The development of oedema in nephrotic syndrome has traditionally been viewed as an underfill mechanism. According to this view, urinary loss of protein results in hypoalbuminemia and decreased plasma oncotic pressure. As a result, plasma water translocates out of the intravascular space and results in a decrease in intravascular volume. In response to the underfilled circulation, effector mechanisms are then activated that signal the kidney to secondarily retain salt and water. While an underfill mechanism may be responsible for oedema formation in a minority of patients, recent clinical and experimental findings would suggest that oedema formation in most nephrotic patients is the result of primary salt retention. Direct measurements of blood and plasma volume or measurement of neurohumoral markers that indirectly reflect effective circulatory volume are mostly consistent with either euvolemia or a volume expanded state. The ability to maintain plasma volume in the setting of a decreased plasma oncotic pressure is achieved by alterations in transcapillary exchange mechanisms known to occur in the setting of hypoalbuminemia that limit excessive capillary fluid filtration.

The immediate treatment of hypercalcaemia involves intravenous fluid resuscitation. This may be complemented with the use of bisphosphonates and sometimes, diuretics. However, fluids are administered first. Normal saline is usually preferred for this over other solutions.

Urgent management in hypercalcaemia is indicated if:
1. Serum calcium level >3.5 mmol/L
2. Reduced consciousness
3. Severe abdominal pain
4. Pre-renal failure

Management options include:
1. Intravenous fluid resuscitation with 3–6 litres of 0.9% normal saline in 24 hours
2. Concurrent administration of calcitonin to help lower calcium levels
3. Medical therapy (usually if corrected calcium >3.0mmol/L)

Answer: Surgery over the next few days

Inguinal hernia is a type of ventral hernia that occurs when an intra-abdominal structure, such as bowel or omentum, protrudes through a defect in the abdominal wall. Inguinal hernias do not spontaneously heal and must be surgically repaired because of the ever-present risk of incarceration. Generally, a surgical consultation should be made at the time of diagnosis, and repair (on an elective basis) should be performed very soon after the diagnosis is confirmed.

The infant or child with an inguinal hernia generally presents with an obvious bulge at the internal or external ring or within the scrotum. The parents typically provide the history of a visible swelling or bulge, commonly intermittent, in the inguinoscrotal region in boys and inguinolabial region in girls.
The swelling may or may not be associated with any pain or discomfort.

Congenital neck masses are developmental anomalies typically seen in infants or children. Common conditions include thyroglossal duct cysts, branchial cleft cysts, and cystic hygromas. These malformations present as painless neck masses, which can cause dysphagia, respiratory distress, and neck pain due to compression of surrounding structures. The location of the mass depends on the embryological structure the cysts arise from. Diagnosis is made based on clinical findings and imaging results (ultrasound, CT, MRI), which also help in surgical planning. Treatment consists of complete surgical resection to prevent recurrence and complications such as infection or abscess formation.
The thyroglossal cyst is present from birth and usually detected during early childhood. It presents as a painless, firm midline neck mass, usually near the hyoid bone, which elevates with swallowing and tongue protrusion. May cause dysphagia or neck/throat pain if the cyst enlarges.

Answer: Torsion of a testicular hydatid

The appendix testis (or hydatid of Morgagni) is a vestigial remnant of the Müllerian duct, present on the upper pole of the testis and attached to the tunica vaginalis. It is present about 90% of the time. The appendix of testis can, occasionally, undergo torsion (i.e. become twisted), causing acute one-sided testicular pain and may require surgical excision to achieve relief. One third of patients present with a palpable blue dot discoloration on the scrotum. This is nearly diagnostic of this condition. If clinical suspicion is high for the serious differential diagnosis of testicular torsion, a surgical exploration of the scrotum is warranted. Torsion of the appendix of testis occurs at ages 0-15 years, with a mean at 10 years, which is similar to that of testicular torsion.

Occasionally a torsion of the hydatid of Morgagni can produce symptoms mimicking those created by a testicular torsion; a torsion of the hydatid, however, does not lead to any impairment of testicular function.
Absence of the cremasteric reflex is a sign of testicular torsion. This therefore confirms that the diagnosis is Torsion of a testicular hydatid.

Lymphatic spread indicates poor prognosis. Presence of family history is not a prognostic factor despite being linked to higher incidence. Aneuploidy is a poor prognostic factor. A breast tumour positive for oestrogen receptors is a good prognostic factor as it increases the responsiveness of the tumour to certain therapies. In-situ tumours carry the best prognosis.

Hyperbilirubinemia can be caused due to increased bilirubin production, decreased liver uptake or conjugation, or decreased biliary excretion. Normal bilirubin level is less than 1.2 mg/dl (<20 μmol/l), with most of it unconjugated. Elevated unconjugated bilirubin (indirect bilirubin fraction >85%) can occur due to haemolysis (increased bilirubin production) or defective liver uptake/conjugation (Gilbert syndrome). Such increases are less than five-fold usually (<6 mg/dl or <100 μmol/l) unless there is coexistent liver disease.

Answer: Staphylococcus aureus

Mastitis is defined as inflammation of the breast. Although it can occur spontaneously or during lactation, this discussion is limited to mastitis in breastfeeding women, with mastitis defined clinically as localized, painful inflammation of the breast occurring in conjunction with flu-like symptoms (e.g., fever, malaise). Mastitis is especially problematic because it may lead to the discontinuation of breast-feeding, which provides optimal infant nutrition. Mastitis occurs in approximately 10 percent of U.S. mothers who are breastfeeding, and it can lead to the cessation of breastfeeding. The risk of mastitis can be reduced by frequent, complete emptying of the breast and by optimizing breastfeeding technique. Sore nipples can precipitate mastitis. The differential diagnosis of sore nipples includes mechanical irritation from a poor latch or infant mouth anomalies, such as cleft palate or bacterial or yeast infection. The diagnosis of mastitis is usually clinical, with patients presenting with focal tenderness in one breast accompanied by fever and malaise. Treatment includes changing breastfeeding technique, often with the assistance of a lactation consultant. When antibiotics are needed, those effective against Staphylococcus aureus (e.g., dicloxacillin, cephalexin) are preferred. As methicillin-resistant S. aureus becomes more common, it is likely to be a more common cause of mastitis, and antibiotics that are effective against this organism may become preferred. Continued breastfeeding should be encouraged in the presence of mastitis and generally does not pose a risk to the infant. Breast abscess is the most common complication of mastitis. It can be prevented by early treatment of mastitis and continued breastfeeding. Once an abscess occurs, surgical drainage or needle aspiration is needed. Breastfeeding can usually continue in the presence of a treated abscess.

Answer: Aspirin

Aspirin increases bleeding time when taken orally. Aspirin causes several different effects in the body, mainly the reduction of inflammation, analgesia (relief of pain), the prevention of clotting, and the reduction of fever. Much of this is believed to be due to decreased production of prostaglandins and TXA2. Aspirin’s ability to suppress the production of prostaglandins and thromboxanes is due to its irreversible inactivation of the cyclooxygenase (COX) enzyme. Cyclooxygenase is required for prostaglandin and thromboxane synthesis. Prostaglandins are local chemical messengers that exert multiple effects including but not limited to the transmission of pain information to the brain, modulation of the hypothalamic thermostat, and inflammation. They are produced in response to the stimulation of phospholipids within the plasma membrane of cells resulting in the release of arachidonic acid (prostaglandin precursor). Thromboxanes are responsible for the aggregation of platelets that form blood clots.
Low-dose, long-term aspirin use irreversibly blocks the formation of thromboxane A2 in platelets, producing an inhibitory effect on platelet aggregation.

Antihypertensive and antidiabetic medications do not need to be stopped when a patient is undergoing local anaesthesia. Steroid (Prednisolone) use cannot be stopped abruptly; tapering the drug gives the adrenal glands time to return to their normal patterns of secretion. Withdrawal symptoms and signs (weakness, fatigue, decreased appetite, weight loss, nausea, vomiting, diarrhoea, abdominal pain) can mimic many other medical problems. Some may be life-threatening.

Achalasia is an oesophageal motor disorder characterized by aperistalsis of the oesophageal body and lack of relaxation of the lower sphincter in response to swallows.
Achalasia cardia is one of the common causes of motor dysphagia. Pathophysiologically, achalasia cardia is caused by loss of inhibitory ganglion in the myenteric plexus of the oesophagus. In the initial stage, degeneration of inhibitory nerves in the oesophagus results in unopposed action of excitatory neurotransmitters such as acetylcholine, resulting in high amplitude non-peristaltic contractions (vigorous achalasia); progressive loss of cholinergic neurons over time results in dilation and low amplitude simultaneous contractions in the oesophageal body (classic achalasia).

Answer: Acute Epstein Barr virus infection

The Epstein–Barr virus is one of eight known human herpesvirus types in the herpes family, and is one of the most common viruses in humans. Infection with Epstein-Barr virus (EBV) is common and usually occurs in childhood or early adulthood.
EBV is the cause of infectious mononucleosis, an illness associated with symptoms and signs like:
fever,
fatigue,
swollen tonsils,
headache, and
sweats,
sore throat,
swollen lymph nodes in the neck, and
sometimes an enlarged spleen.
Although EBV can cause mononucleosis, not everyone infected with the virus will get mononucleosis. White blood cells called B cells are the primary targets of EBV infection.

IL-5 is produced by TH2 helper cells and by mast cells. They stimulate increased secretion of immunoglobulins and stimulate B cell growth. They are the major regulators in eosinophil activation and control. They are also released from eosinophils and mast cells in asthmatic patients and are associate with a many other allergic conditions.

Parsonage-Turner Syndrome (PTS), also referred to as idiopathic brachial plexopathy or neuralgic amyotrophy, is a rare disorder consisting of a complex constellation of symptoms with abrupt onset of shoulder pain, usually unilaterally, followed by progressive neurologic deficits of motor weakness, dysesthesias, and numbness. Although the aetiology of the syndrome is unclear, it is reported in various clinical situations, including postoperatively, postinfectious, posttraumatic, and postvaccination.
The most common associated risk factor is a recent viral illness.
The pain is not positional and usually worse at night and may be associated with awakenings from sleep. There are typically no constitutional symptoms associated with the syndrome. The duration of pain is almost always self-limiting, lasting 1 to 2 weeks, but on rare occasion persisting for longer periods.
In the earliest stages of this condition (the first few weeks), pain management with opiates, NSAIDs, and neuroleptics is the mainstay of treatment. Acupuncture and transcutaneous electrical nerve stimulation (TENS) can also be adjuncts to medications. Oral steroids have been recommended by some, but there is poor literature evidence to support its efficacy.
Physical therapy plays an important role in the treatment of this condition. Modalities such as TENS can help in pain management.

Hypernatremia, characterised by a high serum sodium concentration, is rarely associated with volume overload (hypervolemia). A hypovolaemic hypernatremia may be seen during excessive administration of hypertonic sodium bicarbonate, hypertonic saline or hyperalimentation.

Carcinoid syndrome occurs in ∼20% of cases of well-differentiated endocrine tumours of the jejunum or ileum (midgut neuroendocrine tumours (NET) and consists of (usually) dry flushing (without sweating; 70% of cases) with or without palpitations, diarrhoea (50% of cases) and intermittent abdominal pain (40% of cases); in some patients, there is also lacrimation and rhinorrhoea.
Carcinoid syndrome occurs less often with NETs of other origins and is very rare in association with rectal NETs. It is usually due to metastasis to the liver, with the release of vasoactive compounds, including biogenic amines (e.g., serotonin and tachykinins), into the systemic circulation. However, it may also occur in the absence of liver metastases if there is direct retroperitoneal involvement, with venous drainage bypassing the liver. Pain due to hepatic enlargement may also be a presenting feature, as may upper right abdominal pain (similar to that of pulmonary infarction) secondary to either haemorrhage into, or necrosis of, a hepatic secondary tumour. Wheezing and pellagra are less common presenting features. CHD is present in ∼20% of patients at presentation and usually indicates that the syndrome has been present for several years.

The aim of treatment should be curative where possible but it is palliative in the majority of cases.
Surgery is the only curative treatment.
Administration of specific medications to treat symptoms should, therefore, start as soon as clinical and biochemical signs indicate the presence of hypersecretory NETs, even before the precise localisation of primary and metastatic lesions is confirmed.

The only proven hormonal management of NETs is by the administration of somatostatin analogues.
Somatostatin analogues bind principally to SSTR subtypes 2 (with high affinity) and 5 (with lower affinity), thus inhibiting the release of various peptide hormones in the gut, pancreas and pituitary; they also antagonise growth factor effects on tumour cells, and, at very high dosage, may induce apoptosis. The effects of somatostatin analogues are demonstrable as biochemical response rates (inhibition of hormone production) in 30–70% of patients and as symptomatic control in the majority of patients.
There are two commercially available somatostatin analogues: octreotide and lanreotide.

Angio-oedema, is the rapid swelling of the skin, mucosa and submucosal tissues. The underlying mechanism typically involves histamine or bradykinin. The version related to histamine is to due an allergic reaction to agents such as insect bites, food, or medications. The version related to bradykinin may occur due to an inherited C1 esterase inhibitor deficiency, medications e.g. angiotensin converting enzyme inhibitors, or a lymphoproliferative disorder.

Nasal injuries can be challenging to manage and where there is tissue loss, it can be difficult to primarily close them and obtain a satisfactory aesthetic result. Debridement together with a rotational skin flap would produce the best results.

A rotation flap is a semi-circular skin flap that is rotated into the defect on a fulcrum point. It provides the ability to mobilize large areas of tissue with a wide vascular base for reconstruction. Rotation flaps may be pedicled or free. Pedicled flaps are more reliable but are limited in the range of movement. Free flaps have increased range but carry greater risk of breakdown as they require vascular anastomosis.

Repair of an inguinal hernia under local anaesthesia has a short operative time, and patients are usually ambulant immediately after. Furthermore, the family history of this patient is unlikely to be significant and therefore, he is at a very low risk of developing a pulmonary embolism (PE).

Deep vein thrombosis (DVT) may develop insidiously in many surgical patients. If left untreated, it may progress to PE. The following surgical patients are at increased risk of developing DVT:

1. Surgery greater than 90 minutes at any site or greater than 60 minutes if the procedure involves lower limbs or pelvis
2. Acute admissions with inflammatory process involving the abdominal cavity
3. Expected significant reduction in mobility
4. Age over 60 years
5. Known malignancy
6. Thrombophilia
7. Previous thrombosis
8. BMI >30 kg/m2
9. Taking hormone replacement therapy or contraceptive pills
10. Varicose veins with phlebitis

Thromboprophylaxis can be mechanical or therapeutic. The former includes:
1. Early ambulation after surgery: cheap and effective
2. Compression stockings (contraindicated in peripheral arterial disease)
3. Intermittent pneumatic compression devices
4. Foot impulse devices

Therapeutic agents for thromboprophylaxis are:
1. Low-molecular-weight heparin (LMWH)
2. Unfractionated heparin
3. Dabigatran

Iron deficiency anaemia is the most common type of anaemia. It can occur due to deficiency of iron due to decreased intake or due to faulty absorption. An MCV less than 80 will indicated iron deficiency anaemia. On the smear the RBC will be microcytic hypochromic and will also show piokilocytosis. iron profiles tests are important to make a diagnosis. Clinically the patient will be pale and lethargic.

Based on the aforementioned findings in this case, the most likely diagnosis is medullary carcinoma of the thyroid associated with multiple endocrine neoplasia (MEN).

Medullary thyroid cancer is a tumour of the parafollicular cells (C cells) of the thyroid and is neural crest in origin. It may be familial and occur as part of the MEN 2A disease spectrum. Less than 10% of thyroid cancers are of this type with patients typically presenting as children or young adults. Diarrhoea occurs in 30% of the cases. In association with MEN syndromes, medullary thyroid cancers are always bilateral and multicentric. Spread may either be lymphatic or haematogenous, and as these tumours are not derived primarily from thyroid cells, they are not responsive to radioiodine.

Toxic nodular goitre is very rare. In sporadic medullary carcinoma of the thyroid, patients typically present with a unilateral solitary nodule and it tends to spread early to the lymph nodes in neck.

Mesenteric venous thrombosis (MVT) is a blood clot in one or more of the major veins that drain blood from the intestine. The superior mesenteric vein is most commonly involved. The exact cause of MVT is unknown. However, there are many diseases that can lead to MVT. Many of the diseases cause swelling (inflammation) of the tissues surrounding the veins, and include:
Appendicitis
Cancer of the abdomen
Diverticulitis
Liver disease with cirrhosis
High blood pressure in the blood vessels of the liver
Abdominal surgery or trauma
Pancreatitis
Inflammatory bowel disorders
Heart failure
Protein C or S deficiencies
Polycythaemia vera
Essential thrombocythemia
People who have disorders that make the blood more likely to stick together (clot) have a higher risk for MVT. Birth control pills and oestrogen medicines also increase risk.

MVT is more common in men than women. It mainly affects middle aged or older adults. Symptoms may include any of the following:
Abdominal pain, which may get worse after eating and over time; Bloating; Constipation; Bloody diarrhoea; Fever; Septic shock; Lower gastrointestinal bleeding; Vomiting and nausea.
Blood thinners (most commonly heparin or related medicines) are used to treat MVT when there is no associated bleeding. In some cases, medicine can be delivered directly into the clot to dissolve it. This procedure is called thrombolysis. Less often, the clot is removed by thrombectomy.

The foramen ovale is an oval shaped opening in the middle cranial fossa located at the posterior base of the greater wing of the sphenoid bone, lateral to the lingula. It transmits the mandibular division of the trigeminal nerve (CN Vc), accessory meningeal artery, emissary veins between the cavernous sinuses and pterygoid plexus, otic ganglion, and occasionally the nervus spinosus and lesser petrosal nerve.

Bronchial carcinoids are neuroendocrine tumours that arise from Kulchitsky’s cells of the bronchial epithelium. Kulchitsky’s cells belong to the diffuse endocrine system. Patients affected by this tumour may be asymptomatic or may present with symptoms of airway obstruction, like dyspnoea, wheezing, and cough. Other common findings are recurrent pneumonia, haemoptysis, chest pain and paraneoplastic syndromes. Chest radiographs are abnormal in the majority of cases. Peripheral carcinoids usually present as a solitary pulmonary nodule. For central lesions common findings include hilar or perihilar masses with or without atelectasis, bronchiectasis, or consolidation. Bronchial carcinoids most commonly arise in the large bronchi causing obstruction.

Hypovolemia can be recognized by tachycardia, diminished blood pressure, and the absence of perfusion as assessed by skin signs (skin turning pale) and/or capillary refill time. The patient may feel dizzy, faint, nauseated, or very thirsty. Common causes of hypovolemia are loss of blood, loss of plasma which occurs in severe burns and lesions discharging fluid, loss of body sodium and consequent intravascular water which may occur in cases of diarrhoea and vomiting. In this case the cause of patients hypotension is due to hypovolemia from both loss of plasma and blood.

The glossopharyngeal nerve provides parasympathetic innervation for the parotid salivary gland via the auriculotemporal nerve. The facial nerve supplies the parasympathetic innervation of the lacrimal, nasal, sublingual and submandibular glands.

Tissue factor (TF), also known as ‘factor III’ or ‘thromboplastin’, is an anti-coagulation protein that initiates the extrinsic coagulation. TF acts as a transmembrane receptor for Factor VII/VIIa . It is expressed by endothelial cells but also certain tissues, such as the heart and brain.

Poiseuille-Hagen formula for flow in along narrow tube states that F = (PA– PB) × (Π/8) × (1/η) × (r4/l) where F = flow, PA– PB = pressure difference between the two ends of the tube, η = viscosity, r = radius of tube and L = length of tube. Also, flow is given by pressure difference divided by resistance. Hence, R = 8ηL ÷ Πr4. Hence, the resistance of the vessel changes in inverse proportion to the fourth power of the diameter. So, if the diameter of the vessel is increased to twice the original, it will lead to decrease in resistance to one-sixteenth its initial value.

At the superficial inguinal ring, the pubic tubercle would be felt as a bony prominence lateral to the edge of the spermatic cord. This tubercle is the point of attachment of the inguinal ligament that makes up the floor of the inguinal canal.
Pecten pubis is the ridge on the superior surface of the superior pubic ramus and the point of attachment of the pectineal ligament.
The pubic symphysis is the joint between the two pubic bones and the iliopubic eminence is a bony process on the pubis found near the articulation of the pubis and the ilium.
The iliopectineal line is formed by the arcuate line of the ilium and the pectineal line of the pubis. It is the line that marks the transition between the abdominal and pelvic cavity.
The sacral promontory is found on the posterior wall of the pelvis and would not be felt through the inguinal ring.

Transplant renal artery stenosis (TRAS) is a well-recognized vascular complication after kidney transplant. It occurs most frequently in the first 6 months after kidney transplant, and is one of the major causes of graft loss and premature death in transplant recipients. Transplant renal artery stenosis (TRAS) is the narrowing of the transplant renal artery, impeding blood flow to the allograft. It accounts for 1–5% cases of post-transplant hypertension. Patients with TRAS have activated RAAS and usually present with worsening or refractory hypertension, fluid retention and/or allograft dysfunction without evidence of rejection.
Percutaneous transluminal angioplasty with stent placement is generally the first-line therapy to correct hemodynamically significant stenosis in TRAS, especially for lesions that are short, linear and distal to the anastomosis.

Achalasia is a failure of the lower oesophageal sphincter (LES) to relax that is caused by the degeneration of inhibitory neurons within the oesophageal wall. It is classified as either primary (idiopathic) or secondary (in the context of another disease). In patients with achalasia, the chief complaint is dysphagia to both solids and liquids, although regurgitation, retrosternal pain, and weight loss may also occur. Upper endoscopy, barium esophagram, and oesophageal manometry play complementary roles in the diagnosis of achalasia. While upper endoscopy and/or barium esophagram are often obtained initially, manometry usually confirms the diagnosis, and upper endoscopy is indicated to rule out a malignant underlying cause. In good surgical candidates, achalasia is usually treated with pneumatic dilation or myotomy. In most other cases, an injection of botulinum toxin is attempted. If these measures fail to provide relief, medical therapy (e.g., nifedipine) is indicated.