst-like structure that appears in relation to the peritoneum and results from a non neoplastic reactive mesothelial proliferation. Epidemiology Peritoneal inclusion cysts occur almost exclusively in premenop...
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Peritoneal mesothelioma

Peritoneal mesothelioma is an uncommon primary tumour of the peritoneal lining. It shares epidemiological and pathological features with but is less common than its pleural counterpart, which is described in detail in the general article on mesothelioma. Other sub-types (also discussed separatel...
Article

Peritonsillar abscess

Peritonsillar abscess or quinsy is the most common deep neck infection. Epidemiology Peritonsillar abscesses are most common in 20-40 year olds with a predominance for males and for smokers. It is less common in children but immunosuppression increases the risk of development 2-3. Pathology ...
Article

Perivascular pseudorosettes (ependymoma)

Perivascular pseudorosettes are a common histologic feature of central nervous system ependymomas. They represent sections through papillary structures composed of tumour cells arranged radially around a central vessel. Between the central vessel and the tumour cells is a relatively microscopica...
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Periventricular leukomalacia

Periventricular leukomalacia (PVL) or white matter injury of prematurity affecting the periventricular zones, and typically results in cavitation and periventricular cyst formation.  It is important to note that both periventricular and subcortical leukomalacia correspond to a continuous diseas...
Article

Peroneal tubercle hypertrophy

Peroneal tubercle hypertrophy refers to the presence of an unusually large peroneal tubercle. Radiographic features Two bony projections or protuberances may be seen from the lateral wall of the calcaneus – the peroneal tubercle and the retrotrochlear eminence. The peroneal tubercle is presen...
Article

Persistent right umbilical vein

A persistent right umbilical vein (PRUV) is an uncommon vascular anomaly which is often detected in utero. Epidemiology The estimated prevalence is at ~2 per 1000 births 1-2. Pathology In the normal situation, the right umbilical vein begins to obliterate in the ~4th week of gestation and di...
Article

Perthes disease

Perthes disease (also referred to as Legg-Calvé-Perthes disease) refers to idiopathic osteonecrosis of the femoral epiphysis seen in children. It should not be confused with Perthes lesion of the shoulder. It is a diagnosis of exclusion and other causes of osteonecrosis (including sickle cell d...
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Petersen hernia

Petersen hernias are internal hernias which occur in the potential space posterior to a gastrojejunostomy. This hernia is caused by the herniation of intestinal loops through the defect between the small bowel limbs, the transverse mesocolon and the retroperitoneum, after any type of gastrojejun...
Article

Peyronie disease

Peyronie disease is the most common cause of painful penile induration. Fibrous tissue plaques form within the tunica albuginea, causing painful deformity and shortening of the penis. Though clinical diagnosis is usually accurate, the role of imaging is to evaluate extension of plaques, whether ...
Article

Phenylketonuria

Phenylketonuria (PKU) is an inborn error of metabolism resulting from abnormal metabolism of phenylalanine. If untreated, patients can develop central nervous system impairment.  Epidemiology PKU is inherited as an autosomal recessive disorder with an incidence of 1 in 10,000. It is more commo...
Article

Pheochromocytoma

Pheochromocytomas are an uncommon tumour of the adrenal gland, with characteristic clinical, and to a lesser degree, imaging features. The tumours are said to follow a 10% rule: ~10% are extra-adrenal ~10% are bilateral ~10% are malignant ~10% are found in children ~10% are familial ~10% a...
Article

Phospholipase A2 associated neurodegeneration

Phospholipase A2 associated neurodegeneration (PLAN) is an autosomal recessive form of neurodegeneration with brain iron accumulation (NBIA). Clinical presentation PLA2G6 associated diseases have variable syndromes: classic infantile neuroaxonal dystrophy (INAD) atypical neuroaxonal dystroph...
Article

Phthisis bulbi

Phthisis bulbi, also known as end-stage eye, is an atrophic scarred and disorganised globe that may result from a variety of severe ocular insults.  Pathology The globe is reduced in size (usually < 20 mm) with a thickened/folded posterior sclera. Dystrophic calcification is common, and osseou...
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Phyllodes tumour

Phyllodes tumour, also known as cystosarcoma phyllodes, is a rare fibroepithelial tumour of the breast which has some resemblance to a fibroadenoma. It is typically a large, fast growing mass that forms from the periductal stroma of the breast. Epidemiology Phyllodes tumours account for less t...
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Physeal bar

Physeal bars are interruptions of the normal growth plate cartilage, due to the formation of a bony or fibrous bridge between the epiphysis and metaphysis. Left untreated, physeal bars can cause abnormal bone angulation or limb length discrepancies. Clinical presentation  Physeal bars are not ...
Article

Pick bodies

Pick bodies are intracytoplasmic spherical inclusions found in Pick's disease. They are composed of tau fibrils (thus Pick's disease is a taupathy) arranged in a disorderly array 1. Although tau protein is a major component a number of other protein products are present, including ubiquitin and ...
Article

Pick disease

Pick disease is a neurodegenerative disease, and one of the tauopathies characterised by the accumulation of Pick bodies. Terminology Pick disease is sometimes used synonymously with frontotemporal lobar degeneration, although this is probably unwise, as not all cases which fit clinically into...
Article

Pie in the sky bladder

Pie in the sky bladder refers to the appearance of contrast opacified floating bladder seen high in the pelvis due to a presence of a large pelvic haematoma. This sign should raise concern regarding the possibility of an underlying urethral injury.
Article

Pigmented villonodular synovitis

Pigmented villonodular synovitis (PVNS) is a rare benign proliferative condition affecting synovial membranes of joints, bursae or tendons resulting from possibly neoplastic synovial proliferation with villous and nodular projections and haemosiderin deposition. PVNS is most commonly monoarticul...
Article

Pilomatricoma

A pilomatricoma is an uncommon, benign neoplasm thought to arise from hair cortex cells. It was formerly referred to as pilomatrixoma or calcifying epithelioma of Malherbe. Epidemiology the reported incidence ranges between 1 in 500-2000 they make up 0.12% of cutaneous neoplasms and 20% of al...
Article

Pilomyxoid astrocytoma

Pilomyxoid astrocytomas are an aggressive variant of pilocytic astrocytoma with unique clinical and histopathologic characteristics. Epidemiology Pilomyxoid astrocytomas are usually encountered in young children and infants (mean age of 10 to18 months), however, adults cases have been describe...
Article

Pilonidal sinus

Pilonidal sinuses result from a skin and subcutaneous tissue infection, typically occurring at or near the upper part of the natal cleft of the buttocks. As such is it often also termed an intergluteal pilonidal sinus. While it can also occur at other sites (see location section), this article i...
Article

Pineal apoplexy

Pineal apoplexy is rare and refers to the sudden neurological deterioration following haemorrhage in the pineal region, most commonly into a pineal cyst.  Epidemiology The condition is rare and since it results from bleeding from or into an underlying pineal region mass, no single demog...
Article

Pineal germinoma

Pineal germinomas are the most common tumour of the pineal region accounting for ~50% of all tumours, and the majority (~80%) of intracranial germ cell tumours.  Epidemiology There is a marked male predominance with a M:F of ~13:1. Most patients are 20 years or younger at the time of diagnosis...
Article

Pineal gland metastases

Pineal gland metastases are rare and mostly related to primary carcinomas of the lungs, breast, gastrointestinal tract, and kidneys. They usually occur concomitantly with leptomeningeal metastases.   This article will discuss metastatic lesions affecting only the pineal gland. For other intracr...
Article

Pineal parenchymal tumour with intermediate differentiation

Pineal parenchymal tumours with intermediate differentiation (PPTID) are, as the name suggests, tumours which fall between pineocytoma (well differentiated, WHO grade I) and pineoblastomas (poorly differentiated, WHO grade IV)./ They are considered WHO grade II or III tumours 2. Although these t...
Article

Pituitary adenoma

Pituitary adenomas are primary tumours that occur in the pituitary gland and are one of the most common intracranial neoplasms. Depending on their size they are broadly classified into: pituitary microadenoma: less than 10 mm in size pituitary macroadenoma: greater than 10 mm in size Althoug...
Article

Pituitary carcinoma

Pituitary carcinomas are rare tumours indistinguishable from pituitary adenomas on imaging and defined only by the presence of central nervous system or systemic metastases. Epidemiology The incidence is estimated at less than 0.5% of the pituitary symptomatic tumours 1.  Clinical presentatio...
Article

Pituitary lymphoma

Pituitary lymphoma is very rare, although lymphomatous (or leukaemic) infiltration of the perisellar dura is not infrequently encountered as part of more widespread CNS disease. This article concerns itself with involvement of the pituitary itself rather than the region more broadly. For a gener...
Article

Pituitary macroadenoma

Pituitary macroadenomas are the most common suprasellar mass in adults, and responsible for the majority of transsphenoidal hypophysectomy. They are defined as pituitary adenomas greater than 10 mm in size and are approximately twice as common as pituitary microadenomas.  On imaging they usuall...
Article

Pituitary metastases

Pituitary metastases are rare, and unless a systemic metastatic disease is already apparent, are often preoperatively misdiagnosed as pituitary adenomas.  This article will discuss metastatic lesions affecting only the pituitary gland. For other intracranial metastatic locations, please refer t...
Article

Pituitary microadenoma

Pituitary microadenomas are a minority of all pituitary adenomas, but can pose imaging and management challenges on account of their size and protean clinical presentations.  By definition, a microadenoma is less than 10 mm in size. If the same tumour is greater than 10 mm in size, it is then c...
Article

Placenta accreta

Placenta accreta (PA) is both the general term applied to abnormal placental adherence and also the condition seen at the milder end of the spectrum of abnormal placental adherence. This article focuses on the second, more specific definition. In a placenta accreta, the placental villi extend b...
Article

Placenta fenestrata

Placenta fenestrata is one of the variations in placental morphology, which is characterised by one or more areas of focal placental atrophy lacking villi and covered only by the chorion membrane. 
Article

Placenta increta

Placenta increta is an intermediate level in the spectrum of abnormal placental villous implantation and accounts for ~20% of such cases. The placental villi extend beyond the confines of the endometrium and invades the myometrium.  Epidemiology The estimated incidence is increasing (presumabl...
Article

Placental abruption

Placental abruption refers to a premature separation of the normally implanted placenta after the 20th week of gestation and before the 3rd stage of labour. It is a potentially fatal complication of pregnancy and is a significant cause of third-trimester bleeding / antepartum haemorrhage. Epide...
Article

Placental insufficiency

Placental insufficiency is a term given to a situation where the placenta cannot bring enough oxygen and nutrients to the growing fetus. Clinical presentation Fetuses may present with intra-uterine growth restriction (IUGR) (especially asymmetrical IUGR). Pathology It can be primarily caused...
Article

Placental mesenchymal dysplasia

Placental mesenchymal dysplasia (PMD) is a rare, benign condition that is characterised by enlargement of the placenta with multiple bunch of grape-like vesicles that can resemble a molar pregnancy by ultrasound and gross pathologic examination.  Epidemiology This is an often underdiagnosed an...
Article

Placental septal cyst

A placental septal cyst is a placental cyst typically located in a mid placenta. It forms between the cotyledons of the placenta. The cysts contain gelatinous material and are usually 5-10 mm in diameter. They may be present in 10-20% of placentas from full term uncomplicated pregnancies. See a...
Article

Placental site trophoblastic tumour

Placental site trophoblastic tumour (PSTT) is a rare and one of the least common (~ 0.2% 7) forms of gestational trophoblastic disease (GTD). Epidemiology PSTT typically occurs in women of reproductive age with the average age around 30. It may occur after a normal pregnancy, molar pregnancy o...

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