MISC Flashcards
CK 7/20 man diagram
CK7+20+ peridiaphgragm & bladder, pancreaticobiliary, stomach, bladder, ovary(mucinous)
CK7+20- above diaphragm and female gynae, Breast, lung (ca and meso), endometrium, ovary (non-mucinous), thyroid, salivary gland, kidney (papillary RCC)
CK7-CK20+ below diaphragm, colorectal, merkel
CK7-CK20- (simple visceral except colon) liver(HCC), kidney (clear cell RCC), prostate, adrenal cortex.
IHC for glomus tumour
Ancillary Tests
SMA, caldesmon (+)
Desmin, S100, keratin (-)
IHC for germ cell tumours
Microscopic features and IHC for Angiomatoid fibrous histiocytoma
Microscopic
Fibrous pseudocapsule with lymphoplasmacytic cuff (80% of cases)
Sheets, nodules, and aggregates of ovoid to spindled cells
Most cells are cytologically bland with vesicular nuclei; mitoses infrequent
Scattered cells with nuclear hyperchromasia and pleomorphism are common
Variably sized, blood-filled pseudovascular spaces in majority of cases
Ancillary Tests
Desmin (+) in 50-60% of cases
ALK (+) by IHC common
Variable, nonspecific expression of EMA, CD68, CD99, SMA
Molecular: t(2:22) with EWSR1-CREB1 fusion most common
IHC for benign peripheral nerve sheath tumours
Schwannoma
Diffuse strong positivity for S100 protein and SOX10 is characteristic
Neurofibroma
S100/S0X10 (+) in ~ 50% of total cells (Schwann cells)
CD34(+) admixed spindled fibroblasts
EMA(+) admixed perineurial cells
Neurofilament protein highlights intratumoral axons
Intact nuclear H3K27me3 expression
Ki-67, p53, and p16 markers are of limited utility
perineurioma
Variably positive with perineurial markers
EMA: Strong and diffuse in all cases
Claudin-1: Distinctly particulate pattern along cell membrane in nearly all cases
GLUT1: Usually membranous to stippled
CD34: Up to 65% of tumors may be positive
May have SMA (~ 20%) and S100 (~ 5%)
Strong membranous staining with collagen IV
Haemangioblastoma
WHO grade 1
Highly vascular, reactive vascular cells
neoplastic stromal cells, clear to vacuolated cytoplasm, numerous lipid containing vacuoles
solid epithelioid aggregates associated with extramedullary haematopoiesos
Mitosis are rare
can mimic metastatic RCC
Imaging: often cerebellar, contrast-enhancing nodules frequently associated cystic structures.
IHC - inhibin positive, D2-40, and brachyury (cytoplasmic)
Molecular - VHL alterations
Frequent manifestation of VHL
Brenner
vs
Borderline Brenner
vs
Malignant Brenner
tumours with nests of bland transitional/urothelial epithelium set within fibromatous stroma
Borderline - resemble LG PUN of the urothelial tract, increased mitotic activity
Malignant - stromal invasion, infiltrative nests with desmoplastic stromal response
Benign - GATA3, CK7, p63, S100P, AR, uroplakin, and thrombomodulin, but they do not express (or only focally express) CK20. PAX8, ER, and PR are typically negative
Compare Papillary Urothelial Carcinoma - GATA3, CK20, p63, CK5/6 and high molecular weight CKs.
Borderline - positive for p63 and GATA3 and negative for ER, PR, and WT1. p53 shows a wildtype immunoreactive pattern, and p16 can show loss of staining.
Malignant: These tumours are usually negative for WT1, negative or weakly positive for ER and PR, and focally positive for p16, showing a wildtype pattern for TP53. The data for GATA3 and p63 are very limited, because only one case was published and negative for GATA3, in contrast to benign and borderline Brenner tumours, which were positive. p63 was positive in all Brenner tumours.
Medulloblastoma
Medulloblastoma is an embryonal neuroepithelial tumour arising in the posterior fossa, histologically characterized by small, poorly differentiated cells with a high N:C ratio and high levels of mitotic activity and apoptosis.
lassic medulloblastomas are typically located in the cerebellar midline, involving the fourth ventricle cavity, with or without close contact with the brainstem.
Classic medulloblastoma; desmoplastic/nodular medulloblastoma; medulloblastoma with extensive nodularity; large cell / anaplastic medulloblastoma
Medulloblastoma - WNT activated, SHH actived and TP53 wildtype or TP53 mutant, nonWNT and Non-SHH - worse prognosis
Synovial sarcoma
monophasic- dense cellular sheets, vague fascicles of uniform spindle cells,
biphasic - contain epithelial structures
CK+, EMA+, TLE-1 strong diffuse positive, CD56 and CD99 +,
CD34 neg, SMA, desmin, synaptophysin, TTF-1 neg
Molecular -characteristic t(x;18)(p11;q11) - Fusion of SSX gene at Xp11 (ssx1 (most common) ssx2 or ssx4), fusion to ss18 gene at 18q11
Other rarer possible gene re-arrangement
MiT family translocation RCC
Histo features and Molecular
papillary neoplasm with epithelioid clear cells, abundant psammoma bodies, can resemble Clear cell RCC, papillary RCC, multiloclar cystic renal neoplasm of LMP, oncocytoma, epithelioid angiomyolipoma
Melanin pigment (TFE3 fusion)
t(6;11) translocation, biphasic- nests of larger epithelioid cells and small cells clustered around basement membrane material, entrap renal tubules at the peripheries
Immuno - underexpress CKs and EMA, but PAX8 positive and other renal markers
t(6;11) RCC express melan A and HMB45, cathepsin k, Xp11 melano markers, but only 60% cathepsin k
Molecular - Xp11 -TFE3 immuno, TFE3 break apart FISH
t(6;11) -TFEB immuno, and TFEB break apart FISH
Solitary fibrous tumour
patternless pattern
uniform, spindled to ovoid fibroblastic cells
staghorn vascular pattern
fibrous stroma with abundant collagen
myxoid stroma
less than 3 mitoses per 10HPF
Ancillary: strong diffuse CD34+ and stat6+
CK, s100, desmin, cd117, CD31 are negative
Molecular: NAB2-stat6 fusion
differential for metanephric adenoma and how to distinguish them
- Type 1 papillary RCC (fibrous pseudocapsule, most MA has no pseudocapsule), high grade nuclei, more cytoplasm, diffusely positive for AMACR, ck7, EMA and MUC1, negative for WT1 and CD57
MA is positive for WT1, and negative for CK7
MA positive for BRAF V600E
- Epithelial predominant Wilms Tumour
pseudocapsule, nuclei hyperchromatic, brisk mitoses, nuclear overlap, stroma and blastemal component, negative for CD57 (or only focal), BRAF V600E negative
Kimura disease
Chronic inflammatory disease that affects subcutaneous tissue and regional lymph nodes
Benign clinical cause and recurrence is common
unknown/possible infectious etiology
young Asian
nontender head and neck subcut masses, regional lymphadenopathy
peripheral eosinophilia and elevated serum IgE
Micro:
Skin: deep subcut, reactive follicles, prominent germinal centers, eosinophilia and vascular hyperplasia
Node: hyperplastic follicles, eosinophilia, eosinophilic microabscess, stromal and perivascular sclerosis
ependymoma
WHO Grade II
well circumscribed heterogenous contrast enhancement
Gliofribrillar background, monomorphic cells, round nuclei, true rosette, perivascular rosettes,
IPX: GFAP+, EMA+(perinuclear dot like),
Ancillary: chromsome 22/22q loss or 1q gain, NF2 association
tubular / cribriform carcinoma breast
Tubular: haphazard, infiltrative, tubules are angular with open lumina and tapering ends, single layer of epithelial cells, no myoepithelial layer, bland cellular features
Cribriform: haphazard infiltrative, irregular cribriform nests with fenestrated apearance, resembles cribriform DCIS. Bland cellular features
IPX: ER PR+, HEr2 neg generally, low Ki67, absent myoepithelial markers.
DDx: sclerosing adenosis, radial sclerosing lesion, IDC, DCIS, microglandular adenosis (ER, PR neg but s100+), adenoid cystic - has epithelial and myoepithelial cells.,
