Atypical Spitz Tumors: An epidemiological, clinical and dermoscopic multicenter study with 16‐year follow‐up

Pediatric spitzoid lesions of the ear: a single-center experience and review of the literature

Spitzoid lesions are challenging melanocytic lesions comprising benign, intermediate, and malignant lesions. In this study, we aimed to analyze the diagnostic accuracy of clinical and dermatoscopical evaluations of pediatric spitzoid ear lesions. We collected and analyzed, clinically, dermatoscopically, and histologically, pediatric spitzoid ear lesions. We also conducted a systematic review of the literature. At the Pediatric Hospital Gaslini, excision and histopathological evaluation were performed on eight cases: 87.5% of the lesions were consistent with Spitz nevus (SN), and 12.5% with atypical Spitz tumor (AST). Notably, multiple (≥2) dermatoscopical irregularities were present in 5 of 7 SN (71%), yet none were found in AST (0%, 0/1) (Fisher's exact test, P=0.375). From systematic research in the literature, 9 patients were included in this review. At histology, 88.9% were SN and 11% AST. Remarkably, also in the literature, multiple dermatoscopical irregularities were present in most SN (75%, 6/8), but not in the identified AST (0%, 0/1) (P=0.3333). We present a monocentric study on pediatric spitzoid ear lesions. Importantly, dermatoscopical irregularities were not significantly associated with AST, neither in our series nor in the reviewed literature (respectively P=0.375 and P=0.3333), supporting the fact that relying only on the dermatoscopical aspect of spitzoid lesions is not accurate enough for the special site of the ear, where dermatoscopy could actually be misleading.

Paediatric Spitzoid Neoplasms: 10-Year Retrospective Study Characterizing Histological, Clinical, Dermoscopic Presentation and FISH Test Results

INTRODUCTION

Spitzoid lesions are a wide tumour class comprising Spitz nevus (SN), atypical Spitz tumour (AST) and Spitz melanoma (SM).

MATERIALS AND METHODS

We conducted a single-centre-based retrospective survey on all histologically diagnosed spitzoid lesions of paediatric patients (1-18 years) of the last 10 years (2012-2022). Histopathological reports and electronic records of patients were used to retrieve relevant data regarding patients' features, clinical and dermatoscopical aspects of lesions when recorded, and FISH tests when present.

RESULTS

Of 255 lesions, 82% were histologically benign, 17% atypical, 1% malignant. Clinically, 100% of SM were large (≥6 mm) and raised; AST were mainly large (63%), raised (98%), pink (95%). Small (≤5 mm), pigmented, flat lesions correlated with benign histology (respectively 90%, 97%, 98% SN) (p < 0.0001). Dermatoscopical patterns were analysed in 100 patients: starburst pattern correlated with benign histology (26% SN (p = 0.004)), while multicomponent pattern correlated with atypical/malignant lesions (56% AST, 50% SM (p = 0.0052)). Eighty-five lesions were subjected to fluorescence in situ hybridization (FISH): 34 (71% AST; 29% SN) were FISH-positive; 51 (63% SN; 37% AST) were FISH-negative (p = 0.0038).

DISCUSSION

This study confirmed predominant benign histology (82%) of paediatric spitzoid lesions, thus detecting 17% AST and 1% SM, highlighting the need for caution in handling spitzoid lesions.

CONCLUSION

Until AST are considered potentially malignant proliferations and no reliable criteria are identified to distinguish them, the authors suggest a prudent approach, especially in children.

The Spectrum of Spitz Melanocytic Lesions: From Morphologic Diagnosis to Molecular Classification

Spitz tumors represent a distinct subtype of melanocytic lesions with characteristic histopathologic features, some of which are overlapping with melanoma. More common in the pediatric and younger population, they can be clinically suspected by recognizing specific patterns on dermatoscopic examination, and several subtypes have been described. We now classify these lesions into benign Spitz nevi, intermediate lesions identified as “atypical Spitz tumors” (or Spitz melanocytoma) and malignant Spitz melanoma. More recently a large body of work has uncovered the molecular underpinning of Spitz tumors, including mutations in the HRAS gene and several gene fusions involving several protein kinases. Here we present an overarching view of our current knowledge and understanding of Spitz tumors, detailing clinical, histopathological and molecular features characteristic of these lesions.

Conceptual Evolution and Current Approach to Spitz Tumors

Over the past several decades, the study of Spitz neoplasms has flourished, with expanded conceptualization and refined terminology, providing a framework for the assessment and classification of Spitz nevi, atypical Spitz Tumors, and Spitz melanoma. Cancer genomics have generated concepts such as driver and passenger genes and clonal evolution, which can be applied to Spitz tumors. Herein, we provide a historical perspective, followed by a summary of current knowledge and clinical approaches for these challenging tumors.