29- Pathology Explains 1 Flashcards
What does the Dukes classification system determine?
The Dukes classification system determines the extent of spread of colorectal cancer.
What does Dukes A indicate?
Dukes A indicates that the tumor is confined to the bowel without extending beyond it, and there are no nodal metastases. This accounts for approximately 95% of cases.
What does Dukes B indicate?
Dukes B indicates that the tumor has invaded the bowel wall but there are no nodal metastases. This accounts for approximately 75% of cases.
What does Dukes C indicate?
Dukes C indicates the presence of lymph node metastases. This accounts for approximately 50% of cases.
What does Dukes D indicate?
Dukes D indicates the presence of distant metastases. This accounts for approximately 6% of cases (25% if the metastases are resectable).
Who is stereotypically affected by primary hyperparathyroidism?
Primary hyperparathyroidism is stereotypically seen in elderly females.
What are common symptoms of primary hyperparathyroidism?
Common symptoms include unquenchable thirst, an inappropriately normal or raised parathyroid hormone level, and it is most commonly due to a solitary adenoma.
What are the causes of primary hyperparathyroidism?
The causes of primary hyperparathyroidism are: 80% solitary adenoma, 15% hyperplasia, 4% multiple adenoma, and 1% carcinoma.
What are the features associated with primary hyperparathyroidism?
The features associated with primary hyperparathyroidism are often remembered by the phrase ‘bones, stones, abdominal groans, and psychic moans.’ These include polydipsia and polyuria, peptic ulceration, constipation, pancreatitis, bone pain/fracture, renal stones, and depression.
What are the associations of primary hyperparathyroidism?
Associations include hypertension and multiple endocrine neoplasia (MEN I and II).
What are the typical findings on investigations for primary hyperparathyroidism?
Typical findings on investigations include raised calcium levels, low phosphate levels, and the possibility of a raised or normal parathyroid hormone (PTH) level. A technetium-MIBI subtraction scan may also be performed.
What is the treatment for primary hyperparathyroidism?
The treatment for primary hyperparathyroidism is parathyroidectomy. If imaging suggests a target gland, a focused approach may be used.
What are the characteristics of adenomas that correlate with malignant potential?
Three characteristics of adenomas that correlate with malignant potential are increased size, villous architecture, and dysplasia.
What are the different types of polyps seen in colorectal cancer?
Polyps can be categorized as neoplastic polyps, adenomatous polyps, and non-neoplastic polyps.
What genetic changes accompany the transition from adenoma to carcinoma?
Genetic changes that accompany the transition from adenoma to carcinoma include APC, c-myc, K RAS mutations, and p53 deletions.
What is the transformation process from polyp to cancer called?
The transformation from polyp to cancer is described by the adenoma-carcinoma sequence.
What are some examples of non-neoplastic polyps?
Non-neoplastic polyps include hyperplastic, juvenile, hamartomatous, inflammatory, and lymphoid polyps.
Why should most polyps identified at colonoscopy be removed?
Most polyps identified at colonoscopy should be removed because they may have malignant potential.
What is the most common type of oesophageal cancer in the Western world?
In the Western world, the most common type of oesophageal cancer is adenocarcinoma.
What is a major risk factor for oesophageal adenocarcinoma?
Barrett’s oesophagus is a major risk factor for most cases of oesophageal adenocarcinoma.
What are some risk factors for squamous cell oesophageal cancer?
In other regions of the world, squamous cell oesophageal cancer is more common and is linked to smoking, alcohol intake, diets rich in nitrosamines, and achalasia.
Why is surveillance of Barrett’s oesophagus important?
Surveillance of Barrett’s oesophagus is important because it imparts a 30-fold increase in cancer risk. Early diagnosis of invasive malignancy may lead to a 5-year survival rate of approximately 85%.
What is the first-line test for the diagnosis of oesophageal cancer?
Upper GI endoscopy is the first-line test for the diagnosis of oesophageal cancer.
What imaging modality is used for staging oesophageal cancer?
CT scanning of the chest, abdomen, and pelvis is used for staging oesophageal cancer.
What surgical procedure is commonly performed for operable oesophageal cancer?
The most standard surgical procedure for operable oesophageal cancer is an Ivor-Lewis type oesophagectomy.
What is the biggest surgical challenge in oesophageal cancer surgery?
The biggest surgical challenge is anastomotic leak, which can result in complications such as mediastinitis.
Are patients with oesophageal cancer commonly treated with adjuvant chemotherapy?
Yes, many patients with oesophageal cancer will be treated with adjuvant chemotherapy in addition to surgical resection.
What are the risk factors for pancreatic adenocarcinoma?
The risk factors for pancreatic adenocarcinoma include smoking, diabetes, adenoma, and familial adenomatous polyposis.
In which part of the pancreas does pancreatic adenocarcinoma mainly occur?
Pancreatic adenocarcinoma mainly occurs in the head of the pancreas (70%).
Why is it important to differentiate carcinoma of the pancreas from other periampullary tumors?
It is important to differentiate carcinoma of the pancreas from other periampullary tumors because pancreatic carcinoma has a worse prognosis.
Where does pancreatic adenocarcinoma commonly metastasize to?
Pancreatic adenocarcinoma commonly metastasizes to the liver and spreads locally.
What are the clinical features of pancreatic cancer?
The clinical features of pancreatic cancer include weight loss, painless jaundice, epigastric discomfort, pancreatitis, and Trousseau’s sign (migratory superficial thrombophlebitis).
What is the surgical management for pancreatic cancer in the head of the pancreas?
Whipple’s resection is the surgical management for pancreatic cancer in the head of the pancreas.
What imaging modality is recommended for pancreatic cancer staging?
CT scanning (pancreatic protocol) is recommended for pancreatic cancer staging.
When is staging laparoscopy performed for pancreatic cancer?
Staging laparoscopy is performed to exclude peritoneal disease in pancreatic cancer.
What surgical procedure is performed for carcinoma in the body and tail of the pancreas?
For carcinoma in the body and tail of the pancreas, distal pancreatectomy is performed.
What is the usual treatment for resectable pancreatic cancer?
Resectable pancreatic cancer is usually treated with adjuvant chemotherapy.
What are oncoviruses?
Oncoviruses are viruses that can cause cancer.
Can oncoviruses be detected through a blood test?
Yes, oncoviruses can be detected through a blood test.
How can oncovirus-related cancers be prevented?
Oncovirus-related cancers can be prevented through vaccination.
Which oncovirus is associated with Burkitt’s lymphoma, Hodgkin’s lymphoma, post-transplant lymphoma, and nasopharyngeal carcinoma?
The Epstein-Barr virus is associated with these cancers.
Which oncovirus is associated with cervical cancer, anal cancer, penile cancer, vulval cancer, and oropharyngeal cancer?
Human papillomavirus 16/18 is associated with these cancers.
Which oncovirus is associated with Kaposi’s sarcoma?
Human herpes virus 8 is associated with Kaposi’s sarcoma.
Which oncovirus is associated with hepatocellular carcinoma?
Hepatitis B virus and hepatitis C virus are associated with hepatocellular carcinoma.
Which oncovirus is associated with tropical spastic paraparesis and adult T cell leukaemia?
Human T-lymphotropic virus 1 is associated with these conditions.
What is Paget’s disease?
Paget’s disease is a disease characterized by increased and uncontrolled bone turnover, resulting in architecturally abnormal bones.
Which cells are primarily involved in Paget’s disease?
Osteoclasts are primarily involved in Paget’s disease, leading to excessive bone resorption followed by increased osteoblastic activity.
What are the predisposing factors for Paget’s disease?
The predisposing factors for Paget’s disease include increasing age, male sex, living in northern latitudes, and having a family history of the disease.
What are the clinical features of Paget’s disease?
The clinical features of Paget’s disease include bone pain (e.g., pelvis, lumbar spine, femur), bowing of the tibia, bossing of the skull, and elevated alkaline phosphatase levels.
What are the indications for treatment in Paget’s disease?
Indications for treatment in Paget’s disease include bone pain, skull or long bone deformity, fractures, and periarticular involvement.
What are the commonly used treatments for Paget’s disease?
The commonly used treatments for Paget’s disease are bisphosphonates (oral risedronate or IV zoledronate). Calcitonin is less commonly used now.
What are the complications associated with Paget’s disease?
Complications of Paget’s disease include deafness (cranial nerve entrapment), bone sarcoma (1% if affected for > 10 years), fractures, skull thickening, and high-output cardiac failure.
What is the typical presentation of the skull on x-ray in Paget’s disease?
On x-ray, Paget’s disease of the skull may show a thickened vault and osteoporosis circumscripta.
Are calcium and phosphate levels typically affected in Paget’s disease?
No, calcium and phosphate levels are typically normal in Paget’s disease, although hypercalcemia may occur with prolonged immobilization.
What are the main processes that can lead to chronic inflammation?
The main processes that can lead to chronic inflammation include persisting infection with certain organisms (such as Mycobacterium tuberculosis), prolonged exposure to non-biodegradable substances (like silica or suture materials), and autoimmune conditions involving antibodies formed against host antigens.
What are the key differences between acute inflammation and chronic inflammation?
Acute inflammation involves changes to vascular structure, increased permeability of endothelial cells, and infiltration of neutrophils. It can resolve with suppuration, complete resolution, abscess formation, or progress to chronic inflammation. Chronic inflammation is characterized by angiogenesis, predominance of macrophages, plasma cells, and lymphocytes, and healing by fibrosis.
What is granulomatous inflammation?
Granulomatous inflammation is a type of chronic inflammation characterized by the formation of granulomas. Granulomas consist of a microscopic aggregation of macrophages, with epithelioid arrangement, and may have large giant cells at the periphery.
What are some mediators released by activated macrophages in chronic inflammation?
Some mediators released by activated macrophages in chronic inflammation include interferon, fibroblast growth factor, and other growth factors. These mediators can have systemic effects, leading to systemic symptoms and signs in individuals with long-standing chronic inflammation.
What is the significance of finding granulomas in the context of chronic inflammation?
The finding of granulomas is pathognomonic of chronic inflammation. Granulomas are characteristic microscopic structures seen in conditions such as colonic Crohn’s disease.
What are the main causes of hypercalcemia?
The main causes of hypercalcemia include malignancy (most common in hospital in-patients) and primary hyperparathyroidism (commonest cause in non-hospitalized patients).
What are some less common causes of hypercalcemia?
Less common causes of hypercalcemia include sarcoidosis (extrarenal synthesis of calcitriol), thiazides, lithium, immobilization, Paget’s disease, vitamin A/D toxicity, thyrotoxicosis, MEN (multiple endocrine neoplasia), and milk alkali syndrome.
What are the clinical features of hypercalcemia?
The clinical features of hypercalcemia are often summarized as “stones, bones, abdominal groans, and psychic moans.” This refers to the potential occurrence of kidney stones, bone pain or fractures, abdominal discomfort, and mood or mental changes.
How does high serum calcium levels affect neuronal excitability?
High serum calcium levels result in decreased neuronal excitability. As a result, individuals with hypercalcemia may experience sluggish reflexes, muscle weakness, and constipation.
What is the role of Helicobacter pylori in ulceration?
Helicobacter pylori infection is implicated in many cases of duodenal ulceration and up to 60% of patients with gastric ulceration.
Describe the characteristics of Helicobacter pylori.
Helicobacter pylori is a gram-negative, helical-shaped rod with microaerophilic requirements. It produces a urease enzyme that hydrolyzes urea, resulting in the production of ammonia.
How does ammonia affect the release of gastrin?
Ammonia, produced by Helicobacter pylori, stimulates the release of gastrin from antral G cells via a negative feedback loop.
What are the effects of Helicobacter pylori infection on the gastric mucous layer?
Once infection is established, Helicobacter pylori releases enzymes that disrupt the gastric mucous layer, leading to chronic inflammation of the gastric epithelium and the development of gastric ulcers.
What is the role of Helicobacter pylori in duodenal ulceration?
Although Helicobacter pylori cannot colonize the duodenal mucosa, it can induce a process of duodenal gastric metaplasia, where the duodenal mucosa changes to the gastric epithelial type. This metaplastic tissue can be colonized by Helicobacter pylori, leading to inflammation, duodenitis, and ulcers.
What are the risks associated with Helicobacter pylori colonization?
In patients who are colonized by Helicobacter pylori, there is a 10-20% risk of peptic ulcer, a 1-2% risk of gastric cancer, and a less than 1% risk of MALT lymphoma.
What is in situ disease in breast cancer?
In situ disease in breast cancer refers to cancer that has not yet invaded the basement membrane.
What are the subtypes of ductal carcinoma in situ (DCIS)?
The subtypes of DCIS include comedo, cribriform, micropapillary, and solid.
Which subtype of DCIS is most likely to form microcalcifications?
Comedo DCIS is most likely to form microcalcifications.
Which subtypes of DCIS are most likely to be multifocal?
Cribriform and micropapillary subtypes of DCIS are most likely to be multifocal.
What is the usual treatment approach for low nuclear grade DCIS?
Local excision of low nuclear grade DCIS typically produces satisfactory outcomes.
Are most DCIS lesions composed of a single subtype or multiple subtypes?
Most DCIS lesions are mixed and composed of multiple subtypes.
What is the association between high nuclear grade DCIS and malignant characteristics?
High nuclear grade DCIS is associated with more malignant characteristics, such as loss of p53 and increased erbB2 expression.
When is mastectomy usually required for DCIS?
Mastectomy is usually required for multifocal lesions, large lesions, and high nuclear grade lesions of DCIS.
How does lobular carcinoma in situ (LCIS) differ from DCIS?
LCIS is much rarer than DCIS and does not form microcalcifications. It usually has a single growth pattern and is often monitored rather than excised when it is low grade.
What is the benefit of whole breast irradiation in breast-conserving surgery for DCIS?
Whole breast irradiation improves locoregional control when breast-conserving surgery is performed for DCIS.
What is the difference in axillary nodal metastasis between LCIS and invasive foci found within DCIS?
When an invasive component is found in LCIS, it is less likely to be associated with axillary nodal metastasis than invasive foci found within DCIS.
Where is the spleen located?
The spleen is located in the left upper quadrant of the abdomen.
What are the typical dimensions of the adult spleen?
The typical adult spleen is 12.5cm long and 7.5cm wide.
Is the normal spleen palpable?
No, the normal spleen is not palpable.
What is the usual weight of the adult spleen?
The usual weight of the adult spleen is 150g.
What covers the spleen and adheres firmly to its capsule?
The spleen is almost entirely covered by peritoneum, which adheres firmly to its capsule.
How does the shape of the spleen change with gastric and colonic distension?
Gastric distension causes the spleen to resemble the shape of an orange segment, while colonic distension makes it more tetrahedral.
What ligaments connect the spleen to the posterior abdominal wall and stomach?
The spleen is connected to the posterior abdominal wall and stomach by two folds of peritoneum: the lienorenal ligament and gastrosplenic ligament.
What are the relations of the spleen?
Superiorly, it is related to the diaphragm. Anteriorly, it has a gastric impression. Posteriorly, it is related to the kidney. Inferiorly, it is related to the colon.
What structures are found at the hilum of the spleen?
At the hilum, you can find the tail of the pancreas and splenic vessels. The splenic artery divides here, and its branches pass to the white pulp, transporting plasma.
What is the function of the white pulp in the spleen?
The white pulp of the spleen has immune function. It contains a central trabecular artery and germinal centers supplied by penicilliary radicles.
What is the function of the red pulp in the spleen?
The red pulp of the spleen filters abnormal red blood cells and foreign bodies, such as bacteria.
What are the functions of the spleen?
The spleen functions in the filtration of abnormal blood cells and foreign bodies, immunity (IgM production, properdin, and tuftsin), haematopoiesis (up to the 5th month of gestation or in haematological disorders), platelet storage (40% storage), iron reutilization, and storage of monocytes.
What are some disorders of the spleen?
Disorders of the spleen include massive splenomegaly, myelofibrosis, chronic myeloid leukemia, visceral leishmaniasis (kala-azar), malaria, Gaucher’s syndrome, portal hypertension (secondary to cirrhosis), lymphoproliferative disease (e.g., CLL, Hodgkin’s), haemolytic anemia, infection (hepatitis, glandular fever, infective endocarditis), sickle-cell disease (majority of adult patients have an atrophied spleen due to repeated infarction), and rheumatoid arthritis (Felty’s syndrome).
Where are hydatid cysts endemic?
Hydatid cysts are endemic in Mediterranean and Middle Eastern countries.
What causes hydatid cysts?
Hydatid cysts are caused by the tapeworm parasite Echinococcus granulosus.
What is the composition of hydatid cysts?
Hydatid cysts have an outer fibrous capsule containing multiple small daughter cysts.
What type of hypersensitivity reaction do hydatid cysts precipitate?
Hydatid cysts precipitate a type 1 hypersensitivity reaction due to the allergens they contain.
Where do up to 90% of hydatid cysts occur?
Up to 90% of hydatid cysts occur in the liver and lungs.
When do hydatid cysts become symptomatic?
Hydatid cysts can be asymptomatic, but become symptomatic if they are larger than 5cm in diameter.
What are the potential complications of hydatid cysts?
Complications of hydatid cysts include cyst bursting, infection, and organ dysfunction (such as biliary, bronchial, renal, and cerebrospinal fluid outflow obstruction).
What is the classical triad seen in biliary rupture of hydatid cysts?
The classical triad seen in biliary rupture of hydatid cysts includes biliary colic, jaundice, and urticaria.
What does PSA stand for?
PSA stands for prostate specific antigen.
Which imaging modality is best for differentiating hydatid cysts from other types of cysts?
CT (computed tomography) is the best investigation for differentiating hydatid cysts from amoebic and pyogenic cysts.
What is the mainstay of treatment for hydatid cysts?
Surgery is the mainstay of treatment for hydatid cysts. During removal, the cyst walls must not be ruptured, and the contents must be sterilized first.
Which cells produce PSA?
PSA is produced by both normal and malignant prostate epithelial cells.
Is PSA testing widely accepted as a screening tool for prostate cancer?
There is controversy surrounding the usefulness of PSA testing as a screening tool for prostate cancer.
What did the European trial (ERSPC) find regarding the rate of death from prostate cancer?
The ERSPC trial showed a statistically significant 20% reduction in the rate of death from prostate cancer in men aged 55 to 69 years.
What did the NHS Prostate Cancer Risk Management Programme (PCRMP) publish in 2009?
The PCRMP published guidelines on how to handle requests for PSA testing in asymptomatic men.
Has a prostate cancer screening program been introduced by the National Screening Committee?
No, the National Screening Committee has decided not to introduce a prostate cancer screening program yet.
What are the age-adjusted upper limits for PSA recommended by the PCRMP?
Age-adjusted upper limits for PSA are as follows: 3.0 ng/ml for ages 50-59, 4.0 ng/ml for ages 60-69, and 5.0 ng/ml for ages >70.
What are some factors that can raise PSA levels?
Factors that can raise PSA levels include benign prostatic hyperplasia (BPH), prostatitis and urinary tract infection, ejaculation (within 48 hours), vigorous exercise (within 48 hours), urinary retention, and instrumentation of the urinary tract.
What is the specificity and sensitivity of PSA testing for prostate cancer?
PSA testing has poor specificity and sensitivity. Around 33% of men with a PSA of 4-10 ng/ml will be found to have prostate cancer, and around 20% of men with prostate cancer have a normal PSA.
What methods are used to add greater meaning to a PSA level?
Age-adjusted upper limits and monitoring changes in PSA level over time (PSA velocity or PSA doubling time) are used to add greater meaning to a PSA level.
What is the most common benign tumor of mesenchymal origin in the liver?
Haemangioma
What is the incidence of haemangiomas in autopsy series?
8%
How do haemangiomas appear clinically?
They appear as reddish-purple hypervascular lesions.
How are haemangiomas typically separated from normal liver tissue?
They are separated by a ring of fibrous tissue.
What is the typical ultrasound appearance of haemangiomas?
They are typically hyperechoic on ultrasound.
Which demographic is most commonly affected by liver cell adenomas?
90% of liver cell adenomas develop in women in their third to fifth decade.
What is liver cell adenoma associated with?
Liver cell adenoma is associated with the use of oral contraceptive pills.
How do liver cell adenomas usually appear on imaging?
Liver cell adenomas usually have mixed echoity and heterogeneous texture on ultrasound, and most lesions are hypodense on CT prior to administration of IV contrast agents.
When may removal of the adenoma be required?
In cases of hemorrhage or symptoms, removal of the adenoma may be necessary.
What is the typical presentation of mesenchymal hamartomas?
Mesenchymal hamartomas are congenital and benign, usually present in infants, and may compress normal liver tissue.
What is a major predisposing factor for liver abscess?
Biliary sepsis is a major predisposing factor for liver abscess.
What structures contribute to the second largest source of liver abscesses?
Structures drained by the portal venous system contribute to the second largest source of liver abscesses.
What are common symptoms of liver abscess?
Common symptoms include fever and right upper quadrant pain, with jaundice seen in 50% of cases.
What is the typical ultrasound appearance of liver abscesses?
Ultrasound typically shows a fluid-filled cavity, with hyperechoic walls seen in chronic abscesses.
What is the most common extra-intestinal manifestation of amoebiasis?
Liver abscess is the most common extra-intestinal manifestation of amoebiasis.
Where do the majority of amoebic abscesses occur within the liver?
Between 75 and 90% of amoebic abscesses occur in the right lobe of the liver.
What are the typical presenting complaints of amoebic abscess?
Typical presenting complaints include fever and right upper quadrant pain.
What does ultrasonography usually show in the case of amoebic abscess?
Ultrasonography usually shows a fluid-filled structure with poorly defined boundaries.
What is the treatment for amoebic abscess?
Treatment is with metronidazole.
In what cases are hydatid cysts seen?
Hydatid cysts are seen in cases of Echinococcus infection.
What is the typical presentation of hydatid cysts?
Hydatid cysts typically present with malaise and right upper quadrant pain. Secondary bacterial infection occurs in 10% of cases.
What do liver function tests and eosinophilia show in the case of hydatid cysts?
Liver function tests are usually abnormal and eosinophilia is present in 33% of cases.
What may ultrasound show in the case of hydatid cysts?
Ultrasound may show septa and hydatid sand or daughter cysts.
What is the treatment for hydatid cysts?
Treatment involves sterilization of the cyst with mebendazole, followed by surgical resection in some cases.
With what condition is polycystic liver disease usually associated?
Polycystic liver disease usually occurs in association with polycystic kidney disease.
What is the typical symptom of polycystic liver disease?
Symptoms may occur as a result of capsular stretch.
What are cystadenomas?
Cystadenomas are rare lesions with malignant potential.
How do cystadenomas usually appear on imaging?
Cystadenomas typically appear as large anechoic, fluid-filled areas with irregular margins, and internal echoes may result from septa.
What is the recommended treatment for cystadenomas?
Surgical resection is indicated in all cases of cystadenomas.
What is mammary duct ectasia?
Dilation of the mammary ducts in the breast.
What percentage of normal female breasts may show mammary duct ectasia?
Up to 25%.
What is the common presentation of patients with duct ectasia?
Nipple discharge, usually from single or multiple ducts (typically in women over 50 years old).
What is the characteristic appearance of the discharge in duct ectasia?
Thick and green.
Is duct ectasia the same condition as periductal mastitis?
No, duct ectasia is a normal variant of breast involution, while periductal mastitis is a different condition.
How does periductal mastitis typically present?
It usually presents at a younger age than duct ectasia and may show signs of inflammation, abscess, or mammary duct fistula.
What is periductal mastitis strongly associated with?
Smoking.
How is periductal mastitis usually treated?
Typically with antibiotics, while an abscess may require drainage.
What is an intraductal papilloma?
A growth of papilloma within a single duct.
What is the typical presentation of intraductal papilloma?
Clear or blood-stained discharge originating from a single duct.
Does intraductal papilloma increase the risk of malignancy?
No, there is no increase in the risk of malignancy.
What is a common cause of breast abscess?
Lactational mastitis.
What is the usual causative organism in breast abscess?
Staphylococcus aureus.
How is breast abscess usually treated?
With antibiotics and ultrasound-guided aspiration.
What is the typical finding on examination in breast abscess?
A tender fluctuant mass.
What is an indication for surgical debridement in breast abscess?
Overlying skin necrosis.
Is tuberculosis of the breast common in western countries?
No, it is rare in western countries and usually occurs as secondary tuberculosis.
What is a common finding in cases of tuberculosis of the breast?
Chronic breast or axillary sinus is present in up to 50% of cases.
What complication may arise from surgical debridement of a breast abscess?
The development of a subsequent mammary duct fistula.
Which group of women does tuberculosis of the breast typically affect?
Women later in their childbearing period.
What vascular changes occur during inflammation?
Vasodilation and increased permeability of vessel walls.
How is tuberculosis of the breast diagnosed?
By biopsy culture and histology.
What is inflammation?
The tissue’s reaction to injury.
What important immunomodulatory function does the fibrin clot formed from the high fibrinogen content of the fluid serve?
It has several important immunomodulatory functions.
What disrupts the balance of Starling’s forces within capillary beds during inflammation?
The increased permeability of vessel walls, leading to the formation of a protein-rich exudate.
What happens to inflammatory cells during inflammation?
They exit the circulation and accumulate at the site of injury.
What are the possible sequelae of acute inflammation?
Resolution, organization, suppuration, or progression to chronic inflammation.
What occurs during organization of acute inflammation?
Delayed removal of exudate, leading to tissue organization and usually fibrosis.
What happens during resolution of acute inflammation?
The stimulus is removed, and normal tissue architecture is restored.
What happens during suppuration in acute inflammation?
Formation of an abscess or empyema.
When does progression to chronic inflammation usually occur?
When initial infection or suppuration has been inadequately managed.
What histological feature is characteristic of acute inflammation?
The presence of neutrophil polymorphs.
What type of inflammation is tuberculosis?
Primary chronic inflammation.
What causes tuberculosis?
The inability of macrophages to kill Mycobacterium tuberculosis.
What are some causes of acute inflammation?
Infections (viruses and bacteria), chemical agents, physical agents (trauma), hypersensitivity reactions, and tissue necrosis.
What is a Ghon complex?
The lung lesion plus affected lymph nodes in tuberculosis.
What is present in the center of a tuberculosis granuloma?
Caseous necrosis.
What is a granuloma?
A collection of epithelioid histiocytes formed in tuberculosis.
What type of hypersensitivity reaction mediates the inflammatory response in tuberculosis?
Type 4 hypersensitivity reaction.
What happens in healthy individuals with tuberculosis?
The disease may be contained.
What staining method is typically used to visualize Mycobacterium tuberculosis?
Ziehl-Neelsen staining.
What may occur in immunocompromised individuals with tuberculosis?
Disseminated tuberculosis, also known as miliary TB.
Why are culture-based methods for diagnosing tuberculosis time-consuming?
Because the waxy membrane of mycobacteria prevents binding with normal stains.
What is intraventricular hemorrhage (IVH)?
A hemorrhage that occurs into the ventricular system of the brain.
When is IVH relatively rare in adult surgical practice?
It is typically associated with severe head injuries.
When may IVH occur spontaneously?
In premature neonates.
What can happen to the blood in IVH?
It may clot and occlude cerebrospinal fluid (CSF) flow, leading to hydrocephalus.
When do the majority of IVH cases occur in neonatal practice?
Within the first 72 hours after birth.
What is the suggested cause of IVH in neonates?
Birth trauma combined with cellular hypoxia, due to the delicate neonatal central nervous system.
What is the recommended treatment for IVH?
Supportive care.
When is shunting indicated in IVH?
When there is hydrocephalus and rising intracranial pressure (ICP).
Have therapies such as intraventricular thrombolysis and prophylactic CSF drainage shown benefit in treating IVH?
No, they have not demonstrated benefit.
What type of disorder is Multiple Endocrine Neoplasia (MEN)?
An autosomal dominant disorder.
What are the three main types of MEN?
MEN type l, MEN type lla, and MEN type Ilb.
What gene is associated with MEN type l?
MENIN gene located on chromosome 11.
What are the main features of MEN type l?
Parathyroid adenoma, pituitary adenoma (prolactinoma/ACTH/growth hormone secreting adenoma), pancreatic islet cell tumors/Zollinger Ellison syndrome. Also adrenal and thyroid adenomas.
What is the most common presentation of MEN type l?
Hypercalcemia.
What additional features are seen in MEN type Ilb?
Marfanoid body habitus and mucosal neuromas.
What gene is associated with MEN type lla?
RET oncogene located on chromosome 10.
What gene is associated with MEN type Ilb?
RET oncogene located on chromosome 10.
What are the main features of MEN type lla?
Phaeochromocytoma, medullary thyroid cancer, and hyperparathyroidism.
What are the modalities of tissue sampling?
Fine needle aspiration cytology, core biopsy, excision biopsy, Tru cut biopsy, punch biopsy, cytological smears, and endoscopic or laparoscopic biopsy.
When is complete excision preferable in superficial lesions?
When safe margins are needed, such as in malignant melanoma.
When are punch biopsies useful?
In gaining histological diagnosis of unclear skin lesions where excision biopsy is undesirable, such as determining if a skin lesion is vasculitic or not.
What is fine needle aspiration cytology (FNAC)?
An operator-dependent procedure where a needle is passed through a lesion while suction is applied to a syringe, and the material obtained is expressed onto a slide for cytological assessment.
What can limit the usefulness of FNAC?
Operator inexperience and the lack of histological architectural information.
When may a sample be sent for cytology?
When a discharge is present, although the information obtained may be meaningless in certain sites such as nipple discharge.
What are core and Tru cut biopsies?
Methods of obtaining tissue samples using a spring-loaded gun or a needle moved by hand, respectively.
What should be considered during tissue sampling in preparation for surgical resection?
The need to potentially resect the biopsy tract along with the specimen, particularly in sarcoma surgery.
When might image guidance be desirable for core and Tru cut biopsies?
In cases such as breast lesions, where image guidance can assist in accurate sampling.
How can visceral lesions be accessed for sampling?
Percutaneously under image guidance, such as ultrasound-guided biopsy of liver metastases, or under direct vision, such as colonoscopic biopsy.
What are the features of Type A gastritis?
Autoimmune gastritis characterized by circulating antibodies to parietal cells, resulting in a reduction in cell mass and hypochlorhydria. It leads to the loss of intrinsic factor, causing B12 malabsorption. Antral involvement is absent, and hypochlorhydria leads to elevated gastrin levels and the potential formation of enterochromaffin cells and adenomas.
What are the features of Type B gastritis?
Antral gastritis associated with Helicobacter pylori infection. It may lead to intestinal metaplasia in the stomach, requiring surveillance endoscopy. Peptic ulceration can also occur.
What are the common causes of erosive gastritis?
Agents that disrupt the gastric mucosal barrier, such as NSAIDs and alcohol. NSAIDs induce these effects through COX-1 inhibition.
What causes reflux gastritis?
Bile reflux into the stomach, either due to post-surgical complications or failure of pyloric function. Histologically, it is characterized by chronic inflammation and foveolar hyperplasia. It may respond to therapy with prokinetics.
What causes stress ulceration?
Mucosal ischemia during hypotension or hypovolemia, particularly in the stomach, which is the most sensitive organ in the GI tract to ischemia following hypovolemia. It can lead to diffuse ulceration. Prophylaxis with acid-lowering therapy and sucralfate can minimize complications.
What are the characteristics of Menetrier’s disease?
Gross hypertrophy of the gastric mucosal folds, excessive mucous production, and hypochlorhydria. It is considered a premalignant condition.
What is the cause of Acute Intermittent Porphyria (AIP)?
A defect in porphobilinogen deaminase, an enzyme involved in the biosynthesis of heme.
What substances accumulate in AIP?
Delta aminolevulinic acid and porphobilinogen.
What are the common symptoms of AIP?
Abdominal pain, vomiting, motor neuropathy, and psychiatric symptoms like depression. Hypertension and tachycardia are also common.
What is the typical age range for onset of AIP symptoms?
20-40 years old.
Is AIP more common in males or females?
AIP is more common in females, with a ratio of 5:1.
What is Trypanosoma Cruzi?
Trypanosoma Cruzi is a protozoan that causes Chagas disease.
How can AIP be diagnosed?
Classically, the urine turns deep red on standing. Other diagnostic markers include elevated urinary porphobilinogen (elevated between attacks and to a greater extent during acute attacks), assay of red cells for porphobilinogen deaminase, and raised serum levels of delta aminolevulinic acid and porphobilinogen.
Where does Trypanosoma Cruzi proliferate within the body?
It undergoes intracellular proliferation in various sites, including the CNS, intestinal myenteric plexus, spleen, lymph nodes, and cardiac muscle.
How is Trypanosoma Cruzi transmitted?
It is carried by bugs that infect the skin while feeding. The protozoan can penetrate through open wounds and mucous membranes.
Which areas of the body are major sites of infection for Trypanosoma Cruzi?
The CNS, intestinal myenteric plexus, spleen, lymph nodes, and cardiac muscle are major infective sites for Trypanosoma Cruzi.
What medication is used to treat acute Trypanosoma Cruzi infection?
Nifurtimox is used to treat acute infection caused by Trypanosoma Cruzi.
Is Chagas disease reversible or irreversible?
Chronic Chagas disease is irreversible.
What are sarcomas?
Sarcomas are malignant tumors that originate from mesenchymal tissues.
What are the two types of sarcomas based on origin?
Sarcomas can be either bone or soft tissue in origin.
Name three types of bone sarcomas.
Osteosarcoma, Ewing’s sarcoma (can also occur in non-bony sites), and chondrosarcoma (originates from chondrocytes).
Name four types of soft tissue sarcomas.
Liposarcoma (adipocytes), rhabdomyosarcoma (striated muscle), leiomyosarcoma (smooth muscle), and synovial sarcoma (close to joints, but not originating from the synovium).
What is malignant fibrous histiocytoma?
Malignant fibrous histiocytoma is a sarcoma that can arise in both soft tissue and bone.
What features raise suspicion for a sarcoma?
Features that raise suspicion for a sarcoma include a large (>5cm) soft tissue mass, deep tissue or intra-muscular location, rapid growth, and a painful lump.
What imaging modalities are used to assess suspicious masses?
Imaging of suspicious masses should include a combination of MRI, CT, and ultrasound (USS).
Should blind biopsy be performed before imaging?
No, blind biopsy should not be performed prior to imaging. If biopsy is required, it should be done in a way that allows the biopsy tract to be included in any subsequent resection.
Is Ewing’s sarcoma more common in males or females?
Ewing’s sarcoma is more common in males.
At what age does Ewing’s sarcoma typically onset?
Ewing’s sarcoma typically onsets between the ages of 10 and 20 years.
Which location is the most common site for Ewing’s sarcoma?
The femoral diaphysis is the most common site for Ewing’s sarcoma.
How does Ewing’s sarcoma appear histologically?
Histologically, Ewing’s sarcoma is a small round tumor.
Is blood-borne metastasis common in Ewing’s sarcoma?
Yes, blood-borne metastasis is common in Ewing’s sarcoma, and chemotherapy is often combined with surgery for treatment.
What type of cells are involved in osteosarcoma?
Osteosarcoma involves mesenchymal cells with osteoblastic differentiation.
At what age does osteosarcoma most commonly occur?
Osteosarcoma most commonly occurs in the age range of 15-30, and it is more common in males.
Is limb-preserving surgery possible in osteosarcoma cases?
Limb-preserving surgery may be possible in osteosarcoma cases, and many patients will also receive chemotherapy as part of their treatment.
What are the characteristics of liposarcoma?
Liposarcoma is a malignancy of adipocytes. It is a relatively rare soft tissue sarcoma, with an incidence of approximately 2.5 per 1,000,000. It is typically located in deep areas such as the retroperitoneum. Liposarcomas can affect an older age group, usually over 40 years of age. They may be well differentiated and slow-growing but can undergo dedifferentiation and disease progression. Surgeons should be cautious of pseudocapsules, as tumor invasion can occur at the edge, leading to local recurrence. Liposarcomas are usually resistant to radiotherapy but may be used in a palliative setting.
What are the main subtypes of malignant fibrous histiocytoma?
The main subtypes of malignant fibrous histiocytoma are storiform-pleomorphic (70% of cases), myxoid (less aggressive), giant cell, and inflammatory. Treatment usually involves surgical resection and adjuvant radiotherapy to reduce the likelihood of local recurrence.
