Meningiomas

Question 1

Meningothelial

Answer 1

Skull base
WHO 1
AKT1 (pE17k) combined with TRAF7/PIK3CA/SMO

Question 2

Fibrous

Answer 2

Convexity
22q deletion/NF2

Question 3

Transitional

Answer 3

Convexity
22q deletion/NF2
EMA often reduced, S100 positive
DD: SFT

Question 4

Psammomatous

Answer 4

Thoracic spine, middle aged women
22q deletion/NF2

Question 5

Angiomatous

Answer 5

WHO 1
Gain of Chr5
DD: haemangioblastoma

Question 6

Microcystic

Answer 6

WHO 1
Gain of Chr 5
Inhibin negative

Question 7

Metaplastic

Answer 7

WHO 1
Areas of osseus, cartilaginous, lipomatous, myxoid and xanthomatous tissue
Gain of Chr5

Question 8

Secretory

Answer 8

WHO 1
Oedema
Increased CEA levels
Combined KLF4/TRAF7 mutation
IHC: PAS/CEA positive inclusions

Question 9

Lymphoplasmacyte-rich

Answer 9

WHO 1
Genetics: nil

Question 10

Chordoid

Answer 10

Large, supratentorial
WHO 2
Age - 45
Genetics: 2p deletions overrepresented
DD: chordoma (CK, brachyury - both negative in meningioma)
Associations: rarely anaemia or Castleman’s disease

Question 11

Clear cell

Answer 11

Younger people - mean 24
Cerebellopontine angle, cauda equina
Genetics: loss of SMARCE1
IHC: PAS-positive, loss of SMARCE1

Question 12

Rhabdoid

Answer 12

WHO 3
Significance of rhabdoid morphology in isolation debated
IHC: BAP1 loss (poor prognostic indicator)
Genetics: BAP1
Associations: BAP1 syndrome (uveal and cutaneous melanoma, mesothelioma, RCC)

Question 13

Papillary

Answer 13

WHO3
Children and adults
Oedema and hyperostosis/destruction
Genetics: PRBM1, BAP1 (overlap with rhabdoid)

Question 14

Anaplastic

Answer 14

WHO 3
20+ mitoses per 10 HPF
Can resemble carcinoma, sarcoma or melanoma
IHC: H3k27me3 loss in 10-20%, poorer prognosis
Genetics: TERT mutation, homozygous CDKNA/B deletion

Question 15

Atypical

Answer 15

WHO 2
4+/10 HPF, brain in invasion and/or 3 of: increased cellularity, small cells, sheeting, nucleoli, necrosis