MISC Flashcards

1
Q

CK 7/20 man diagram

A

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.

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2
Q

IHC for glomus tumour

A

Ancillary Tests

SMA, caldesmon (+)

Desmin, S100, keratin (-)

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3
Q

IHC for germ cell tumours

A
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4
Q

Microscopic features and IHC for Angiomatoid fibrous histiocytoma

A

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

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5
Q

IHC for benign peripheral nerve sheath tumours

A

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

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6
Q

Haemangioblastoma

A

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

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7
Q

Brenner

vs

Borderline Brenner

vs

Malignant Brenner

A

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.

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8
Q

Medulloblastoma

A

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

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9
Q

Synovial sarcoma

A

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

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10
Q

MiT family translocation RCC

Histo features and Molecular

A

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

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11
Q

Solitary fibrous tumour

A

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

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12
Q

differential for metanephric adenoma and how to distinguish them

A
  1. 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

  1. Epithelial predominant Wilms Tumour

pseudocapsule, nuclei hyperchromatic, brisk mitoses, nuclear overlap, stroma and blastemal component, negative for CD57 (or only focal), BRAF V600E negative

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13
Q

Kimura disease

A

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

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14
Q

ependymoma

A

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

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15
Q

tubular / cribriform carcinoma breast

A

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.,

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16
Q

chordoma

A

Primary malignant tumour of bone recapitulates notochord and arises within bones of axial skeleton.

classified into conventional, chondroid chordoma, and dedifferentiated chordoma

Conventional: lobulated, infiltrates marrow, encase bone forms well demarcated soft tissue mass

large epithelioid cells in cohesive nests and cords

Abundant pink cytoplasm, small nucleoli, clear vacuoles- physaliphorous cells

Chondroid: mimics chondrosarcoma abuts conventional type

Dedifferentiated: high grade sarcomatous with conventional chordoma

IPX: EMA and CK8 and 19, brachyury, s100, chondrosarc is negative for CKs, dedifferentiated chordoma losses staining, and also loss of INI1 staining.

17
Q

central neurocytoma

A

consider this if discrete intraventricular oligodendroglial like tumour near foramen on Monro.

Cells in sheets or large lobules

Remarkable cytological uniformity

Artifactual perinuclear halos lend oligodendroglioma-like appearance, sometimes striking

Ependymoma-like perivascular pseudorosette-like, nucleus-free zones &/or larger patches of neuropil

Microcalcifications, frequent

Delicate vessels, with little surrounding stroma

Differentiation to ganglion cells, uncommon

Lipidization, rare

Atypical neurocytoma defined by Ki-67 labeling indices > 2 or 3%

Increased mitoses (usually ≥ 3 per 10 HPF)

Atypia, often minor

Microvascular proliferation, some cases

Necrosis, some cases

Ki-67 labeling index not uniform prognostic factor in all studies