Melanoma

What’s your strategy in managing this lesion?

  1. In 1970 the overall melanoma survival rate was less than 60%. Today the overall survival rate is over 90%. Much of this improvement in melanoma survival can be attributed to earlier diagnosis.
  2. Diagnosis of melanoma at earlier stages of evolution is, in part, due to increased awareness and increased surveillance.
  3. The notion that the in vivo diagnosis of melanoma is solely dependent on its clinical primary morphology derides the true complexity involved in diagnosing this malignancy. Components of the clinical examination used in the evaluation of skin lesions include touch, patient-derived anamnestic data, analytical reasoning (e.g., ABCD), comparative recognition (e.g, change), and differential recognition (e.g., ugly duckling sign).  The human cognitive process integrates this clinical information, extracting the pertinent information and rendering a diagnosis.
  4. Utilizing total body photography, dermoscopy, and dermoscopic short-term mole monitoring has contributed to the detection of many clinically subtle melanomas (improved sensitivity) and has also increased our diagnostic specificity. This translates into an improved ability to detect melanoma while concomitantly decreasing the number of unnecessary biopsies being performed on benign lesions.  Pigmented lesion experts utilizing baseline photography and dermoscopy remove approximately 5 benign nevi for every MM found. In contrast, non-experts remove as many as 30 benign nevi for every MM found.
  5. Future technologies such as confocal microscopy, computer vision, telemedicine, etc. are likely to continue to enhance the sensitivity and specificity for diagnosing early melanomas.

Maui Derm 2010: Surgical Management of Melanoma   K. Tanabe MD

In the surgical management of melanoma it is critically important to obtain adequate surgical margins. Ken Tanabe, oncology surgeon at MGH, discussed surgical margins for melanoma and the role of sentinel node biopsy and lymphatic mapping.  Recommended margins: melanoma in situ – 0.5 cm;  < 1 mm thickness – 1 cm;  1 – 2 mm thickness – 1 – 2 cm;  > 2 mm thickness – 2 cm.  These recommendations have been developed from the results of prospective randomized trials.  These margins may be modified to accommodate for anatomic or functional considerations in cases of melanomas of the face and hands.

In patients who are potential candidates for lymphatic mapping and sentinel node biopsy what does one need to know?   Dr Tanabe stated that while both offer clear advantages in enhancing accuracy of staging and regional disease control, their value in improving likelihood of long term survival remains a subject of debate. Sentinel node biopsy should be discussed with all patients with invasive, clinically localized melanoma before definitive wide local excision. Sentinel node biopsy should be considered in the following groups of patients with clinically localized melanoma > 1 mm Breslow thickness; < 1 mm Breslow thickness with positive deep margin, or > 1 mitoses, or ulceration. Patients with metastatic melanoma identified in their sentinel nodes should undergo completion lymphadenectomy, since approximately 20% of these patients will have additional (non-sentinel) nodes with melanoma. What can we offer our patients with advanced disease?  According to Dr Tanabe, in patients with hematogenous metastases, immunotherapy with IL-2 produces rare, but durable complete responses.  Conventional chemotherapy (e.g. dacarbazine) has limited activity.  Based on early trial results there is much interest in agents that target specific molecular pathways, such as Braf mutant tumors.