Surgery is considered the first line treatment for LM; however, it is not without associated morbidity. Wide surgical margins, especially on cosmetically-sensitive areas such as the face, are not always possible to obtain, and become further complicated when trying to maintain adequate functional and aesthetic outcomes. The margins required for surgical clearance may not be straightforward for facial lesions. A study by Hazan et al. reviewed 117 cases of LM and LMM and found that the total surgical margin required for excision of LM was 7.1 mm and for LMM was 10.3 mm. Moreover, of the tumors that were initially diagnosed as LM on biopsy, 16 % were found to have unsuspected invasion [26].

As surgical excision remains the standard of care for LM, it is important to optimize surgical methods and because there may be extensive subclinical extension, there is a need for better pre-treatment margin evaluation in LM. RCM is emerging as an adjunct to existing technologies, including dermoscopy and Wood’s lamp, to better delineate borders. Utilizing RCM pre-surgically offers the benefit of surgical planning, as it helps define the extent of subclinical spread prior to initiating the surgery. This informs both the surgeon and the patient to assist in reconstructive design and patient expectations. While RCM may be used to show that margins need to be increased due to subclinical spread, it may also allow for confirming narrower surgical margins in critical anatomical areas, facilitating reconstruction and decreasing patient morbidity. Thus, RCM provides valuable clinical information to potentially guide surgical management, and may lead to favorable cosmetic outcomes and a better prognosis.

One approach to using RCM to guide surgical management of LM is to first demarcate the lesion clinically with the aid of Wood’s lamp and dermoscopy, followed by placing appropriate surgical margins at 5–10 mm depending on clinical and histologic criteria. RCM may then be used within the lesion to identify features of the melanoma, thus serving as a control. An imaging “map” (Fig. 14.5) may be made by dividing the lesion into quadrants and capturing RCM video imaging along the periphery of surgical margins of each quadrant at the level of the dermoepidermal junction (main region to detect features of LM and LMM). In areas where positive findings including hyperreflective dendritic cells, large, round pagetoid cells, and epidermal disarray are seen, the margins are extended out radially. Video capture can be used to recreate video mosaics by stitching together sequences of images captured to re-create a larger field of view. As such, RCM is a valuable adjunct to the clinical exam and dermoscopy to determine clinical margins and define the gross tumor volume.

Advancements have been made in RCM technology, overcoming limitations of earlier iterations of the device. The newer, handheld Vivascope 3000 (Caliber ID, Rochester, NY) offers the advantage of real-time assessment in areas that may not have been amenable to previous versions of the device. Employing RCM during the initial consultation may help clinicians characterize subclinical spread of LM and therefore better counsel patients about the extent of their lesion. Additionally, Hibler et al. described the use of the handheld Vivascope 3000 intraoperatively to provide the surgeon with real-time assessment of tumor margins in vivo [27]. This may be a valuable approach for large cases of LM being performed in the operating room under general anesthesia, where the benefits of obtaining immediate visual confirmation of margins to ensure clearance may prevent a return trip to the operating room, saving costs and avoiding risks of additional anesthesia. Using RCM in this mapping fashion could ultimately allow for improved clearance of LM, thereby decreasing the likelihood of recurrence and the need for re-excision, while also maximizing tissue conservation and lowering morbidity.

While surgical excision is the treatment of choice for LM, factors including advanced patient age, multiple comorbidities, large lesion size in functionally or aesthetically-sensitive areas, and indiscriminate borders on photodamaged skin may make surgical excision complicated or not a feasible option. For patients unable to pursue surgical treatment and in cases where surgery would cause excess morbidity or deformity, multiple nonsurgical treatment options have been pursued. The use of superficial radiation or off label use of topical therapies, i.e. Imiquimod, has been reported in the literature as alternative non-surgical treatment options [28, 29]. However, the lack of histological confirmation, and possibility for undetected invasive spread have been limits to these modalities. Similarly, close monitoring for disease recurrence and progression is of utmost importance. Typically this is carried out by clinical examination, without adjunctive imaging beyond dermoscopy. RCM is emerging as an imaging technology that is proving useful to aid in the assessment of disease extent, treatment response and disease recurrence for LM after non-surgical therapy [1]. This is illustrated in Fig. 14.6.

In the same way that RCM may provide enhanced delineation of lesion margins for surgical intervention, it may also be capable of better defining a treatment field for radiation or topical therapies (Fig. 14.7). LMs treated with radiation or non surgical treatment modalities need close follow-up to detect recurrences [28]. Detecting recurrence can be a challenge clinically, as the lesion may recur as an amelanotic lesion, or can be further obscured by radiation-induced inflammation and post-radiation pigment changes. Because RCM allows for the same area of skin to be re-examined over time, this technology can also be applied to monitor for recurrence in LMs [30]. Changes in tissue architecture have been observed in LMs after radiation, including: superficial necrosis and apoptotic cells, dilated vessels, and increased inflammatory cells in both the dermis and epidermis [10]. After radiation, LM-specific large pagetoid cells were decreased or even resolved in the epidermis, dermal-epidermal junction, and in the follicles [10]. When using RCM to monitor for recurrence post-treatment, it is important to wait until the inflammation and post treatment changes have subsided to ensure any acute radiation-induced changes in skin architecture have resolved and will not cause false positives [31]. Epidermal regeneration post-radiation therapy begins 3–5 weeks after treatment and heals within 1–3 months, suggesting that radiation-induced changes on RCM might persist for this duration of time, although this has not been formally studied [32]. The ability to visualize and define changes during and after RT suggest RCM may be useful for monitoring for treatment failure. Examination with RCM may augment our ability to better define the radiation field pre-treatment and has been shown to be capable of detecting areas concerning for residual or recurrent disease post-treatment before clinical repigmentation [33].

In a similar manner, RCM may be utilized to monitor response after treatment with off label Imiquimod cream [34]. While the use of Imiquimod for LM has been well documented in the literature, the application, duration of therapy, and response to treatment vary greatly. Furthermore, factors accurately predicting a positive response to treatment have yet to be fully elucidated, as the degree of inflammatory response and erythema have not correlated well with overall clearance. The benefit of RCM after topical therapy is that it represents a non-invasive modality to monitor response to treatment and may help assess the need for increased duration of treatment. Moreover, similar to the changes induced post-radiation, treatment with Imiquimod may cause an alteration of the clinically apparent pigment, and it is therefore difficult to assess treatment success by clinical inspection alone. The use of RCM before, during, and after treatment provides a longitudinal assessment of the lesion, and may augment our ability to determine treatment success or failure.