302 Pathophysiology and cytopathology of ascites Flashcards
What are the 6 causes of ascites?
Fluid
Flatus
Faeces
Fat
Faetus
Neoplasia, Inflammation, Infection, or rarities like sarcoidosis
What are the clinical presentations of ascites?
Flank dullness on examination, shifting dullness, a fluid wave, evidence of pleural effusions
What causes caput medusae?
Portal hypertension
Dilated superficial (superior and inferior) epigastric veins radiating from a central large venous varix
What is paracentesis?
the perforation of a cavity of the body or of a cyst or similar outgrowth
What is the equation for filtration/reabsorption rate?
Qf = P eff (Difference between hydrostatic/blood pressure minus oncotic pressure) x K f (permeability x exchange area
Affected by:
Change in hydrostatic pressure
Change in oncotic pressure
Change in permeability
Change in exchange area
What are serous membranes?
The outer lining of organs and body cavities of the abdomen and chest, including the stomach
Eg. Pericardium, pleura, peritoneum, tunica vaginalis of testis
What are the limitations for clinical detection of effusions in different serous membranes?
Ascites 500 ml
pleura 300 ml
pericardium 50ml
Effusions are always pathological
What is a transudate effusion?
Plasma filtrate with low protein content
Caused by change in hydrostatic or oncotic pressure
What is an exudate effusion?
Unfiltered plasma with high protein content
Caused by change in vascular permeability or exchange area
What are the causes of portal hypertension?
liver cirrhosis (80%)
alcoholic hepatitis
chronic cardiac failure
constrictive pericarditis
What are the causes of hypoalbuminaemia?
nephrotic syndrome
protein losing enteropathy
malnutrition
What is the role of albumin?
Helps keep fluid from leaking out of your blood vessels into other tissues
What are the different causes of ascites?
Portal hypertension liver cirrhosis (80%)
= hydrostatic
Hypoalbuminaemia
= oncotic
Peritoneal disease
= permeability
= exchange area
Others:
chylous ascites (lymphatic blockage e.g. in malignancy)
haemoperitoneum
pancreatic disease
sarcoidosis
What is peritoneal disease?
A pattern of metastatic disease where cancer has spread from where it initially started into the lining of the abdominal cavity
What is SAAG?
SAAG = serum albumin – ascites albumin
A high gradient (SAAG >1.1 g/dL) indicates portal hypertension and suggests a nonperitoneal cause of ascites
What does Pale yellow and watery ascites fluid indicate?
Transudate from CCF cirrhosis protein etc
What does turgid and yellow to white ascites fluid indicate?
Infection, malignancy, pancreatitis
What does milky/white/ green ascites fluid indicate?
Chylous effusion caused by cholesterol from TB, rheumatoid disease or an old effusion
What is a chylous effusion?
An accumulation of chyle in the pleural space due to disruption or obstruction of the thoracic duct
What does brown ascites fluid indicate?
Haemorrhage (trauma, pancreatitis, malignancy) or melanin
What does green ascites fluid indicate?
Bile from biliary tract disease or ruptured bowel
What does gelatinous ascites fluid indicate?
Hyaluronic acid from mesothelioma or mucin in pseudomyxoma peritonei
Which cells are present in effusions?
Mesothelial
Macrophages
Lymphocytes
Eosinophils
Neutrophils
Plasma Cells
Strangers
How do mesothelial cells present in ascites fluid?
Variable nuclear number, size, N:C ratio
Perinuclear cytoplasmic density
Peripheral lacy border
Mesodermal epithelium
Have microvilli
Single and grouped
Clusters, balls, papillae, cell-in-cell, single cell files
If malignant = mesothelioma
How do macrophages present in ascites fluid?
Usually present
Can be difficult to separate from mesothelial cells (esp. degenerate)
Usually single or in loose aggregates
Foamy pale cytoplasm
Eccentric bean shaped nucleus
Lack moulding, windows
How do lymphocytes present in ascites fluid?
Usually a few present
More frequent in longstanding effusions
May be a range of maturation
Lymphocytic effusions are associated with obstructed circulation through lymph nodes and associated with tuberculosis or lymphoma
How do neutrophiles present in ascites fluid?
If non-infectious may be well preserved
If infectious then often degenerate
If masses then usually benign
Present in:
Infection
Infarction
Gastrointestinal disease
Foreign body
Beware early tuberculous
Malignancy
What are degenerate cells?
A pathological condition that causes cells to change in structure and function
What is a charcot leyden crystal?
Charcot Leyden crystals are hexagonal bipyramidal structures localised in the primary granules of the cytoplasm of eosinophils and basophils
Their presence, along with eosinophilic infiltrate, is an indirect evidence of parasitic infestation
How do eosinophils present in ascites fluid?
Eosinophilia < 10 %
Pleura mostly
Generally not specific
Mostly benign but rarely malignant
Air is a stimulus so more common with repeated aspiration
What are Ferruginous Bodies?
A characteristic finding of asbestos exposure is the ferruginous body, a microscopic rod-shaped body with clubbed end
What is the architecture of malignant cells?
Groups – Clumps, Balls, Papillae, Glands
vs
Normally dispersed single cells
with pleomorphism
How does malignancy appear in the lung?
Range of patterns of differentiation (large cell/adeno/squame)
Dense cytoplasm
Papillary groups
May be highly vacuolated
Vacuolated meaning
Formed into or containing one or more vacuoles or small membrane-bound cavities within a cell
How does malignancy appear in the stomach?
Usually dispersed single cells but may form papillae or acini
Signet ring or columnar cells
Signet ring cells have many tiny vacuoles
Can be rather bland with cells like macrophages
What are the features of mesothelioma?
Diffuse nodular pleural thickening (versus discrete)
Often unilateral (versus bilateral)
Thickening of fissures (versus intraparenchymal nodules)
What is an FNA test?
A fine needle aspiration (FNA)
What are the benefits of performing a fine needle aspiration?
Easily repeated allowing sampling of several areas with minimal trauma
Minimal disturbance of tissue planes
Confirms malignancy leaving lesion intact
May be therapeutic for cysts and abscesses
Quick feedback enables planning of other investigations
Monitor therapy by repeated sampling
What is formalin?
A solution of formaldehyde and water
It destroys all cytology
What is the difference between fixed and air dried cytology?
Dried with air or alcohol
What are cytospins?
Tissue pellet for further special stains or immunochemistry or molecular biologic tests
What is Reactive lymphadenopathy?
When lymph glands respond to infection by becoming swollen
Eg. Non-specific lymphoid hyperplasia
HIV-associated
Mononucleosis
RA, SLE, Syphilis
Dermatopathic changes
What is Granulomatous lymphadenitis?
A chronic inflammatory condition that can be associated with lymphoproliferative, infectious and autoimmune diseases
Caused by eg.
TB
Cat scratch, leprosy, paracoccidioidomycosis, histoplasmosis, leishmaniasis, LGV, brucellosis
Foreign body (talc, silica)
Lymphoma
Carcinoma
Sarcoid
What is a granuloma?
A collection of activated epithelial histiocytes
