From the Guidelines
Further workup is not necessarily recommended for a compound melanocytic nevus with mild atypia found on shave biopsy, as routine reexcision to negative margins may be unnecessary, with several small-scale studies documenting low short-term recurrence rates and no progression to melanoma. According to the study by Kmetz et al. 1, patients with biopsy-proven atypical nevi who were followed up for 5 years or longer showed no occurrence of melanoma, even when nearly half had involved biopsy margins. Another study evaluated 195 dysplastic nevi with mild to moderate atypia with a 2-year follow-up, reporting a 3.6% local recurrence rate, which was not associated with melanoma 1.
Key points to consider in the management of such cases include:
- The presence of mild atypia, which represents cellular irregularities that are not definitively cancerous but warrant closer examination to rule out more serious pathology
- The potential for shave biopsies to miss areas of greater atypia or early melanoma due to incomplete sampling of the lesion's depth
- The importance of balancing the need for adequate diagnosis with the avoidance of overly aggressive treatment for what is likely a benign condition with minimal malignant potential
- The role of regular skin examinations every 6-12 months to monitor for any new or changing lesions, with the follow-up schedule adjustable based on personal risk factors such as family history of melanoma, previous skin cancers, or numerous atypical nevi.
In cases where the margin-positive lesion is the only one of its kind, conservative reexcision (2–5 mm) may be considered, as suggested by the authors of the study 1, although long-term data are still lacking, particularly for patients with severe or high-grade dysplasia.
From the Research
Compound Melanocytes Nevis with Mild Atypical on Shave Biopsy
Should Further Work Up Be Done
- The decision to perform further workup on a compound melanocytes nevis with mild atypia on shave biopsy depends on various factors, including the presence of clear margins and the degree of atypia 2, 3.
- A study published in the Journal of Cutaneous Medicine and Surgery found that dysplastic nevi with moderate or severe atypia and clear margins on shave removal specimens are most likely completely excised, with a negative predictive value of 98.4% 2.
- Another study published in Dermatologic Surgery found that shave re-excision had a lower clearance rate (76.2%) compared to surgical excision (87.5%) for atypical nevi with positive margins 3.
- However, a study published in the Journal of the American College of Surgeons found that shave biopsy is a safe and accurate method for the initial evaluation of melanoma, with accurate T-staging and minimal impact on definitive surgical treatment and outcomes 4.
- In the case of a compound melanocytes nevis with mild atypia, the risk of melanoma is relatively low, and further workup may not be necessary if the margins are clear and there are no other concerning features 5, 6.
- The American Journal of Dermatopathology published a study on polypoid compound melanocytic proliferations, which can exhibit a spectrum of junctional architectural and cytologic atypia, but are often benign 6.
- It is essential to consider the individual case characteristics, including the degree of atypia, margin status, and patient factors, when deciding whether to perform further workup or surveillance 2, 3, 4.