Transcript Mohs micrographic surgery SWAG network service

Mohs micrographic surgery
SWAG network service
Update May 2016
Dr Adam Bray
Consultant Dermatologist
Dermatological & Mohs surgeon
Bristol
Bristol Mohs service
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Since Feb 2015
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Approximate waiting list 3 months once seen (less for eyelids)
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Second Mohs surgeon Dr Pawel Bogucki
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Excellent links with local Plastic surgery, Oculoplastics, and Maxillofacial
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Southmead Hospital, North Bristol NHS Trust (NBT)
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Any interested clinicians are welcome to arrange a visit for their professional
development
Referrals
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Please write to me stating:
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‘Referral for Mohs surgery, Dermatology
department’:
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Southmead Hospital, North Bristol Trust
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[email protected]
Bristol Mohs service
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110 cases treated (now usually 4 per week)
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Mainly Bristol
Secondary
intention or partial
closure
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Also Bath, Swindon, Cheltenham & Gloucester
Linear
Flap or graft or
combination
First 81 cases analysed
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Defect size mean
= 29mm
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Tumour size mean
= 22mm
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91% reconstructed by Dermatology (rest Plastics, and Oculoplastics)
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Almost all on the same day
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3 all day GA combined cases (Plastics, Oculoplastics, Mohs)
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Combined Oculoplastic list for eyelid cases every 1-2 months
What needs Mohs?
Tumours that can be easily excised with a sufficiently wide margin to
guarantee cure without significantly affecting the repair do not need Mohs.
A 'rule of thumb' is as follows:
- Can I confidently excise the tumour with the recommended
clinical margin & repair optimally?
- If not, Mohs (or other margin controlled surgery) should be
considered
On the SWAG
website
Possible Indications for Mohs (in order of strength)
 Poorly defined borders
 Anatomical location:
- ‘H-zone’ (high risk of recurrence)
- Sites where sparing tissue highly important
 Recurrent
 Incompletely excised
 Infiltrative/Morphoeic
 Large (>2cm)
 Immunosuppressed/Gorlin syndrome
N.B. Mohs is usually used for head and neck BCC, but other
sites and tumours can be considered.
N.B. Strongly consider Mohs for recurrent or incompletely excised tumours, unless
straightforward to take generous deeper layer, or skin margins of 6-10mm+ (for recurrences) or
4-6mm+ (for positive margins) as recommended for standard excision/pathology.
Situations where Mohs is difficult
1.If a GA is unavoidable
2.If bone is involved (but Mohs can still be useful to clear skin)
3.Consider other margin controlled surgery e.g. ‘spaghetti
technique’
The “spaghetti technique”: An alternative to Mohs surgery or staged
surgery for problematic lentiginous melanoma (lentigo maligna and acral
lentiginous melanoma).
J Am Acad Dermatol. Elsevier Inc; 2011 Jan 1;64(1):113–8.
Summary of Key Mohs Benefits
1.Maximum cure rate
2.Healthy tissue sparing potential
3.Fast results
What needs Mohs?
Consider Mohs over delayed repair
Why? The pathology is FAR more accurate
Avoid intra-operative frozen section analysis
Why? Shown to be VERY inaccurate
False-negative rate of intraoperative frozen section margin analysis for complex head and neck
nonmelanoma skin cancer excisions
M. D. Moncrieff, A. K. Shah, L. Igali, J. J. Garioch
Volume 40, Issue 8, pages 834–838, December 2015
Mohs Micrographic Surgery
Q. Why are tumours incompletely excised?
A.
-Because they are difficult to see
-Because they grow unpredictably
Q. Why do tumours recur?
A. Because they were not fully removed
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Thanks for listening
Referrals
•
Please write to me stating:
•
‘Referral for Mohs surgery, Dermatology
department’:
•
Southmead Hospital, North Bristol Trust
•
[email protected]
What needs Mohs?
Tumours that can be easily excised with a sufficiently wide margin to
guarantee cure without significantly affecting the repair do not need Mohs.
A 'rule of thumb' is as follows:
- Can I confidently excise the tumour with the recommended
clinical margin & repair optimally?
- If not, Mohs (or other margin controlled surgery) should be
considered
End
The Mohs procedure
explained
Mohs Micrographic Surgery
Pathology – nodular BCC
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Mohs Micrographic Surgery
Pathology – Micronodular BCC
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Mohs Micrographic Surgery
Pathology – Infiltrative BCC
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Mohs Micrographic Surgery
BCC Spread Beyond Clinical Margins
BCC Type
<20mm & Well-defined
Morphoeic
Clinical Excision
Margin Around
Tumour
3mm
Complete
Clearance Rate
(not cure)
85%
4mm - 5mm
95%
3mm
66%
5mm
82%
13mm – 15mm
>95%
Determined by Mohs pathology.
Breuninger H, Dietz K. Prediction of subclinical tumor infiltration in basal cell carcinoma. J Dermatol Surg Oncol
1991; 17:574–8.
Kimyai-Asadi A, Goldberg LH, Peterson SR et al. Efficacy of nar- row-margin excision of well-demarcated
primary facial basal cell carcinomas. J Am Acad Dermatol 2005; 53:464–8.
Telfer N, Colver G, Morton C. Guidelines for the management of basal cell carcinoma. Br J Dermatol. 2008 Jul.
1;159(1):35–48.
Of 75
Standard Pathology
Standard protocol
Usually 4-6 x3mm slices
5 micron shaves from each slice
Usually <5% of margins seen
Mohs Micrographic Surgery
Standard Pathology
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Mohs Micrographic Surgery
The Mohs Excision – Cross Section
PRESSURE DOWNWARDS
SQUASHED FLAT
UNDERSIDE OF SPECIMEN
100% OF MARGINS ON 1 PLANE
Superficial Peripheral Margin
Deep Margin
Deep Peripheral Margin
Mohs Micrographic Surgery
Mohs: Flattening the specimen
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