Primary cutaneous melanoma rarely affects the breast, accounting for less than 5% of all malignant melanomas [1, 2]. Several cases have been reported in the literature [2, 3]. It is highly probable that there is no significant difference between melanomas of the breast and melanomas arising from other cutaneous areas as far as correlation of Clark's level of invasion with prognosis and regional lymph node status is concerned [1, 3]. In general, operable cutaneous melanomas are treated with wide local excision. 1 cm clearance is adequate for lesions < 1 mm thick and a 2 cm margin for lesions up to 4 mm thick . There are few data to support the use of margins wider than 2 cms even in lesions > 4 mm thick . In our case the radial margin of over 1.0 cm was adequate as the lesion was < 1 mm thick. The presence or absence of metastases in the regional lymph nodes (RLN) is the most significant prognostic variable that predicts survival in patients with melanomas. It is extremely rare for it to spread systemically without first passing through the first draining lymph node basin . These neoplasia are felt to follow a different metastatic pattern than do primary carcinoma of the breast, and require a different therapeutic approach .
Papachristuo et al  found that lesions located below a 3 cm radius from the clavicle metastasised exclusively to the axillary lymph nodes regardless of sex or location. Further, in their 19 patients with central and medial lesions where internal mammary nodes were available for examination, none of them had disease in those nodes despite the fact that half of them had simultaneous axillary node metastases. Where the RLN are impalpable, their surgical assessment has been controversial and has varied from selective lymph node dissection to elective lymph node dissection (ELND). A major argument against ELND in all is that if all patients with high risk melanomas are subjected to ELND, 70–80% will receive an unnecessary surgical procedure as only 20–30% will have RLN metastases. The therapeutic benefit of removing clinically normal nodes has never been proven [7, 8]. Patients with thick melanomas (> 4.0 mm) have a high incidence of systemic disease and should undergo a proper extent of disease evaluation. Regional node assessment provides valuable staging and prognostic information , and for lesions located 3 cm from the clavicle , nodal assessment on the cervical region has been recommended. Assessment of regional nodes was not necessary in our case as the tumour was < 1 mm thick. Just over a decade ago regional nodes were assessed by complete lymph node dissection (CLND)  resulting in unnecessary surgery in many [9, 10]. However, the introduction of sentinel lymph node biopsy(SNLB) into surgical practice has revolutionized the assessment of regional nodes . Morton and colleagues were the first to demonstrate that lymphatic drainage from a melanoma can be "mapped" by injecting the skin around the tumour with blue dye. Injected blue dye was shown to travel through lymphatic channels to the first, or "sentinel" lymph node (SLN) that drains the tumour. It was shown that histological examination of the SLN accurately reflected the pathological status of the entire regional lymph node basin. A positive SLN is associated with a higher chance of the remaining nodes containing metastases, while patients with negative SLNs infrequently have other nodes that contain tumour cells [9, 10]. SLN mapping, therefore, spares approximately 80–85% of patients with melanoma from having CLND for what will ultimately be a negative regional nodal basin [9, 10].
Patients with melanomas most likely to benefit from SLNB have thickness of 1–4 mm  as the incidence of nodal metastases ranges from 6% for patients with 1 mm melanomas to 35% in patients with 4 mm melanomas [10, 11]. For patients with melanomas less than 1 mm, the indications for SLNB would be Clark level IV depth, presence of tumour regression, and ulceration . Young age, higher number of mitoses, male gender and axial location are viewed as some of the relative indications . The third interim analysis of the Multicentre Selective Lymphadenectomy Trial (MSLT-1) on SLNB shows that melanoma patients who had wide excision followed by selective lymph node dissection had a survival similar to patients where a watch and wait policy had been followed, with complete lymph node dissection in case of pathological lymph node involvement. In this study the disease free survival was superior after SLNB .