Dermatofibromas may be pigmented and are often larger than they appear. They frequently occur at the sites of previous trauma.

Dermatofibromas are small, noncancerous (benign) skin growths that can develop anywhere on the body but most often appear on the lower legs, upper arms, or upper back. These nodules are common in adults but are rare in children. They can be pink, grey, red, or brown in colour and may change colour over the years. They are firm and often feel like a stone under the skin. When pinched from the sides, the top of the growth may dimple inward. These lesions feel larger than they appear visually.

Dermatofibromas are usually painless, but some people experience tenderness or itching. Most often, a single nodule develops, but some can develop numerous dermatofibromas.

The pudendal nerve is formed by S1,2,4 anterior branches. It gives off the inferior haemorrhoid nerve before dividing terminally into the perineal nerve and the dorsal nerve of the clitoris or the penis. Thus, it is the principal motor and sensory nerve of the perineum.

The carotid triangle is a portion of the anterior triangle of the neck. It is bounded superiorly by the posterior belly of the digastric muscle, antero-inferiorly by the superior belly of omohyoid and posteriorly by the sternocleidomastoid. The floor is formed by the thyrohyoid, hyoglossus, middle and inferior pharyngeal constrictors and the roof is formed by the skin, superficial fascia, platysma and deep fascia.

During full inspiration, the lingual-of the left lung partially fills the costomediastinal recess. If the apex of the lung is fully filled with air, it would occupy the copula (the part of the pleura that extends above the first rib). The hilum is part of the lung where the neurovascular structures that form the root of the lung enter and leave the lung and doesn’t expand on inspiration. The middle lobe can expand to fill the costomediastinal recess, however, the middle lobe is on the right lung. The inferior lobe, during full inspiration, might fill the costodiaphragmatic recess.

The facial vein is the usual communication between the cavernous sinus and the pterygoid sinus. It is through this vein that an infected clot can travel to the cavernous sinus and cause infection. The pterygoid plexus is a venous plexus that is situated between the temporalis muscle and lateral pterygoid muscle, and partly between the two pterygoid muscles. The pterygoid plexus is connected to the facial vein by the deep facial vein. This connection is what makes this area where this sinus and the facial vein are located a danger zone. The danger zone or triangle of the face is the area from the corners of the mouth to the nose bridge. The sinus connection in this area makes it possible for infection to reach the cavernous sinus and at times cause meningitis.

Nephroblastoma is also known as Wilms’ tumour. It is a cancer of the kidneys that typically occurs in children. The median age of diagnose is approximately 3.5 years. With the current treatment, approximately 80-90% of children with Wilms’ tumour survive.

Glomerular filtration rate (GFR) is the volume of fluid filtered from the renal glomerular capillaries into the Bowman’s capsule per unit time. Clinically, this is often measured to determine renal function. Inulin was originally used as it is not reabsorbed by the kidney after glomerular filtration, therefore its rate of excretion is directly proportional to the rate of filtration of water and solutes across the glomerular filter. However, in clinical practice, creatinine clearance is used to measure GFR. Creatinine is an endogenous molecule, synthesised in the body, that is freely filtered by the glomerulus (but also secreted by the renal tubules in very small amounts). Creatinine clearance exceeds GFR due to creatinine secretion, and is therefore a close approximation of the GFR.

Shock is a life-threatening condition that occurs when the organs and tissues of the body are not receiving a sufficient flow of blood. Lack of blood flow, oxygen and nutrients results in the inability to function properly and damage to many organs. Shock requires immediate treatment because, if left untreated the impaired tissue perfusion and cellular hypoxia can cause irreversible tissue injury, collapse, coma or even death. There are various types of physiological shock, including: cardiogenic (due to heart damage), hypovolaemic (due to low total volume of blood or plasma), neurogenic (due to nervous system damage), septic (due to infections) and anaphylactic shock (due to allergic reactions). Hypovolaemic shock can be caused by blood loss due to trauma, internal bleeding or other fluid loss due to severe burns, prolonged diarrhoea, vomiting and sweating.

Hematocolpos means accumulation of blood in vagina and hematometra is accumulation of blood in the uterus. These are most likely seen with an imperforate hymen; which is seen I 1 in 2000 females. If spontaneous resolution does not occur, treatment involves making a hole in the hymen to allow discharge of menstrual blood.

Answer: Re-open the neck wound

Thyroidectomy: complications
Airway obstruction (compressing hematoma, tracheomalacia)

Incidence of hematoma is 1-2%, tracheomalacia incidence is <1%. Acute airway obstruction from hematoma may occur immediately postoperatively and is the most frequent cause of airway obstruction in the first 24 hours. Definitive therapy is opening the surgical incision to evacuate the hematoma. Re-intubation may be lifesaving for persistent airway obstruction. Consider awake fibreoptic intubation.

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.

A renogram, which may also be known as a MAG3 scan, allows a nuclear medicine physician or a radiologist to visualize the kidneys and learn more about how they are functioning.
After injection into the venous system, the compound is excreted by the kidneys and its progress through the renal system can be tracked with a gamma camera. A series of images are taken at regular intervals.

If the kidney is not getting blood for example, it will not be viewed at all, even if it looks structurally normal in medical ultrasonography or magnetic resonance imaging. If the kidney is getting blood, but there is an obstruction inferior to the kidney in the bladder or ureters, the radioisotope will not pass beyond the level of the obstruction, whereas if there is a partial obstruction then there is a delayed transit time for the MAG3 to pass. More information can be gathered by calculating time activity curves; with normal kidney perfusion, peak activity should be observed after 3–5 minutes. The relative quantitative information gives the differential function between each kidney’s filtration activity.

The cholera toxin (CTX or CT) is an oligomeric complex made up of six protein subunits: a single copy of the A subunit (part A), and five copies of the B subunit (part B), connected by a disulphide bond. The five B subunits form a five-membered ring that binds to GM1 gangliosides on the surface of the intestinal epithelium cells. The A1 portion of the A subunit is an enzyme that ADP-ribosylates G proteins, while the A2 chain fits into the central pore of the B subunit ring. Upon binding, the complex is taken into the cell via receptor-mediated endocytosis. Once inside the cell, the disulphide bond is reduced, and the A1 subunit is freed to bind with a human partner protein called ADP-ribosylation factor 6 (Arf6). Binding exposes its active site, allowing it to permanently ribosylate the Gs alpha subunit of the heterotrimeric G protein. This results in constitutive cAMP production, which in turn leads to secretion of H2O, Na+, K+, Cl−, and HCO3− into the lumen of the small intestine and rapid dehydration. The gene encoding the cholera toxin was introduced into V. cholerae by horizontal gene transfer.

Proctectomy with end stoma is the best operative strategy in severe perianal and/or rectal Crohn’s disease.

Surgical resection of Crohn’s disease does not provide a complete cure but it may produce substantial symptomatic improvement. Indications for surgery include complications such as fistulae, abscess formation, and strictures.

Colonoscopy and a small bowel study (e.g. MR enteroclysis imaging) are used to stage Crohn’s disease to facilitate decision-making regarding surgery.
Complex perianal fistulae are best managed with long-term draining seton sutures. Severe perianal and/or rectal Crohn’s disease usually require proctectomy with formation of end stoma. Ileoanal pouch reconstruction carries a high risk of fistula formation and pouch failure and is, therefore, not recommended. Terminal ileal Crohn’s remains one of the most common form of the disease, and it may be treated with limited ileocaecal resections.

The latissimus dorsi forms the posterior wall of the axilla along with the scapula. It is responsible for extension, adduction, transverse extension also known as horizontal abduction, flexion from an extended position, and (medial) internal rotation of the shoulder joint. It also has a synergistic role in extension and lateral flexion of the lumbar spine.

Adrenocortical carcinomas are rare tumours with reported incidence being only two in a million. However, they have a poor prognosis. These are large tumours and range from 4-10 cm in diameter. They arise from the adrenal cortex and 10% cases are bilateral. 50-80% are known to be functional, leading to Cushing syndrome. Even though the tumour affects both sexes equally, functional tumours are slightly commoner in women and non-functional tumours are commoner in men. As compared to women, men also develop this tumour at an older age and seem to have a poorer prognosis.

The patient has Pulmonary embolism (PE).
PE is when a thrombus becomes lodged in an artery in the lung and blocks blood flow to the lung. Pulmonary embolism usually arises from a thrombus that originates in the deep venous system of the lower extremities; however, it rarely also originates in the pelvis, renal, upper extremity veins, or the right heart chambers. After travelling to the lung, large thrombi can lodge at the bifurcation of the main pulmonary artery or the lobar branches and cause hemodynamic compromise.
The classic presentation of PE is the abrupt onset of pleuritic chest pain, shortness of breath, and hypoxia. However, most patients with pulmonary embolism have no obvious symptoms at presentation. Rather, symptoms may vary from sudden catastrophic hemodynamic collapse to gradually progressive dyspnoea.
Physical signs of pulmonary embolism include the following:
Tachypnoea (respiratory rate >16/min): 96%
Rales: 58%
Accentuated second heart sound: 53%
Tachycardia (heart rate >100/min): 44%
Fever (temperature >37.8°C [100.04°F]): 43%
Diaphoresis: 36%
S3 or S4 gallop: 34%
Clinical signs and symptoms suggesting thrombophlebitis: 32%
Lower extremity oedema: 24%
Cardiac murmur: 23%
Cyanosis: 19%
Management
Anticoagulation and thrombolysis
Immediate full anticoagulation is mandatory for all patients suspected of having DVT or PE. Diagnostic investigations should not delay empirical anticoagulant therapy.
Thrombolytic therapy should be used in patients with acute pulmonary embolism who have hypotension (systolic blood pressure< 90 mm Hg) who do not have a high bleeding risk and in selected patients with acute pulmonary embolism not associated with hypotension who have a low bleeding risk and whose initial clinical presentation or clinical course suggests a high risk of developing hypotension.
Long-term anticoagulation is critical to the prevention of recurrence of DVT or pulmonary embolism because even in patients who are fully anticoagulated, DVT and pulmonary embolism can and often do recur.
Thrombolytic agents used in managing pulmonary embolism include the following:
– Alteplase
– Reteplase

Heparin should be given to patients with intermediate or high clinical probability before imaging.
Unfractionated heparin (UFH) should be considered (a) as a first dose bolus, (b) in massive PE, or (c) where rapid reversal of effect may be needed.
Otherwise, low molecular weight heparin (LMWH) should be considered as preferable to UFH, having equal efficacy and safety and being easier to use.
Oral anticoagulation should only be commenced once venous thromboembolism (VTE) has been reliably confirmed.
The target INR should be 2.0–3.0; when this is achieved, heparin can be discontinued.
The standard duration of oral anticoagulation is: 4–6 weeks for temporary risk factors, 3 months for first idiopathic, and at least 6 months for other; the risk of bleeding should be balanced with that of further VTE.

Small cell lung cancer is a highly aggressive form of lung cancer. It is thought to originate from neuroendocrine cells in the bronchus called Feyrter cells and is often associated to ectopic production of hormones like ADH and ACTH that result in paraneoplastic syndromes and Cushing’s syndrome.

Transverse sinus: part of pericardial cavity that is behind the aorta and pulmonary trunk and in front of the superior vena cava separating the outflow vessels from the inflow vessels.
Oblique pericardial sinus: is behind the left atrium where the visceral pericardium reflects onto the pulmonary veins and the inferior vena cava. Sliding a finger under the heart will take you to this sinus.
Coronary sinus: large vein that drains the heart into the right atrium. Located on the surface of the heart.
Coronary sulcus: groove on the heart demarcating the atria from the ventricles.
Costomediastinal recess: part of the pleural sac where the costal pleura transitions to become the mediastinal pleura.
Sulcus terminalis: a groove between the right atrium and the vena cava.

Answer: Hemopericardium

Hemopericardium refers to the presence of blood within the pericardial cavity, i.e. a sanguineous pericardial effusion. If enough blood enters the pericardial cavity, then a potentially fatal cardiac tamponade can occur. There is a very long list of causes but some of the more common are:
-ruptured myocardial infarction
-ruptured left ventricular aneurysm
-aortic dissection
-pericarditis
-trauma
-blunt/penetrating/deceleration
-iatrogenic, e.g. pacemaker wire insertion
-cardiac malignancies
-ruptured coronary artery aneurysm
-post-thrombolysis

Cardiac tamponade is a clinical syndrome caused by the accumulation of fluid in the pericardial space, resulting in reduced ventricular filling and subsequent hemodynamic compromise. The condition is a medical emergency, the complications of which include pulmonary oedema, shock, and death.
Symptoms vary with the acuteness and underlying cause of the tamponade. Patients with acute tamponade may present with dyspnoea, tachycardia, and tachypnoea. Cold and clammy extremities from hypoperfusion are also observed in some patients. Other symptoms and signs may include the following:
Elevated jugular venous pressure

Pulsus paradoxus

Chest pressure

Decreased urine output

Confusion

Dysphoria

The central retinal artery supplies all the nerve fibres that form the optic nerve, which carries the visual information to the lateral geniculate nucleus of the thalamus. Thus if the central retinal artery gets occluded, there is complete loss of vision in that eye and the entire retina (with the exception of the fovea) becomes pale, swollen and opaque while the central fovea still appears reddish (this is because the choroid colour shows through). This is the basis of the famous Cherry red spot seen on examination of the retina on fundoscopy of a central retinal artery occlusion (CRAO).

The ophthalmic nerve is the smallest of the three trigeminal divisions. The cutaneous branches of the ophthalmic nerve supply the conjunctiva, the skin over the forehead, the upper eyelid, and much of the external surface of the nose.

neutrophils are the most abundant cell type of the WBC. These phagocytes are found normally in the blood and increase in number are seen during an acute inflammation. These the percentages of WBC in blood Neutrophils: 40 to 60%
Lymphocytes: 20 to 40%
Monocytes: 2 to 8%
Eosinophils: 1 to 4%
Basophils: 0.5 to 1%
Band (young neutrophil): 0 to 3%. eosinophils, basophils, neutrophils are known as granulocytes and monocytes and lymphocytes as agranulocytes.

Under normal conditions the renal clearance of glucose is zero, since glucose is completely reabsorbed in the renal tubules and not excreted. Glycosuria – the excretion of glucose into the urine- is nearly always caused by elevated blood glucose levels, most commonly due to untreated diabetes mellitus.

Answer: The burn area is extremely painful until skin grafted

Third-degree burns destroy the epidermis and dermis. Third-degree burns may also damage the underlying bones, muscles, and tendons. The burn site appears white or charred. There is no sensation in the area since the nerve endings are destroyed. These are not normally painful until after skin grafting is done since the nerve endings have been destroyed.

Complications related to stapled anastomoses include bleeding, device failure, and anastomotic failure, which include stricture or leak.
Stricture: Patient discomfort, need for additional procedures
Bleeding: Hemodynamic implications, difficult intraoperative visualization
Anastomotic leak: Increase in local recurrence, decreased overall survival, sepsis, need for diverting ostomy, increased hospital cost, increased use of hospital resources, decreased quality of life.
Anastomotic bleeding is a common complication of stapled anastomoses, and it can lead to hemodynamic instability and anaemia, sometimes requiring transfusion or additional procedures. To this end, there are efforts aimed at reducing staple line haemorrhage by using buttressing techniques.

Answer: Intestinal malrotation

During normal abdominal development, the 3 divisions of the GI tract (i.e., foregut, midgut, hindgut) herniate out from the abdominal cavity, where they then undergo a 270º counter clockwise rotation around the superior mesenteric vessels. Following this rotation, the bowels return to the abdominal cavity, with fixation of the duodenojejunal loop to the left of the midline and the cecum in the right lower quadrant.

Intestinal malrotation refers to any variation in this rotation and fixation of the GI tract during development. Interruption of typical intestinal rotation and fixation during foetal development can occur at a wide range of locations; this leads to various acute and chronic presentations of disease. The most common type found in paediatric patients is incomplete rotation predisposing to midgut volvulus, requiring emergent operative intervention.

Acute midgut volvulus

Usually occurs during the first year of life

Sudden onset of bilious emesis

Diffuse abdominal pain out of proportion to physical examination

Acute duodenal obstruction

This anomaly is usually recognized in infants and is due to compression or kinking of the duodenum by peritoneal bands (Ladd bands).

Patients present with forceful vomiting, which may or may not be bile-stained, depending on the location of the obstruction with respect to the entrance of the common bile duct (ampulla of Vater).

Malrotation may occur as an isolated anomaly or in association with other congenital anomalies; 30-62% of children with malrotation have an associated congenital anomaly. All children with diaphragmatic hernia, gastroschisis, and omphalocele have intestinal malrotation by definition. Additionally, malrotation is seen in approximately 17% of patients with duodenal atresia and 33% of patients with jejunoileal atresia.

A fibroadenoma is a painless, unilateral, benign (non-cancerous) breast tumour that is a solid, not fluid-filled, lump. It occurs most commonly in women between the age of 14 to 35 years but can be found at any age. Fibroadenomas shrink after menopause, and therefore, are less common in post-menopausal women. Fibroadenomas are often referred to as a breast mouse due to their high mobility. Fibroadenomas are a marble-like mass comprising both epithelial and stromal tissues located under the skin of the breast. These firm, rubbery masses with regular borders are often variable in size.

Duct ectasia, also known as mammary duct ectasia, is a benign (non-cancerous) breast condition that occurs when a milk duct in the breast widens and its walls thicken. This can cause the duct to become blocked and lead to fluid build-up. It’s more common in women who are getting close to menopause. But it can happen after menopause, too.

Fat necrosis is a benign condition and does not increase the risk of developing breast cancer. It can occur anywhere in the breast and can affect women of any age. Men can also get fat necrosis, but this is very rare.

Breast cysts are a benign condition. They’re one of the most common causes of a breast lump, and can develop in either one or both breasts. It’s thought they develop naturally as the breast changes with age due to normal changes in hormone levels. It’s common to have more than one cyst. Breast cysts can feel soft or hard and can be any size, ranging from a few millimetres to several centimetres. They’re usually oval or round in shape and can develop quickly.

Atypical hyperplasia is a precancerous condition that affects cells in the breast. Atypical hyperplasia describes an accumulation of abnormal cells in the breast.

Acute pancreatitis is an inflammatory condition of the pancreas most commonly caused by biliary tract disease or alcohol abuse. Damage to the pancreas causes local release of digestive proteolytic enzymes that autodigest pancreatic tissue. Acute pancreatitis usually presents with epigastric pain radiating to the back, nausea and vomiting, and epigastric tenderness on palpation. The diagnosis is made based on the clinical presentation, elevated serum pancreatic enzymes, and findings on imaging (CT, MRI, ultrasound) that suggest acute pancreatitis. Treatment is mostly supportive and includes bowel rest, fluid resuscitation, and pain medication. Enteral feeding is usually quickly resumed once the pain and inflammatory markers begin to subside. Interventional procedures may be indicated for the treatment of underlying conditions, such as ERCP or cholecystectomy in gallstone pancreatitis. Localized complications of pancreatitis include necrosis, pancreatic pseudocysts, and abscesses. Systemic complications involve sepsis, ARDS, organ failure, and shock and are associated with a considerable rise in mortality.

The Ranson score is used to predict the severity of acute pancreatitis:
At admission
age in years > 55 years
white blood cell count > 16000 cells/mm3
blood glucose > 11.1 mmol/L (> 200 mg/dL)
serum AST > 250 IU/L
serum LDH > 350 IU/L

At 48 hours
Calcium (serum calcium < 2.0 mmol/L (< 8.0 mg/dL)
Haematocrit fall >10%
Oxygen (hypoxemia PO2 < 60 mmHg)
BUN increased by 1.8 or more mmol/L (5 or more mg/dL) after IV fluid hydration
Base deficit (negative base excess) > 4 mEq/L
Sequestration of fluids > 6 L

Interpretation If the score ≥ 3, severe pancreatitis likely. If the score < 3, severe pancreatitis is unlikely Or Score 0 to 2 : 2% mortality Score 3 to 4 : 15% mortality Score 5 to 6 : 40% mortality Score 7 to 8 : 100% mortality

Atrophy is characterised by the breakdown of intracellular components along with organelles and packing them into vacuoles known as autophagic vacuoles. This is an adaptive response that separates the damaged cellular structures from the rest of the cells.