Management of Residual Spitz Nevus in Surgical Specimens following Biopsy and Excision

BACKGROUND: Proper management of Spitz nevi continues to be debated, with treatment ranging from observation to surgery. To better characterize the outcome of surgical procedures performed for incomplete initial excision or biopsy, we sought to ascertain the histopathological presence of residual Spitz nevi in a set of surgical specimens. METHODS: We retrospectively reviewed 123 records with histologically-confirmed Spitz nevus. Data concerning treatment, clinical features, histopathological margin involvement, and presence of residual lesion on subsequent procedural specimens were collected. RESULTS: Fifty-three percent of lesions (n = 65) were initially sampled by shave or punch biopsy, and the remainder (n = 58) were formally excised without initial biopsy. The rates of re-excision for involved margins were: shave biopsy (92.2%), punch biopsy (78.6%), and formal excision (13.8%). In total, 61.0% of patients who underwent an initial procedure of any kind had involved margins, but only half of those re-excised for involved margins (57.6%) had histologically residual lesion on repeated excision. A significantly higher proportion of initial punch biopsies (90.9%) resulted in residual lesion (in secondary excision specimens) when compared with shave biopsy (48.9%) and formal excision (62.5%; P < 0.05). CONCLUSIONS: Findings suggest that clinicians may consider shave biopsy over punch biopsy for diagnosing suspected lesions, when indicated and appropriate. Given the rarity of malignant transformation and the frequency of residual nevus, observation may be reasonable for managing pediatric patients with histologically-confirmed Spitz nevi, who are post initial biopsy or excision despite known histopathological margin involvement.