Histopathology 3) Cytopathology Flashcards
What are examples of gynaecological cytopathology?
NHS CSP smears
Diagnostic smears and endometrial sampling
What are examples of non-gynaecological cytopathology?
Exfoliative - serious effusion, joint, respiratory, GI, CSF
Aspiration - lymph node, salivary gland, skin and soft tissue masses, cyst, breast, thyroid
Where are serous membranes found?
Pericardium
Pleura
Abdominal cavity (peritoneum)
Tunica vaginalis of testes
How is a serous effusion formed?
Serous membranes well supplied with capillaries with high fluid turnover
Effusion is an imbalance between formation and resorption
Hydrostatic pressure in capillaries, oncotic pressure, vascular permeability
Resorption via lymphatics, capillaries and venules
Why is a transudate effusion formed?
Increased mechanical pressure - increased hydrostatic pressure or decreased oncotic pressure
What is a transudate effusion?
Clear, pale yellow, low protein, doesn’t clot
Single bland degenerate mesothelial cells and a few macrophages and lymphocytes
Cardiac, cirrhosis, nephrotic, hypoproteinaemia
What is an exudate effusion?
Unfiltered plasma Changes in vascular permeability Cloudy, yellow or bloody, high protein, clots Many cells with proteinaceous background Inflammation May be malignant
What do pale yellow and watery cells indicate?
Transudates from CCF, cirrhosis, decreased protein
What do turbid and yellow to white cells indicate?
Infection
Malignancy
Pancreatitis
What do milky white / greenish cells indicate?
Chylous effusion from thoracic duct, obstruction
What do milky green with a silky sheen cells indicate?
Pseudochylous effusion caused by cholesterol from TB, rheumatoid disease or an old effusion
What do brown cells indicate?
Haemorrhage or melanin
What do green cells indicate?
Bile from biliary tract disease or ruptured bowel
What do gelatinous cells indicate?
Hyaluronic acid from mesothelioma or mucin in pseudomyxoma
What do mesothelial cells in effusions look like?
Mesodermal epithelium Microvilli Single and grouped Clusters, balls, papillae, cell-in-cell Vary in size Lacy edges Windows Molding Variable nuclear number, size, N:C ratio Perinuclear cytoplasmic density Vacuoles - glycogen, fat, degeneration
What do macrophages in effusions look like?
Usually present Can be difficult to separate from mesothelial cells Usually single or in loose aggregates Foamy pale cytoplasm Eccentric bean shaped nucleus Lack holding, windows
What do lymphocytes in effusions look like?
Usually a few present
More frequent in longstanding effusions
May be a range of maturation
What are lymphocyte effusions associated with?
Obstructed circulation through lymph nodes and associated with tuberculosis and lymphoma
What are eosinophils in effusions indicate?
Mostly pleura
Generally non-specific
Mostly benign
What do neutrophils in effusions indicate?
Often find a few
If non-infectious, may be well-preserved
If infectious, often degenerate
If masses, usually benign
What other cells can be found in effusions?
Plasma cells Ciliated cells Micro-organisms Megakaryocytes Stranges - LE cells and ferruginous bodies
What are the features of malignant cells?
Architecture - groups - dispersed single cells Nuclei of malignant cells - increased N:C ratio - irregular membrane - inclusions - coarse irregular chromatin Cytoplasm - various vacuoles - mucin - melanin - keratinisation
What do malignant breast cells look like?
Several patterns (often clustered) Proliferation spheres Diffuse cell pattern Small single cells of lobular carcinoma - intracytoplasmic lumina - microvilli and mucin - indian files
What do malignant lung cells look like?
Range of patterns of differentiation
Dense cytoplasm
Papillary groups
May be highly vacuolated
What do malignant stomach cells look like?
Dispersed single cells but may form papillae or acini
Signet ring of columnar cells
Signet ring cells have many tiny vacuoles
Can be bland with cells like macrophages
What do malignant colorectal cells look like?
Papillary and acing aggregates
Tall columnar cells
Nuclear palisading with nuclear membrane irregularities
Why is fine needle aspiration good for patients?
Minimal past and post-procedural discomfort
Anaesthesia requirement is minimal, outpatient procedure
Rapid result
Why is fine needle aspiration good for clinical management?
Easily repeated
Minimal distribution of tissue planes
Confirms malignancy leaving lesion intact
Therapeutic for cysts and abscesses
Quick feedback allows planning of other investigations
Why is fine needle aspiration good for pathologists?
Simple and cheap equipment
Excellent cell preservation due to rapid fixation
Fresh tissue available
What are the features of fixed fine needle aspiration?
Nuclear detail Transparent Keratinisation Squamous differentiation Hyperchromasia Necrosis Similar to histology Stain papnicoloau or H&E
What are the features of air-dried fine needle aspiration?
Cytoplasmic features Background substance Mucin, granules Glandular and lymphoid Metachromasia Microbial agents Bit like marrow Stain MGG
What are alternative causes of reactive lymphadenopathy?
Non-specific lymphoid hyperplasia HIV-associated Mononucleosis RA, SLE, syphilis Dermatopathic changes
What can cause granulomatous lymphadenitis?
TB Cat scratch, leprosy, paracoccidioidomycosis, histoplasmosis, LGV Foreign body Lymphoma Carcinoma Sarcoid
What is required for a lung cancer diagnosis?
Adequate aspirate
Morphologic diagnosis
Immunophenotypic confirmation
Material to permit molecular genetic evaluation
What is the accuracy of fine needle aspiration diagnosis?
Specificity 94-100%
Sensitivity 81-100%
What are false negatives of fine-needle aspiration associated with?
Non-representative sampling
