A teratoma is a tumour containing tissue elements that are similar to normal derivatives of more than one germ layer. They usually contain skin, hair, teeth and bone tissue and are more common in children, behaving as a benign tumour. After puberty, they are regarded as malignant and can metastasise.

Mongolian spots are, hyper-pigmented, non-blanching patches present on the back and gluteal region at birth. They are commonly found in African and Asian ethnic groups, and can also present in infants of Mediterranean and middle eastern descent. Though the spots usually disappear by puberty, some may persist into adulthood.

From the midgut derives most of the small intestine as well as some parts of the large intestine, including the appendix. The appendix is at the base of caecum, up to 10cm long and mainly comprised of lymphoid tissue (Hence mesenteric adenitis may mimic appendicitis).

Epiglottitis is characterized by the abrupt onset of severe symptoms. Without airway control and medical management, symptoms may rapidly progress to respiratory obstruction and death in a matter of hours.Usually, no prodromal symptoms occur in children. Fever is usually the first symptom, and temperatures often reach 40°C. Acute epiglottitis may result in sudden, complete upper airway obstruction. Classic signs in children are four D’s: drooling, dyspnoea, dysphagia, and dysphonia.

Effective treatment can cure gonorrhoea and help prevent long-term complications. CDC recommends a single dose of 250mg of intramuscular ceftriaxone AND 1g of oral azithromycin. It is important to take all of the medication prescribed to cure gonorrhoea.

The commonest time for bacterial meningitis is in the 1st month of life and group B Streptococcus is the commonest organism. The anterior fontanelle is full, but does not bulge with normal flexion. Neurological manifestations include seizures, irritability, poor tone, lethargy and tremors, however no findings of sensorineural deafness have been noted. One of the risk factors for introduction of meningeal infection is Meningomyelocele.

Based on the history and clinical presentation, she most likely has iron toxicity.Iron can cause scarring of the gut mucosa. This explains her pyloric stenosis. This typically occurs at the pylorus as this is where iron tablets tend to pool and cause maximal tissue damage.Other options:- Citalopram: Selective serotonin reuptake inhibitors (SSRIs) ingestion rarely causes serious consequences. It can rarely lead to serotonin syndrome (autonomic instability, mental status change, and increased neuromuscular tone).- Ibuprofen: While it may cause gastritis, ibuprofen does not cause pyloric/intestinal stenosis.- Thyroxine: An overdose of thyroxine will cause features of hyperthyroidism which are not present in the patient in question.- Zinc: High doses of zinc can cause abdominal cramps, nausea, vomiting and diarrhoea.

To quantify differences between percentages you can use Fisher’s exact test.Odds ratios, relative risks and number needed to treat are ways of quantifying differences between percentages in two groups, however are not in themselves significance tests.

The development of the kidney proceeds through a series of successive phases, each marked by the development of a more advanced kidney: the pronephros, mesonephros, and metanephros. The development of the pronephric duct proceeds in a cranial-to-caudal direction. As it elongates caudally, the pronephric duct induces nearby intermediate mesoderm in the thoracolumbar area to become epithelial tubules called mesonephric tubules. Each mesonephric tubule receives a blood supply from a branch of the aorta, ending in a capillary tuft analogous to the glomerulus of the definitive nephron. The mesonephric tubule forms a capsule around the capillary tuft, allowing for filtration of blood. This filtrate flows through the mesonephric tubule and is drained into the continuation of the pronephric duct, now called the mesonephric duct or Wolffian duct. The nephrotomes of the pronephros degenerate while the mesonephric duct extends towards the most caudal end of the embryo, ultimately attaching to the cloaca.

The umbilical cord that connects the fetus to the placenta is about 50cm long. This tissue consists of the body stalk and vitelline duct. The former containing the allantoic diverticulum and the umbilical vessels. The latter contains the connection linking the digestive tube and the yolk sac. This cord is wrapped by stratum of ectoderm and gelatinous tissue or jelly of Wharton. The right umbilical vein plus the vitelline vessels and ducts disappear and this at birth the cord has three vessels which are the umbilical vein and two umbilical arteries.

Cranial nerves I, II, and VIII are considered purely afferent nerves since they conduct sensory information from the olfactory region, the retina of the eye, and the inner ear structures, respectively.Cranial nerves III, IV, VI, XI, and XII are considered purely efferent due to their motor output to the orbit, the neck, and the tongue.Cranial nerves V, VII, IX, and X are considered mixed cranial nerves due to the presence of afferent and efferent fibres with both sensory and motor components.

Damage to the left parietal lobe can result in what is called Gerstmann’s Syndrome. It includes right-left confusion, difficulty with writing (agraphia) and difficulty with mathematics (acalculia). It can also produce disorders of language (aphasia) and the inability to perceive objects normally (agnosia).Damage to the right parietal lobe can result in neglecting part of the body or space (contralateral neglect), which can impair many self-care skills such as dressing and washing. Right side damage can also cause difficulty in making things (constructional apraxia), denial of deficits (anosognosia) and drawing ability.Bi-lateral damage (large lesions to both sides) can cause Balint’s Syndrome, a visual attention and motor syndrome. This is characterized by the inability to voluntarily control the gaze (ocular apraxia), inability to integrate components of a visual scene (simultanagnosia), and the inability to accurately reach for an object with visual guidance (optic ataxia)Special deficits (primarily to memory and personality) can occur if there is damage to the area between the parietal and temporal lobes.Left parietal-temporal lesions can affect verbal memory and the ability to recall strings of digits. The right parietal-temporal lobe is concerned with non-verbal memory.Right parietal-temporal lesions can produce significant changes in personality.

Pyloric stenosis affects infants, typically in the second to fourth weeks of life and is caused most commonly by hypertrophy and thickening of the pylorus. It usually presents with projectile vomiting and failure to thrive. The infant usually has a normal appetite. Features include: ‘projectile’ vomiting, typically 30 minutes after a feed, constipation and dehydration may also be present and a palpable mass may be present in the upper abdomen.

Coxsackie viruses are a group of RNA viruses with over 20 serotypes| depending on specific viral characteristics, these serotypes are further divided into groups A and B. Infection is associated with a wide range of symptoms, which are dependent on the exact serotype. Hand, foot, and mouth disease (HFMD) and herpangina are commonly caused by group A coxsackie viruses, while pleurodynia and myocarditis are caused by group B coxsackie viruses. Both groups may cause viral meningitis, conjunctivitis, or flu‑like symptoms. Diagnostic procedures and treatment should be tailored to the specific disease manifestation. Coxsackie A :HerpanginaHand, foot, and mouth diseaseCharacteristics: highly contagiousClinical presentationGeneral symptoms: fever, reduced general conditionSkin/mucosaMaculopapular and partially vesicular rash on the hands and feetOral ulcersDiagnosis: clinicalTreatment: symptomaticPrognosis: almost always self‑limiting

Cardiac notch: is an indentation on the left lung of the heart.
Coronary sinus: a venous sinus on the surface of the heart (the posterior aspect) that receives blood from the smaller veins that drain the heart.
Coronary sulcus: a groove on the heart between the atria and ventricles.
Transverse pericardial sinus: located behind the aorta and pulmonary trunk and anterior to the superior vena cava.
Oblique pericardial sinus: located behind the left atrium. Accessed from the inferior side (or the apex) of the heart upwards.
Horizontal pericardial sinus: this is a made-up term.

The combination of cholestasis, congenital heart disease (mainly affecting the pulmonary vasculature) and anterior-segment abnormalities (primarily posterior embryotoxon) suggests a diagnosis of Alagille syndrome. Clinical features:The facial features are characteristic and include a prominent forehead, deep-set eyes and a pointed chin. The most common skeletal manifestation is butterfly vertebrae, a clefting abnormality of the vertebrae most often seen in the thoracic spine and described in up to 87% of cases. Radio-ulnar synostosis and short phalanges have also been described in Alagille but less frequently. Note: Pectus excavatum is a feature of Noonan syndrome, one of the differential diagnoses of pulmonary valve disease.

The characteristic cells in granulomatous inflammation are giant cells, formed from merging macrophages and epithelioid cells elongated with granular eosinophilic cytoplasm. Granulomatous reactions are seen in patients with tuberculosis. A tuberculous/caseating granuloma is characterised by a zone of central necrosis lined with giant multinucleated giant cells (Langhans cells) and surrounded by epithelioid cells, lymphocytes and fibroblasts. The caseous zone is present due to the damaged and dead giant cells and epithelioid cells.
Mast cells are only few in number and fibroblasts lay down collagen.
Basophils are not present.
The giant cell made up of macrophages are the most abundant cells in this inflammatory process.

The drainage of cerebral spinal fluid from the third ventricle to the fourth ventricle is carried out by the cerebral aqueduct. The cerebral aqueduct is the narrowest passageway in the entire ventricular system and thus forms the most common site of blockage of flow of cerebrospinal fluid. The interventricular foramen allows passage of CSF to the third ventricle. The foramen of Luschka and Magendie are located on the fourth ventricle and allow passage of CSF to the subarachnoid space from the ventricular system. The pontine cistern is a space located on the ventral aspect of the pons. The cisterna magna is an opening on the subarachnoid space between the pia matter and the arachnoid.

Infection of chickenpox in the first half of pregnancy can result in congenital varicella syndrome. It presents as cerebral, cortical and cerebellar hypoplasia with convulsions and rudimentary digits. Prevention is by administering varicella vaccine, even before pregnancy. Varicella immunoglobulin is administered to pregnant women who are exposed to infection. Infection during pregnancy is treated with acyclovir.

Liddle’s syndrome,  is an autosomal dominant disorder, that is characterized by early, and frequently severe, high blood pressure associated with low plasma renin activity, metabolic alkalosis, low blood potassium, and normal to low levels of aldosterone. Liddle syndrome involves abnormal kidney function, with excess reabsorption of sodium and loss of potassium from the renal tubule. Bartter Syndrome also presents with hypokalaemia, however blood pressure of these patients is usually low or normal.

At the age of 6 months, children can begin to be weaned off breastmilk and formula feeds. One healthy and inexpensive way to do this is through infant led weaning as opposed to the conventional spoon feeding method. Children are able to enjoy a variety of soft finger foods even before they grow teeth, so all food does not need to be pureed or sweet. Children should however not be given cow’s milk until the age of 1 year.

Treating persons infected with C. trachomatis prevents adverse reproductive health complications and continued sexual transmission, and treating their sex partners can prevent reinfection and infection of other partners. Treating pregnant women usually prevents transmission of C. trachomatis to neonates during birth. Chlamydia treatment should be provided promptly for all persons testing positive for infection. Treatment delays have been associated with complications (e.g. PID) in a limited proportion of women. To minimise disease transmission to sex partners, persons treated for chlamydia should be instructed to abstain from sexual intercourse for 7 days after single-dose therapy or until completion of a 7-day regimen and resolution of symptoms if present. To minimise risk for reinfection, patients also should be instructed to abstain from sexual intercourse until all of their sex partners are treated. Persons who receive a diagnosis of chlamydia should be tested for HIV, GC, and syphilis.

Lung buds are formed by 4-5 weeks of gestation.Development of the respiratory tract has five stages:- Embryonic (at 4 – 5 weeks of gestation):Formation of lung buds, trachea and mainstem bronchi occur. These structures are formed from a ventral outpouching of foregut pharynx. At this stage, the beginnings of the five lung lobes are present.- Pseudoglandular (at 5 – 16 weeks of gestation):Formation of terminal bronchioles, cartilage and smooth muscles occur in this stage. Adult numbers of airways proximal to acini are in place.- Canalicular (at 16-24 weeks gestation): Differentiation of type I and II epithelial cells can be done in this stage. There is also an increase in the size of proximal airways).- Saccular (at 24 – 40 weeks of gestation): Terminal saccule formation occurs. Production of surfactant takes place at this stage with an increase in the number of goblet cellsUp to half the adult number of alveoli are in place by this stage.- Alveolar (occurs between 32 weeks of gestation till the post-natal age 8): Formation of alveoli and septation occurs with the expansion of air spaces.

The likely diagnosis in this case is Haemolytic Uremic Syndrome (HUS), which is generally seen in young children presenting with a triad of symptoms, namely: acute renal failure, microangiopathic haemolytic anaemia, and thrombocytopenia. The typical cause of HUS is ingestion of a strain of Escherichia coli.

Haemophilia B (also known as Christmas disease) is due to a deficiency in factor IX. Haemophilia A is due to a deficiency in factor VIII.

Developmental milestones at 4 months of age:Social and Emotional:Smiles spontaneously, especially at people Likes to play with people and might cry when playing stops Copies some movements and facial expressions, like smiling or frowningLanguage/CommunicationBegins to babble Babbles with expression and copies sounds he hears Cries in different ways to show hunger, pain, or being tiredCognitive (learning, thinking, problem-solving)Lets you know if he is happy or sad Responds to affectionReaches for a toy with one hand Uses hands and eyes together, such as seeing a toy and reaching for it Follows moving things with eyes from side to side Watches faces closely Recognizes familiar people and things at a distance Movement/Physical DevelopmentHolds head steady, unsupported Pushes down on legs when feet are on a hard surface May be able to roll over from tummy to back Can hold a toy and shake it and swing at dangling toys Brings hands to mouth When lying on stomach, pushes up to elbows

In the prenatal heart, right-to-left atrial shunting of blood through the foramen ovale is essential for proper circulation. After birth, as the pulmonary circulation is established, the foramen ovale functionally closes as a result of changes in the relative pressure of the two atrial chambers, ensuring the separation of oxygen-depleted venous blood in the right atrium from the oxygenated blood entering the left atrium.

Hirsutism is the growth of excess hair in androgen dependent areas or in a male pattern. The phenomenon is found in conditions where there is abnormal androgen action. This can occur in adrenal lesions including congenital adrenal hyperplasia, and Cushing syndrome, or a failure to produce adequate female hormones such as PCOS and premature menopause. Similarly, drugs such as anabolic steroids, danazol and minoxidil can also cause hirsutism. Delayed puberty is unlikely to cause hirsutism.

Precocious puberty refers to the appearance of physical and hormonal signs of pubertal development at an earlier age than is considered normal.Most patients, particularly girls suspected of having central precocious puberty, are otherwise healthy children whose pubertal maturation begins at the early end of the normal distribution curveIn a series of more than 200 patients evaluated at a single medical centre, central precocious puberty occurred 5 times more often in girls than boys.GnRH-dependent precocious puberty is treated with GnRH agonists or Luteinizing Hormone Releasing Hormone (LHRH). Follow up every 4-6 months to ensure that progression of puberty has been arrestedFavourable signs include normalization of accelerated growth, reduction (or at least no increase) in size of breasts, and suppression of gonadotropin levels after a challenge of GnRHThe ideal testing frequency has not been established. Monitor bone age yearly to confirm that the rapid advancement seen in the untreated state has slowed, typically to a half year of bone age per year or less

Diazepam given rectally may be helpful in treating prolonged convulsions outside and within hospital when intravenous injection is not possible. A rectal dose of 0.5 mg/kg (maximum 10 mg) of injectable diazepam, undiluted or diluted with a 50% propylene glycol solution, can stop seizures in up to 80% of children. There are few adverse reactions. Seizures in children usually cease spontaneously within 5-10 minutes and are rarely associated with significant sequelae. The chance of a seizure stopping spontaneously decreases significantly after 10-15 minutes. Similarly, the efficacy of anticonvulsant medication decreases after 10-15 minutes of fitting and the risk of adverse effects increases. Convulsive seizures lasting longer than 30 minutes constitute status epilepticus and may be complicated by cardio respiratory depression and brain injury. Diazepam or clonazepam, given intravenously, is generally the drug of choice for the emergency treatment of convulsive status epilepticus. Intravenous diazepam may be difficult to administer to the young convulsing child and, because of the need for intravenous access, is not ideal for rapid treatment in the community by non-medical carers.