Lung

Question 1

cystic lung lesions

Answer 1

bronchogenic cyst

ciliated foregut cyst

enterogenous cyst

CCAM

sequestration

bronchial atresia

congenital lobar overinflation

mesothelial cyst

lymphatic malformation

pleuropulmonary blastoma

Question 2

CPAM vs sequestration

Answer 2

CPAM: communicates with tracheobronchial tree, normal pulmonary artery supply, 3 types (depend on number and size of cyst)

Seq: prominent systemic artery, extralobar (own pleural covering) or intralobar

Question 3

spindle cell lesions

Answer 3

non-neo: mycobacterial pseudotumour, organizing pneumonia

epithelial: spindle cell carcinoid, spindle cell carcinoa, thymoma
mesenchymal: SFT, IMT, synovial sarcoma, lymphangioleiomyomatosis, PEComa, leiomyoma/LMS, Kaposi sarcoma

mesothelioma

melanoma

Question 4

biphasic lesions

Answer 4

carcinoid

adenosquamous ca

carcinosarcoma

synovial sarcoma

fetal adenocarcinoma (looks like endometrioid ca with sq morules)

pulmonary blastoma (adults, fetal adenoca-like with malignant primitive stroma)

pleuropulmonary blastoma (kids, benign cystic glands with malignant primitive stroma)

pleomorphic sarcoma

Question 5

benign mimics of malignancy

Answer 5

squamous metaplasia (vs SCC)

florid type II pneumocyte hyperplasia (vs malignancy)

hamartoma (vs bland ca/sarc)

meningothelial-like nodules (vs carcinoid)

sclerosing pneumocytoma/’haemangioma’

Question 6

Answer 6

Sclerosing pneumocytoma:

papillary, solid, sclerosed or angiomatous

cuboidal surface cells, round stromal cells

EMA, TTF1+

surface cells CK+

Question 8

malignant mimics of benign

Answer 8

subtle metastases (eg lobular ca)

malignancy obscured by inflammation

Question 9

almost normal

Answer 9

SECRET ALV

sequestration

emboli: fat, amniotic fluid, marrow, brain, liver, foreign body

CMV

RB

emphysema

pulmonary hypertension

amyloid

lymphangioleiomyomatosis (SMA, HMB45+)

vasculitis

Question 10

neuroendocrine tumours

Answer 10

typical carcinoid: <2 mit/2mm2, no necrosis (tumorlet if = 5mm)

atypical carcinoid: 2-10 mit/2mm2, punctate necrosis

large cell neuroendocrine ca: >10 mit/2mm2, large necrosis, organoid with palisades and/or rosettes, lower NC ratio

small cell ca: >10 mit/2mm2, large necrosis, molding, crush artefact, size less than 3 lymphocytes

Question 11

AAH vs AIS vs MIA/adenoca

Answer 11

AAH (usu has ca too): <5mm, mildly atypical pneumocytes, ‘peg like’

AIS: lepidic growth, no invasion, septal sclerosis common

MIA: = 3cm, <5mm invasion (and no LVI, necrosis or STAS)

NB: these are all RESECTION ONLY. If biopsy, call ‘lepidic growth’ only.

NB: if >3cm, call lepidic predominant adenoca

Question 12

Answer 12

Pulmonary blastoma (basal nuclei, clear cytoplasm)

Question 13

Answer 13

Pleomorphic (spindle and giant cell) carcinoma

Question 14

Answer 14

Basaloid carcinoma

Question 15

Answer 15

Bronchial mucous gland adenoma

Question 16

primary lung vs thymic ca

Answer 16

thymic: CD5, CD117+

Question 21

eosinophilic reactions

Answer 21

simple eosinophilia (no reaction)

acute eosinophilic pneumonia (DAD)

chronic eosinophilic pneumonia (organising DAD and organising pneumonia)

allergic bronchopulmonary aspergillosis (allergic mucin +/- aspergillus in large bronchi)

bronchocentric granulomatosis (granulomas only in bronchioles, related to CEP/ABPA)

Question 22

DDX for bronchocentric granulomas

Answer 22

bronchocentric granulomatosis

TB

fungal

Wegener granulomatosis

rheumatoid nodule

cystic fibrosis

Question 23

eosinophils

Answer 23

idiopathic

drugs

infection: aspergillus, parasites
inflammation: asthma, Churg-Strauss
neoplasms: LCH, mastocytoma, lymphomas

Question 24

granulomas

Answer 24

infection

drugs

foreign body

sarcoid

hypersensitivity pneumonia

vasculitis (Wegener, Churg-Strauss)

collagen vascular disease (SLE, RA)

bronchocentric granulomatosis

malignancy

Question 25

granulomatous infections

Answer 25

TB

MAIC (hot tub lung, small bronchioles)

fungal

parasites

Question 26

granulomatous foreign body

Answer 26

always polarise!

aspiration pneumonia

IV drug users

talc, silicon, aluminium, beryllium

Question 27

histiocytes

Answer 27

MAIC

Whipples

malakoplakia

DIP/RB

lipoid pneumonia

Rosai-Dorfman

LCH

lymphoma

Question 28

Aspergillus infections

Answer 28

aspergilloma: colonisation of existing cavity

ABPA: ILD, may not see fungi

acute invasive aspergillosis: invades vessels

Question 29

infections

Answer 29

CMV
measles

TB/MAIC

Aspergillus

Histoplasma (necrotising granuloma)

Cryptococcus (granuloma, mucicarmine+)

Pneumocystis (frothy pink material in alveoli, GMS+ cf diffuse alv proteinosis: PAS+)

Toxoplasma (GMS, giemsa+)

Question 30

lymphoid infiltrate

Answer 30

LIP: dense mononuclear, along septa

nodular lymphoid hyperplasia

follicular bronchitis/bronchiolitis

BALT lymphoma: confluent monotonous cells

lymphomatoid granulomatosis: necrosis, angioinvasive, large atypical CD20/EBV+ cells

other lymphomas (esp DLBCL)

Question 31

ILD - histologic patterns

(report these, clinical terms in bracket)

Answer 31

DAD (AIP)

organising pneumonia (COP)

UIP (idiopathic pulmonary fibrosis) - look for asbestos bodies

NSIP

DIP

LIP

RB (RB-ILD)

Question 32

Before calling idiopathic, exclude…

Answer 32

infection

sepsis

shock

inhalants

drugs

radiation

autoimmune disorders

Question 33

haemorrhage

Answer 33

antibody mediated: Goodpasture (anti BM IgG, linear IgG on DIFL)

immune complex mediated: SLE (‘full house’ on DIFL)

pauci immune: Wegener (c-ANCA), MPA (p-ANCA)

idiopathic pulmonary haemosiderosis

Question 34

clear cell lesions

Answer 34

clear cell/sugar tumour

clear cell SCC

mets: RCC, ACC, seminoma