Transcript A Talk About Bowels And Other Interesting Organs

Special polyp types
Professor Neil A Shepherd
Gloucester, UK
NHSBCSP Pathology Day,
London, November 21, 2007
Pathology and the NHSBCSP
• a polyp is any lesion raised above the level of an
epithelial surface
• suddenly, with BCSP, there are lots more
colonoscopies
• all done by experts with dye-spray of small lesions
and EMR
• we might expect to see the occasional funny and we
need to be alert
A classification of polyps of the colorectum
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•
•
•
•
•
•
adenomas
hyperplastic polyps
mixed polyps
inflammatory polyps
juvenile polyps
Peutz-Jeghers polyps
stromal polyps
• syndromic polyps – the triumvirate of polyposes,
Cowden’s, Cronkhite-Canada, etc
Morson & Dawson, 2003
A classification of polyps of the colorectum
•
•
•
•
•
•
•
adenomas
hyperplastic polyps
mixed polyps
inflammatory polyps
juvenile polyps
Peutz-Jeghers polyps
stromal polyps
• syndromic polyps – polyposes, Cowden’s, CronkhiteCanada, etc
• but some ‘polyps’ likely to be excised in BCSP are
not in the list…..
68M. Polypoid nodule in rectum.
chromogranin
synaptophysin
Gloucestershire BCSP, January-October 2007
normal
30
19.87%
cancer
24
15.89%
low risk polyps
20
13.25%
intermediate risk
polyps
38
25.17%
high risk polyps
22
14.57%
abnormal result, not
polyps
6
3.97%
refer for surgery
(polyp)
5
3.31%
miscellaneous
6
3.97%
TOTAL
151
100%
A classification of polyps of the colorectum
•
•
•
•
•
•
•
adenomas
hyperplastic polyps
mixed polyps
inflammatory polyps
juvenile polyps
Peutz-Jeghers polyps
stromal polyps
• syndromic polyps – polyposes, Cowden’s, CronkhiteCanada, etc
Morson & Dawson, 2003
Hyperplastic polyps
• about 25% of all polyps
Issues:
• differentiating them from mixed polyps & serrated adenoma
• when they are large and right-sided and show SSP features
• when they show epithelial misplacement – inverted
hyperplastic polyps
Inverted hyperplastic polyps
• closely related to right sided SSPs
Shepherd, 1991
A classification of polyps of the colorectum
•
•
•
•
•
•
•
adenomas
hyperplastic polyps
mixed polyps
inflammatory polyps
juvenile polyps
Peutz-Jeghers polyps
stromal polyps
• syndromic polyps – polyposes, Cowden’s, CronkhiteCanada, etc
Morson & Dawson, 2003
Inflammatory polyps
• the most common ‘other’ entity in BCSP
• most are single/scanty and not related to CIBD (UC, CD, chronic
infection such as schisto)
• in the age group of the BSCP population, diverticulosis-associated
polyps, polypoid mucosal prolapse, post-interventional polyps more
common
67F. BCSP. Diverticulosis and sigmoid colonic polyp.
Polypoid mucosal prolapse
• in the BCSP age group, lower
rectal/anal most common:
inflammatory cloacogenic
polyp
• epithelial (villous) hyperplasia
traps the unwary into calling
them large villous adenomas
• may be seen in association
with diverticulosis, at
stomas, in SUMPS, etc
Polypoid mucosal prolapse at the anorectal
junction
• a word of warning with inflammatory cloacogenic
polyp
• 4 cases of adenomas of the lower rectum causing
secondary polypoid mucosal prolapse
Parfitt & Shepherd, 2008
a
c
b
Ki-67
d
p53
a
c
b
Ki-67
d
p53
A classification of polyps of the colorectum
•
•
•
•
•
•
•
adenomas
hyperplastic polyps
mixed polyps
inflammatory polyps
juvenile polyps
Peutz-Jeghers polyps
stromal polyps
• syndromic polyps – polyposes, Cowden’s, CronkhiteCanada, etc
Morson & Dawson, 2003
Juvenile polyps
• commonest polyp in childhood
• sporadic juvenile polyps do occur in adulthood but very rare in
BCSP age group
• inflammatory polyps can look similar
• pretty unlikely to see juvenile polyposis….
Juvenile polyposis
‘Atypical juvenile polyps’ with dysplasia
Juvenile polyposis
• 1 in 80,000
• genetics becoming clearer but polymorphic: SMAD4 implicated in 25%
• high rates of colorectal cancer: life time risk - ? up to 30%
• dysplasia in atypical juvenile polyps
• ? surveillance ? prophylactic colectomy
Jass et al 1988,
Woodford-Richens et al, 2000
Quick quiz question
SMAD 4 mutation is implicated in about a quarter of
cases of this condition. What does SMAD stand
for? Is it:
1. somatic mutation in Arctic drosophila
2. serine-methionine-arginine deletion
3. small mothers against decapentaplegia
Quick quiz question
SMAD 4 mutation is implicated in about a quarter of
cases of this condition. What does SMAD stand
for? Is it:
1. somatic mutation in Arctic drosophila
2. serine-methionine-arginine deletion
3. small mothers against decapentaplegia
A classification of polyps of the colorectum
•
•
•
•
•
•
•
adenomas
hyperplastic polyps
mixed polyps
inflammatory polyps
juvenile polyps
Peutz-Jeghers polyps
stromal polyps
• syndromic polyps – polyposes, Cowden’s, CronkhiteCanada, etc
Morson & Dawson, 2003
Peutz-Jeghers polyposis
Peutz-Jeghers polyps
• syndrome about 1 in 100,000
• sporadic PJ-like polyps
described but very rare
• ? relationship to ‘inflammatory
myoglandular polyp’
• aren’t sporadic PJPs most
likely to be post-inflammatory
or post-mucosal prolapse?
Do sporadic Peutz-Jeghers polyps exist?
• 119 polyps in 38 patients
• most patients with PJ-like polyps were actually shown to have
PJS (scanty colonic polyps in the syndrome)
• 8 left: three small bowel ones with PJ features; 5 colonic with
suggestive features of PJPs (top GI pathologists could not tell
for certain: mucosal prolapse could not be excluded). 40% in
BCSP screening age group
• if they exist, sporadic colorectal PJ polyps are very rare
Burkhart et al. Do sporadic Peutz-Jeghers polyps exist?
Experience from a large teaching hospital. AJSP, August 2007
A classification of polyps of the colorectum
•
•
•
•
•
•
•
adenomas
hyperplastic polyps
mixed polyps
inflammatory polyps
juvenile polyps
Peutz-Jeghers polyps
stromal polyps
• syndromic polyps – polyposes, Cowden’s, CronkhiteCanada, etc
Morson & Dawson, 2003
Stromal polyps
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•
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GIST
leiomyoma of muscularis mucosae
gastrointestinal schwannoma
neurofibroma
ganglioneuroma
epithelioid mucosal nerve sheath tumour
intestinal perineurioma
fibroblastic polyp
inflammatory fibroid polyp
that’s enough stromal polyps (Ed)
Small polypoid rectal nodules
Gastrointestinal schwannoma
•
33 cases: 4 oesophagus, 24 stomach, 2 colon and 3 rectum
•
mainly within muscularis propria and/or subserosa
•
none encapsulated but all well circumscribed
•
32/33 cuff of lymphocytes
•
only 12 originally called schwannoma
•
S100 and vimentin +ve
•
CD117, CD34, ASMA, desmin –ve
•
nestin 80% positive; GFAP 64% positive
•
all showed some nuclear pleomorphism: ? longevity: no mitoses
•
all benign
Hou et al, 2006 (Histopathology)
Colonic polypoid mucosal lesions with mucosal
entrapment and epithelial serration
A feature only rarely seen in GISTs
Colorectal intramucosal tumours with epithelial ‘entrapment’
Name
First
recognised
S100
CD 34
EMA
Epithelial
serration
Clinical
features
neurofibroma
The year
dot
+ ve
-ve
- ve
occasionally
Most
solitary but
@ NF
ganglioneuroma
probably
down to
Carney…
+ve
-ve
-ve
not
described
sporadic
or NF-1,
MEN 2b
benign
fibroblastic
polyp of
colon
2004
- ve
+ve
- ve
3/13
none
intestinal
perineurioma
2005
- ve
-ve
+ ve
5/9
none
epithelioid
NS tumour
2005
+ve
+/-ve
-ve
0/6
none
Benign fibroblastic polyp of colon:
Eslami-Varzaneh F, Washington K, Robert ME, Kashgarian M, Goldblum JR,
Jain D. AJSP 2004; 28: 374-378.
CD34 positive: ‘neural’ markers negative
Intestinal perineurioma:
Hornick JL, Fletcher CDM. AJSP 2005; 29: 859-865.
EMA positive: CD 117, CD 34, S100 negative
Mucosal epithelioid nerve sheath tumour:
Lewin MR, Dilworth HP, Alfa AK, Epstein JI, Montgomery E.
AJSP 2005; 29: 1310-1315.
S 100
CD 34
S100 & CD 34 positive: EMA & CD 117 negative
Colorectal intramucosal tumours with
epithelial ‘entrapment’ and surface serration
• extraordinary ‘new’ descriptions of three entities – smallish spindle cell
polypoid tumours with epithelial entrapment and surface epithelial
serration
• ? recent recognition due to legislation to allow Medicare customers to
undergo screening colonoscopy (2001)
• lesions are mainly of schwann cell/perineural cell origin
• differentiation by immunohistochemistry although specificity of these
entities is a little doubtful..
Zamecnik & Chlumska, 2006
Groisman et al, 2006
• all are benign and should not be confused with more sinister lesions such
as GISTs and others
Take home messages: special polyp types
• inflammatory polyp/polypoid mucosal prolapse most
common after adenomas and HPs
• remember other lesions can be polypoid – leiomyoma
of mm and rectal carcinoid – clinical, endoscopic and
imaging correlation important
• the ‘hamartomatous’ polyps and syndromes are very
rare (but not unheard of) in the BCSP age group
• serrated change can be a secondary phenomenon
(polypoid mucosal prolapse, fibroblastic polyps, etc)