1. Write notes on the management of regional lymph nodes in melanoma under the following headings:
a) Lymph node biopsy in clinically susicious nodes (clinical stage III)
Melanoma patients who have palpable lymph node(s) either at their first presentation or at a follow up visit should have a sample taken for fine needle aspiration cytology (FNAC). If the first sample is unsatisfactory or negative with persistent suspicion, it should be repeated. If doubt persists an open biopsy can be performed. Evidence level 4
Palpable regional lymphadenopathy must be fully investigated in patients with primary melanoma.
If there is palpable lymphadenopathy FNAC should be used to obtain cytological confirmation of metastases.
If open biopsy is undertaken the incision must be placed in the same line as for a potential radical lymphadenectomy.
b) The place of elective node dissection
ELECTIVE LYMPH NODE DISSECTION
Although retrospective series126, 127, 128 suggest that resection of clinically non-involved lymph nodes provides a survival advantage in melanomas of intermediate thickness, this has not been confirmed in RCTs.129, 130, 131 Evidence level 2+
The Intergroup Surgical Melanoma Trial132 identified a small subgroup of patients with a possible survival advantage following elective lymph node dissection. This subgroup consisted of patients <60 years with non-ulcerated melanomas of 1 to 2 mm thickness situated on limbs. Sentinel lymph node biopsy (see section 4.3.5) has replaced elective lymph node dissection as a method of staging the regional lymph node basin. Evidence level 1+
Elective lymph node dissection should not be routinely performed in patients with primary melanoma.
c) Therapeutic dissection of clinically positive nodes
THERAPEUTIC LYMPH NODE DISSECTION
Nodal involvement indicates an advanced stage of disease. Confirmation of metastatic melanoma in one node is an indication for radical dissection of that lymph node basin. The number of involved nodes is of prognostic significance. Ten year survival varies between 20 to 45% dependent on the extent of nodal involvement.9, 113, 118, 120
Therapeutic lymph node dissection is beneficial in controlling locoregional disease. The risk of recurrence in the dissected node field remains, particularly with head and neck melanomas.122, 123 Evidence level 2++
Groin nodes include a superficial group of inguinal nodes below the inguinal ligament and the obturator and iliac group of nodes which lie deeper in the pelvis. Ilioinguinal dissection offers a survival benefit in patients with palpable positive inguinal nodes compared with inguinal block dissection of the femoral triangle node.124, 125 Evidence level 2++
Head and neck melanomas have the most variable pattern of lymph node metastasis and require a variety of types of neck dissection that may include the parotid or the posterior occipital chain nodes.123
Radical lymph node dissection requires complete and radical removal of all draining lymph nodes to allow full pathological examination.
Regional lymph node dissection carries a well defined and significant morbidity and should be undertaken only by surgeons with appropriate expertise.
d) Lymphatic mapping and sentinel node biopsy
SENTINEL LYMPH NODE BIOPSY (SLNB)
The sentinel lymph node is defined as the first node in the lymphatic basin that drains the lesion and is the node at greatest risk for the development of metastasis.133 Biopsy of this node can assist in staging patients at risk of metastatic disease. Current practice is for patients with a positive sentinel node to proceed to radical node dissection.
The standard for sentinel node biopsy is a triple diagnostic approach of lymphoscintography; blue dye dermal infiltration and localisation using a hand held gamma probe.133, 134, 135, 136, 137, 138 Performing SLNB requires appropriate surgical expertise,133 specialist nuclear medicine services and the availability of serial sectioning and immunohistochemistry techniques (see section 3.5). Evidence level 2+
Sentinel lymph node biopsy accurately determines the presence or absence of metastasis within the regional lymph node basin139, 140, 141 and it is a useful staging tool in melanomas >1 mm.110 In thick melanomas (>4 mm) it can identify a subset of good prognosis melanomas which are node negative.141 Evidence level 2++,4
SLNB should be considered as a staging technique in patients with a primary melanoma >1 mm thick or a primary melanoma <1 mm thick of Clark level 4
Ref: http://www.sign.ac.uk/guidelines/fulltext/72/section4.html
