Histopathology 3: Cytopathology Flashcards
what is cytopathology split into?
Gynaecological Cytopathology
NHS CSP smears
Diagnostic (symptomatic) smears and endometrial sampling
Non-Gynaecological Cytopathology
Exfoliative (serous effusion, joint, respiratory, GI, CSF)
Aspiration (lymph node, salivary gland, skin and soft tissue masses, cysts, breast, thyroid…)
list 5 serous membranes
Pericardium, Pleura, Abdominal Cavity, Tunica Vaginalis of testis
what is a serous membrane?
Connective tissue lined by mesothelial cells
what are the features of the a transudate?
Plasma ultrafiltrate
‘Mechanical’ –Hydrostatic Oncotic
Clear, pale yellow, low protein (<3g/dL), doesn’t clot
Single bland degenerate mesothelial cells and a few macrophages and lymphocytes
usually benign
causes of transudate?
Cardiac, Cirrhosis, Nephrotic, Hypoproteinemia
what are the features of the a exudate?
Unfiltered plasma
Changes in vascular permeability
Cloudy, yellow or bloody, high protein (>3g/dL), clots
Many cells with proteinaceous background
Inflammation (infection, infarction, autoimmune)
May be malignant
if it is pale yellow and watery, what does it point towards?
Transudate from CCF cirrhosis protein
if it is turbid and yellow/white?
Infection, malignancy, pancreatitis
if it is milky white/greenish?
Chylous effusion from thoracic duct obstruction (trauma, lymphoma)
if it is milky with a silky sheen ?
Pseudochylous effusion caused by cholesterol from TB, rheumatoid disease or an old effusion
if it is brown?
Haemorrhage (trauma pancreatitis malignancy) or melanin
if it is green?
Bile from biliary tract disease or ruptured bowel
if it is gelatinous
Hyaluronic acid from mesothelioma or mucin in pseudomyxoma
features of mesothelial cells
mesodermal epithelium Microvilli Single and grouped Clusters, balls, papillae, cell-in-cell, indian files Vary in size Lacy edges Windows Molding
features of macrophages?
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 molding, windows
features of lymphocytes?
Usually a few present
More frequent in longstanding effusions
May be a range of maturation
features of neutorphils
Often find a few
If non-infectious may be well preserved
If infectious then often degenerate
If masses then usually benign
what is an LE cell?
A neutrophil or macrophage with an engulfed/phagocytised nucleus seen in SLE
what are the features of malignancy?
Enlarged Increased N:C ratio Irregular membranes Inclusions Coarse Irregular Chromatin
what features are seen in breast Ca on cytology?
Proliferation spheres Diffuse cell pattern Intracytoplasmic lumina, may dilate to look like signet ring Microvilli and mucin Indian files
what features are seen in lung Ca on cytology?
Dense cytoplasm
Papillary groups
May be highly vacuolated
what features are seen in stomach Ca on cytology?
Usually dispersed single cells but may form papillae or acini
Signet ring or columnar cells
Signet ring cells have many tiny vacuoles
what features are seen in CRC on cytology?
Papillary and acinar aggregates
Tall columnar cells
Nuclear palisading with nuclear membrane irregularities
what are the features of mesothelioma compared to carcinoma?
Diffuse nodular pleural thickening (versus discrete) Often unilateral (versus bilateral) Thickening of fissures (versus intraparenchymal nodules)
what are specific markers of mesothelioma?
Calretinin (cplasm+nuclei)
CK5/6 (cplasm)
what are the pros of FNA?
Minimal pain and post procedural discomfort
Anaesthesia requirement minimal
Outpatient procedure
Saves time and hospital admission
Rapid result
Equipment simple and cheap
Excellent cell preservation due to rapid fixation
Fresh tissue available eg for microbiology or genetic analysis
why is FNA good for management ?
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
how do you fix cytology?
air dry or alcohol fix NEVER IN FORMALIN.
compare air dried vs alcohol fixation
Fixed: nuclear detail transparent keratinisation squamous differentiation hyperchromasia necrosis bit like histology
Air dried: cytoplasmic features background substance mucin, granules glandular and lymphoid metachromasia microbial agents bit like marrow
where can cells originate from for a FNA of LN?
Cells from germinal centres
Cells from interfollicular areas and sinuses
what would cause granulomatous lymphadenitis ?
TB Cat scratch, leprosy, paracoccidioidomycosis, histoplasmosis, leishmaniasis, LGV, brucellosis Foreign body (talc, silica) Lymphoma Carcinoma Sarcoid
define granuloma
a collection of activated epithelioid histiocytes
