Head and neck tumours Flashcards
Gross and microscopic feature of pleomorphic adenoma
Benign epithelial tumor that shows epithelial, myoepithelial, and mesenchymal differentiation
Gross - irregular mass, fibrous capsule in parotid but poorly developed in minor glands, homogenous cut surface, haemorrhage or infaction secondary to previous bx
Micro -innumerable patterns
solid, tubular, trabecular or cystic
ducts - lined by cuboidal or columnar epithelium
Epithelial - spindle, clear, plasmacytoid, basaloid, squamous metaplasia, verocay-like structures, Less commonly sebaceous, mucous, oncocytic cells.
Mesenchymal - chondromyxoid, hyaline, calcified, bone foci, and rarely fatty
Rarely crystals
IPx sensitive but not specific, CK, p63, GFAP, s100, PLAG1, SMA, variably positive
Immunohistochemistry for Pleomorphic adenoma
CK, p63, GFAP, S100
70% show PLAG1 or HMGA2 rearrangements
What is the significance of hypocellular hyalinised tissue in a pleomorphic adenoma?
Hypocellular hyalinised stroma in a PA is an atypical feature, associated with increased risk of malignant transformation to carcinoma ex PA. Additional blocks recommended when this feature is present.
IPx for adenosquamous carcinoma
AdenoCa positive for CK7, CEA
SCC positive for p40, p63, CK5/6
Special stain and Ipx for Acinic cell carcinoma
PAS(+) diastase resistant zymogen granules
Negative or focally positive granules with mucicarmine
NR4A3 -highly specifice nuclear marker
DOG1: delicate membrane stain- accentuated luminal border
Ancillary test for secretory carcinoma of salivary gland
Special Stains: Colloid like secretions are PASD negative
IPX: Positive for CK7, mammaglobin, s100, sox10, GATA3, STAT5a, GCDFP15, MUC1, MUC4 (variable) positive
Negative for p63, p40, ck5/6, DOG1, SMA, calponin, CK14
FISH breakapart probe for ETV6 in many cases.
Ancillary test for Cystadenocarcinoma of salivary gland
PASD or mucicarmine for mucin - uncommon to have strong reaction
Positive for panCK, CK7, CEA-M, EMA, s100(variable)
Negative: AR, P63, mammaglobin, GCDFP-15, CK5/6, SMA
Ancillary test for mucoepidermoid
Mucicarmine positive mucocytes
CK5/6 highlight intermediate cells and epidermoid cells, but intermediate cells may not stain sometimes.
EMA accentuates mucocytes
CRTC1-MAML2 fusion
Ancillary test for sinonasal adenocarcinoma, intestinal type
PASD and Mucicarmine positive in intracytoplasmic and intraluminal.
CK20
CDX-2 - nuclear positive
Villin negative - positive if metastatic colorectal ca and normally expressed in the brush border of epithelial cells of the GIT, renal PCT and hepatobiliary tract.
ancillary test for nodular fasciitis
Molecular: USP6 gene rearrangement in most cases
USP6-MYH9 fusion is most common
ancillary test for adenoid cystic carcinoma of salivary gland
PAS and alcian blue - high lights basement membrane material of pseudolumina
Ancillary test for salivary duct carcinoma
Mucicarmine and alcine blue - non-reactive
Positive for Androgen receptor, CK7,
Negative CK5/6 and p63
Her2 positive in many
Most SDC are carcinoma ex pleomorphic adenoma, when pleomorphic are no long PLAG1 or HMGA2 positive.
Ancillary test for clear cell carcinoma of salivary gland
PAS- diastase sensitive
Mucicarmine + in 50% cases
Positive Ck, p63, p40
Neg S100, SMA, Myosin, GFAP, CK20
FISH for EWSR1 translocation
Molecular test and special test for Mammary Analogue Secretory Carcinoma
also known as zymogen poor acinic cell carcinoma
Mucin vacuoles stain with mucicarmine, alcian blue, and PAS without diastase
ETV6 translocations are characteristic, usually detected by FISH break-apart probes
t(12,15)(p13;q25) ETV6-NTRK3 translocation is typical
Specific to secretory carcinoma (in salivary gland)
ETV6 can also rarely have other translocation partners
