Long‐term clinical outcomes of Spitz‐type lesions in adults: A single institution retrospective cohort review

AbstractBackgroundThe lack of information on clinical outcomes of Spitz‐type lesions, means that their management remains a contentious issue, with some centres opting for a purely conservative, observational approach, while others mandate further surgery and long‐term follow‐up.ObjectivesOur aim was, therefore, to determine the long‐term clinical outcome of classic Spitz and Spitzoid naevi, atypical Spitz tumours (ASTs) and Spitzoid melanomas, with a view to finding evidence to support a unified management approach.MethodsWe conducted a retrospective cohort review of Addenbrooke's Hospital patients aged ≥18 years with a histopathologic diagnosis containing the term ‘Spitz’, from 1991 through 2020. Sentinel lymph node biopsy (SLNB) results, wide local excision (WLE) rates, metastases and fatality were assessed.ResultsOne hundred and twenty‐six patients with Spitz‐type proliferations and follow‐up information were identified (mean age: 35.9, SD: 11.6). There were 86 (68.3%) classic Spitz or Spitzoid naevi, 12 (9.5%) ASTs, 27 (21.4%) Spitzoid malignant melanomas and one (0.8%) melanoma that arose in a previously excised Spitz naevus. SLNB findings were positive in three of seven but none of the 10 individuals with ASTs and Spitzoid melanomas, respectively. Invasive non‐Spitz melanoma developed in four patients with classic Spitz or Spitzoid naevi. After a median follow‐up of 46 months (range: 1–304), only one patient with a Spitzoid melanoma, who had a different malignant melanoma (2.4 mm, level 4), developed distant metastases. No deaths were observed.ConclusionsSpitz‐type lesions are only rarely associated with mortality and distant metastasis, but CSNs may increase the risk of developing non‐Spitz‐type malignant melanoma. These findings support the suggestion that aggressive surgical management of these lesions such as SLNB and WLE may not be necessary, but surveillance should still continue to assess for subsequent development of malignant melanoma.