Phyllodes tumours are large, quickly growing tumours which arise from the periductal stroma of the breast. These are fibroepithelial tumours and account for less than 1% of breast cancers. These tumours can be benign, borderline or malignant based on the histology. The tumour usually affects adult women, mostly between the age of 40 to 50 years. It can be confused with fibroadenoma, which however affects much younger patients.

Acute subdural hematoma is usually caused by external trauma that creates tension in the wall of a bridging vein as it passes between the arachnoid and dural layers of the brain’s lining—i.e., the subdural space. The circumferential arrangement of collagen surrounding the vein makes it susceptible to such tearing.

Acute bleeds often develop after high-speed acceleration or deceleration injuries. They are most severe if associated with cerebral contusions. Though much faster than chronic subdural bleeds, acute subdural bleeding is usually venous and therefore slower than the arterial bleeding of an epidural haemorrhage. Acute subdural hematomas due to trauma are the most lethal of all head injuries and have a high mortality rate if they are not rapidly treated with surgical decompression. The mortality rate is higher than that of epidural hematomas and diffuse brain injuries because the force required to cause subdural hematomas tends to cause other severe injuries as well.

Generally, acute subdural hematomas are less than 72 hours old and are hyperdense compared with the brain on computed tomography scans. The subacute phase begins 3-7 days after acute injury. Chronic subdural hematomas develop over the course of weeks and are hypodense compared with the brain. However, subdural hematomas may be mixed in nature, such as when acute bleeding has occurred into a chronic subdural hematoma.
Lateralizing findings include ipsilateral pupillary dilatation with impaired reaction and motor deficit. Usually the pupillary dilatation will be ipsilateral and motor deficit (hemiparesis or hemiplegia) will be contralateral to the site of subdural hematoma.

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 space.
Cardiac notch: indentation of the ‘of the heart’ on the superior lobe of the left lung.
Hilar reflection: the reflection of the pleura onto the root of the lung to continue as mediastinal pleura.
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

Post-operative fever is very common.
It is known to occur after all types of surgical procedures, irrespective of the type of anaesthesia.
Postoperative fever can occur after minor surgical procedures but is rare and depends on the type of procedure. Overall, both abdominal and chest procedures result in the highest incidence of postoperative fever.

In this case:
Acute Fever
Fever occurs in the first week (1 to 7 POD)
POD 7 (5 to 10): Wound infection: Risk increases if the patient is immunocompromised (e.g., diabetic), abdominal wound, duration of surgery greater than 2 hours or contamination during surgery. Signs include erythema, warmth, tenderness, discharge.
Rule out abscess or collections by physical exam plus ultrasound if needed. If an abscess is present, drainage and antibiotics are needed. Prevention is by careful surgical technique and prophylactic antibiotics (e.g., intravenous cefazolin at the time of induction of anaesthesia as well as postoperatively if needed)

Other causes of Postoperative fever:
An Immediate Fever
Fever occurs immediately after surgery or within hours on postoperative days (POD) 0 or 1.
– Malignant hyperthermia: high-grade fever (greater than 40 C), occurs shortly after inhalational anaesthetics or muscle relaxant (e.g., halothane or succinylcholine), may have a family history of death after anaesthesia. Laboratory studies will reveal with metabolic acidosis and hypercalcemia. If not readily recognized, it can cause cardiac arrest. The treatment is intravenous dantrolene, 100% oxygen, correction of acidosis, cooling blankets, and watching for myoglobinuria.
– Bacteraemia: High-grade fever (greater than 40 C) occurring 30 to 40 minutes after the beginning of the procedure (e.g., Urinary tract instrumentation in the presence of infected urine). Management includes blood cultures three times and starting empiric antibiotics.
– Gas gangrene of the wound: High-grade fever (greater than 40 C) occurring after gastrointestinal (GI) surgery due to contamination with Clostridium perfringens; severe wound pain; treat with surgical debridement and antibiotics.
– Febrile non-haemolytic transfusion reaction: Fevers, chills, and malaise 1 to 6 hours after surgery (without haemolysis). Management: Stop transfusion (rule out haemolytic transfusion reaction) and give antipyretics (avoid aspirin in the thrombocytopenic patient).

B. Acute Fever
– Fever occurs in the first week (1 to 7 POD).
POD 1 to 3: atelectasis: After prolonged intubation, the presence of upper abdominal incision, inadequate postoperative pain control, lying supine. Should be prevented by incentive spirometry, semi-recumbent position, adequate pain control, early ambulation. Clinically may be asymptomatic or with increased work of breathing, respiratory alkalosis, chest x-ray with volume loss. Treatment includes spirometry, chest physiotherapy, semi-recumbent position (improves expansion of alveoli by preventing pressure from intra-abdominal organs on the diaphragm and hence improving functional residual capacity)
– POD 3: Unresolved atelectasis resulting in pneumonia (respiratory symptoms, Chest x-ray with infiltrate or consolidation, sputum culture, empiric antibiotics and modify according to culture result and sensitivity), or development of urinary tract infection (urine analysis and culture, treat with empiric antibiotics and modify according to culture result and sensitivity)
– POD 5: Thrombophlebitis (may be asymptomatic or symptomatic, diagnose with Doppler ultrasound of deep leg and pelvic veins and treat with heparin)
– POD 7: Pulmonary embolism (tachycardia, tachypnoea, pleuritic chest pain, ECG with right heart strain pattern (a low central venous pressure goes against diagnosis), arterial blood gas with hypoxemia and hypocapnia, confirm diagnosis with CT angiogram, and treat with heparin, if recurrent pulmonary embolism while anticoagulated with therapeutic INR, Inferior vena cava filter placement is the next step

C. Subacute Fever
Fever occurs between postoperative weeks 1 and 4.
– POD 10: Deep infection (pelvic or abdominal abscess and if abdominal abscess could be sub-hepatic or sub-phrenic). A digital rectal exam to rule out the pelvic abscess and CT scan to localize intra-abdominal abscess. Treatment includes re-exploration vs. radiological guided percutaneous drainage
Drugs: Diagnosis of exclusion includes rash and peripheral eosinophilia

D. Delayed Fever
Fever after more than 4 weeks.
Skin and soft tissue infections (SSTI)
Viral infections

Tobacco smoking is the main known contributor to urinary bladder cancer. In most populations, smoking is associated with over half of bladder cancer cases in men and one-third of cases among women.

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.

Paget’s disease of bone (PDB) is a focal disorder of bone. It is presumed benign in nature and mediated by abnormal osteoclast function. However osteosarcomas may occur in <1% of patients with Paget's disease of the bone. Osteosarcomas are osteogenic in origin, and consistently arise in sites of pagetic bone. This is not to be confused with Paget's disease of the breast.

Medullary carcinoma of thyroid accounts for 3% of thyroid cancers. It arises from the parafollicular cells (C cells) of the thyroid gland that produce calcitonin. It is often familial and caused by mutation of ret proto-oncogene, but can occasionally be sporadic. The familial cases can also occur as part of MEN syndromes IIA and IIB. The high calcitonin leads to down-regulation of the receptors, which does not affect the calcium levels significantly. Medullary carcinoma of thyroid shows characteristic amyloid deposits that stain positively with Congo red. The initial presentation consists of an asymptomatic thyroid nodule. Many cases are diagnosed due to routine screening of relatives of patients with MEN IIA and IIB. Medullary carcinoma can also cause ectopic production of other hormones/peptides such as adrenocorticotrophic hormone, vasoactive intestinal polypeptide, kallikreins and serotonin.
Metastasis from medullary carcinoma spread via the lymphatics to cervical and mediastinal nodes, and can also affect the liver, lungs and bone. Diagnosis is by raised serum calcitonin levels. A provocative test with calcium (15 mg/kg intravenously over 4 hours) also aids in diagnosis by leading to excessive secretion of calcitonin. X-ray might also show dense, conglomerate calcification.
CA-125 is frequently elevated in ovarian carcinomas. CA 15-3 is often associated with breast carcinomas. Alpha-fetoprotein is seen raised in hepatomas and gonadal tumours. Elevated HCG is associated with normal pregnancies, gonadal tumours, and choriocarcinomas. Thyroglobulin is used for surveillance in papillary carcinoma of thyroid. CA 19-9 is used in the management of pancreatic cancer.

The inferior mesenteric artery supplies blood to the end of the transverse colon and all distal structures in the gastrointestinal tract i.e. splenic flexure, descending colon, sigmoid colon and rectum would all be deprived of blood if it were occluded. The caecum receives blood from the superior mesenteric artery so it would not be affected.

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.

The blood–brain barrier is a membrane that controls the passage of substances from the blood into the central nervous system. It is a physical barrier between the local blood vessels and most parts of the central nervous system and stops many substances from travelling across it. During meningitis, the blood–brain barrier may be disrupted. This disruption may increase the penetration of various substances (including either toxins or antibiotics) into the brain. A few regions in the brain, including the circumventricular organs, do not have a blood–brain barrier.

Latissimus dorsi is a triangular, flat muscle that covers the lumbar region and the lower half of the thoracic region. It is supplied by the sixth, seventh and eighth cervical nerves through the thoracodorsal (long subscapular) nerve.

Tyrosine is the precursor to adrenaline, noradrenaline and dopamine. Tyrosine hydroxylase converts tyrosine to DOPA, which is in turn converted to dopamine, then to noradrenaline and finally adrenaline.

The rough endoplasmic reticulum is the factory for the manufacturing of proteins. It contains ribosomes attached to it and transports proteins that are destined for membranes and secretions. The rough ER is connected to the nuclear envelope and to the cisternae of the Golgi apparatus by vesicles that shuttle between the two compartments.

Colonic injuries that are managed with resection are associated with a high complication rate regardless of whether an anastomosis or colostomy is performed. Colonic resection and anastomosis can be performed safely in the majority of patients with severe colonic injury, including injuries to the left colon. For injuries of the right colon, an ileocolostomy has a lower incidence of leakage than a colocolonic anastomosis. For injuries to the left colon, there remains a role for colostomy specifically in the subgroups of patients with a high ATI or hypotension, because these patients are at greater risk for an anastomotic leak. The role of resection and primary anastomosis versus colostomy in colonic trauma requires further investigation.

The oculomotor nerve is the third cranial nerve (CNIII). It offers motor and parasympathetic innervation to many of the ocular structures. The motor fibres innervate a number of the extraocular muscles. While the parasympathetic fibres supply the sphincter pupillae and the ciliary muscles of the eye, and the sympathetic fibres innervates the superior tarsal muscles.

Answer: Escharotomy

Escharotomy is the surgical division of the nonviable eschar, which allows the cutaneous envelope to become more compliant. Hence, the underlying tissues have an increased available volume to expand into, preventing further tissue injury or functional compromise.

Full-thickness circumferential and near-circumferential skin burns result in the formation of a tough, inelastic mass of burnt tissue (eschar). The eschar, by virtue of this inelasticity, results in the burn-induced compartment syndrome. This is caused by the accumulation of extracellular and extravascular fluid within confined anatomic spaces of the extremities or digits. The excessive fluid causes the intracompartmental pressures to increase, resulting in collapse of the contained vascular and lymphatic structures and, hence, loss of tissue viability. The capillary closure pressure of 30 mm Hg, also measured as the compartment pressure, is accepted as that which requires intervention to prevent tissue death.

The circumferential eschar over the torso can lead to significant compromise of chest wall excursions and can hinder ventilation. Abdominal compartment syndrome with visceral hypoperfusion is associated with severe burns of the abdomen and torso. (A literature review by Strang et al found the prevalence of abdominal compartment syndrome in severely burned patients to be 4.1-16.6%, with the mean mortality rate for this condition in these patients to be 74.8%). Similarly, airway patency and venous return may be compromised by circumferential burns involving the neck.

Containment of fistula output and skin protection should be instituted as soon as the diagnosis is made as it will decrease local skin excoriation and inflammation, pain and infection. While low output fistulas may be controlled with a simple absorbent dressing, complex fistulas often require advanced techniques including barrier creams, powders, and sealants to protect the skin from auto-digestion as well as bridging for fistula isolation, topographical enhancements, and complex pouching systems with or without sump drainage
Fistulas arising from the oesophagus, duodenal stump after gastric resection, pancreaticobiliary tract, and jejunum are more likely to close without operative intervention. Additionally, those with long tracts and small enteric wall defects are associated with higher spontaneous closure rates. Fistulas in the colon show favourable rates of spontaneous resolution.

The moderator band extends from the base of the anterior papillary muscle to the ventricular septum. It is the structure which carries part of the right AV bundle. Its role it to prevent overdistention of the ventricle.

Haemoglobin S is an abnormal type of haemoglobin seen in sickle cell anaemia. This allows for the haemoglobin to crystalize within the RBC upon exposure to low partial pressures of oxygen. This results in rupture of the RBCs as they pass through microcirculation, especially in the spleen. This can cause blockage of the vessel down stream and ischaemic death of tissues, accompanied by severe pain.

The petrous segment, or C2, of the internal carotid is that which is inside the petrous part of the temporal bone. This segment extends until the foramen lacerum. The petrous portion classically has three sections: an ascending, or vertical portion; the genu, or bend; and the horizontal portion.

Reversal of the central effects of midazolam by intravenous flumazenil after general anaesthesia. Since many benzodiazepines have longer half lives than flumazenil patients still require close monitoring after receiving the drug. Other drugs provided in the options would not characteristically be used for the reversal of midazolam.

Aflatoxins are naturally occurring toxins produced by the Aspergillus fungus (most often, A. flavus and A. parasiticus). These organisms are common and their native habitat is soil, decaying vegetation and grains. They can contaminate the grain before harvest or after storage, more likely in high-humidity (at least 7%) or high temperature environment of after stressful conditions like drought. Aflatoxins are mycotoxins and also carcinogenic. They get metabolized in the liver to an epoxide, aflatoxin M1. High exposure can lead to acute necrosis, cirrhosis or liver carcinoma. These substances can cause haemorrhage, acute liver damage, oedema, and alteration in digestion, absorption and/or metabolism of nutrients. Although humans are susceptible to these toxins like all other animals, they have a high tolerance level and hence, rarely develop acute aflatoxicosis. However, children are particularly susceptible to exposure leading to growth impairment and delayed development. Chronic exposure carries a high risk of hepatic cancer, due to intercalation of its metabolite aflatoxin M1 into the DNA and alkylation of the bases because of its epoxide moiety.

Answer: It may result in metabolic complications such a refeeding syndrome, resulting in hyperkalaemia, hypermagnesemia, and hyperphosphatemia.

Refeeding syndrome can be defined as the potentially fatal shifts in fluids and electrolytes that may occur in malnourished patients receiving artificial refeeding (whether enterally or parenterally. These shifts result from hormonal and metabolic changes and may cause serious clinical complications. The hallmark biochemical feature of refeeding syndrome is hypophosphatemia. However, the syndrome is complex and may also feature abnormal sodium and fluid balance; changes in glucose, protein, and fat metabolism; thiamine deficiency; hypokalaemia; and hypomagnesaemia.
During refeeding, glycaemia leads to increased insulin and decreased secretion of glucagon. Insulin stimulates glycogen, fat, and protein synthesis. This process requires minerals such as phosphate and magnesium and cofactors such as thiamine. Insulin stimulates the absorption of potassium into the cells through the sodium-potassium ATPase symporter, which also transports glucose into the cells. Magnesium and phosphate are also taken up into the cells. Water follows by osmosis. These processes result in a decrease in the serum levels of phosphate, potassium, and magnesium, all of which are already depleted. The clinical features of the refeeding syndrome occur as a result of the functional deficits of these electrolytes and the rapid change in basal metabolic rate.

This may be a case of malignant melanoma. Excision biopsy is required to allow accurate histological assessment. If the diagnosis is confirmed, re-excision of margins may be required. Incisional or punch biopsy of lesions suspected to be melanoma is avoided.

Various options used for the treatment of skin lesions include:
1. Trucut biopsy
2. Punch biopsy
3. Excision biopsy
4. Wide excision biopsy
5. Incisional biopsy

The most common predisposing factor leading to acute tubular necrosis is ischemia, typically seen in hospitalized patients with low blood pressure.

In performing noncardiac surgery on patients on anticoagulation, the major concern is when it is safe to perform surgery without increasing the risk of haemorrhage or increasing the risk of thromboembolism (e.g., venous, arterial) after discontinuing treatment.
Any patient who is on long-term anticoagulation and is to undergo a major surgery needs proactive management.
Heparin is discontinued 6-12 hours before surgery and restarted at 200-400 U/h at 4-6 hours after surgery. Coumadin is restarted as soon as tolerated by the patient. Stop oral anticoagulants at least 5 days preoperatively, and do not perform the procedure until the PT is in the reference range.

Branches that stem from the abdominal aorta can be divided into three: the visceral branches, parietal branches and terminal branches. Of the visceral branches, the suprarenal, renal, testicular and ovarian arteries are paired while the coeliac artery and superior and inferior mesenteric arteries are unpaired. Of the parietal branches the inferior phrenic and lumbar arteries are paired while the middle sacral artery is unpaired. The terminal branches i.e. the common iliac arteries are paired.

Streptococcus bovis (S. bovis) bacteria are associated with colorectal cancer and adenoma. S. bovis is currently named S. gallolyticus. 25-80% of patients with S. bovis/gallolyticus bacteraemia have concomitant colorectal tumours. Colonic neoplasia may arise years after the presentation of bacteraemia or infectious endocarditis of S. bovis/gallolyticus. The presence of S. bovis/gallolyticus bacteraemia and/or endocarditis is also related to the presence of villous or tubular-villous adenomas in the large intestine.

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.