Head/neck/soft Tissue Flashcards
Describe the lymph node levels in neck? What are radical, modified radical and selective neck dissection?
There are 7 levels
- submental (1a) and submandibular (1b)
- Upper third of IJV (hyoid to base of skull (2a = anterior to XI nv; 2b = posterior to XI nerve)
- middle third of IJV (Hyoid to Cricoid)
- Lower third of IJV (Hyoid to clavicle)
- posterior to SCM (5a= above cricoid; 5b = below cricoid)
- Central (between carotids and innominate)
- Superior mediastinum
Radical neck dissection = removal of all fibrofatty tissue on levels 1 -5 plus SCM, IJV and XI nerve
Modified radical = all fibrofatty tissue in levels 1-5 but any or all of SCM, IJV and XI preserved
Selective neck dissection = dissection of all fibrofatty structures in a selected compartment, preserving all critical structures
what are the layers of epidermis?
Come, let’s go sun bath
C - stratum corneum
L - lucidum
G - granulosum
S - spinosum
B - basale
ABCDE of melanoma
A - asymmetry B - border C - colour D - Diameter >6mm E - Evolution
What are the high risk features melanoma
LN metastasis
Breslow thickness
Mitosis
Ulceration
Age (more is worse)
Gender (men worse)
What are risk factors for melanoma?
M-FRISKx
Moles (multiple, >50) - dysplastic naevus
F Freckles
R - race (whites) and red hair
I - Immunosuppressed
S - Sun damage
K - Kindred (fam history)
Xeroderma pigmentosum
What are the types of melanoma
Melanoma LANDS on the skin
L - lentigo maligna (head and face, late vertical phase growth)
A - Acral (subungal, feet, hands)
N - Nodular (early vertical phase, may be amelanocytic)
D - Desmoplastic (with stromal fibrosis, neurotrophic)
S - Superficial spreading (commonest)
What is Breslow thickness?
This measures the depth of the tumor cell invasion from stratum granulosum to the deepest point of invasion. It correlates with the prognosis and helps guide treatment. <1mm (thin) 1.1 - 3.9 mm (Intermediate. In MSLT1 - 1.2 -3.5 mm was designated intermediate) >4 mm (thick)
Indications and technique for SNB in melanoma
Indications: I use the melanoma institute sentinel node metastasis risk prediction tool to calculate the probability of melanoma having spread to the node. SNB is typically indicated if the risk is >10%; but decision needs to be tailored to individual patients.
In general terms, the results of MSLT1 trail confirms that SNB for intermediate thickness melanoma provides melanoma specific survival advantage. Performing SNB in very thin or thick melanoma is controversial. There is evidence that patients with thin melanoma >0.75mm may only benefit form SNB if they have high risk features. For thick Melanoma, SNB may help prognosticate but does not alter the final outcome.
Technique: Lymphoscintigraphy is performed pre-op to identify which basin to operate. Patent blue or isosulfan blue is injected intradermally around the lesion/scar after anaesthesia. Intraoperatively, hot and or blue node is then removed being careful not to remove more than 2-3 nodes. Frozen sections are usually not sent because of difficulty in diagnosing melanoma on frozen section.
What were the outcomes of MSLT 1 and MSLT 2 trials?
MSLT1 - 2001 patients with intermediate (1.2 - 3.5mm) melanoma and thick melanoma (>3.5mm) were randomised them into SNB vs observation for nodes. Results at 10-year show disease free survival advantage in intermediate group but not thick group. For intermediate melanoma 16% had a positive SNB and underwent lymphadenectomy. The melanoma specific survival advantage was only seen in these patients, not for the whole group of SNB.
MSLTII - 1934 patients with melanoma >1.2mm or Clark level 3-5 or ulceration and +SNB randomized to elective node dissection vs no further surgery. Interim results at 4.3yrs show melanoma specific survival to be same, disease-free survival better in node dissection group but also significant comorbidities (lymphedema 24% vs 6 %) in the same group. It has not been possible to isolate a specific group of patients who would benefit from CLND. For the observation group, surveillance was performed with US scans 4 monthly for 2 years, 6 monthly for 3-5 yrs and then annually. most patients had <1mm mets in the lymph node.
Findings of the MSLT II trial is echoed by the De-COG-SLT trial in which 483 patients with melanoma were randomised to receive CLND vs observation. There was no difference in the overall survival or metastasis free survival.
What structures are at risk during submandibular gland surgery?
Superficial to the gland
- Marginal mandibular nv
- cervical branch of VII nv
Superficial lobe
- Facial artery
- Facial V
Deep lobe
- Lingual nerve
- XII nerve
- Ranine vein
Describe the staging for cutaneous melanoma
All T stages subclassified a= no ulcer, b = ulceration
T1 - <1mm deep
T2 - 1-2 mm
T3 - 2-4
T4 >4
N1 - 1 (node or intransit met or satellite melanoma)
N2 - 2-3
N3 - 4 or more
Stage 1 (early local) = T1, t2a
Stage 2 (advanced local) = T2b - T4b, N0, MO
Stage 3 - Node positive (or intransit or satellite mets)
Stage 4 - metastatic
What are the adjuvant therapy options for melanoma
Depends on local protocols/ availability/ tumour characters.
Adjuvant therapy is indicated in stage 3 - 4 disease (nodes or mets)
Surgery
- Oligometastatic disease that is resectable (best outcome)
Targeted therapy
- **MAPK pathway - _(_BRAF+MEK - inhibitors if mutation present)
- KIT - inhibitors (If mutated)
Immune therapy
Immune checkpoint therapy - blocks natural checkpoint for T-cell productions thereby unleashes massive number of T cells. Combination of CTLA4 + PD1 is recommended.
- CTLA4 blockers - Ipilimumab (Yervoy)
- PD-1 blocker - Pembrozulimab (keytruda), Nivolumab (Opdivo)
Isolated limb infusion using Melphalan
- Papaverine used as vasodilator and heparin used as anticoagulant before melphalan infusion.
limited availability, no survival benefit but improves local control.
Radiotherapy
- Palliative control of local disease
Chemotherapy
- Limited role due to poor outcomes
What is hidradenitis suppurativa
It is a chronic inflammatory condition of the folliculo-pilo-sebaceous unit of the skin and is characterised by painful, nodular pustules with scarring and fistulation in the intertriginous areas of the body
What % of patients with Melanoma have positive SNB?
Intermediate thickness (1.2mm - 3.5mm)
- approx 20% will have lymph node mets
- SNB will identify approx 16-17 % patients
- 3-4% will have a false negative SNB
Thick melanoma (>3.5mm)
- approx 40 % will have a LN met
The risk can be predicted using the melanoma institute sentinel node metastasis risk prediction tool.
Factors affecting prognosis in metastatic melanoma
- LDH
- performance status
- < 3 sites with metastatic disease
