Dermatology · Oncology · 2 h ago
Stepwise Review Classifies Most Ambiguous Melanocytic Tumors
In a prospective cohort at a Dutch tertiary dermatopathology center, expert histopathology and additional molecular testing yielded a diagnosis for 97.2% of 994 patients with ambiguous primary cutaneous melanocytic tumors. Follow-up findings supported the clinical validity of the classifications, though the study was conducted in a specialist referral setting.
- A diagnosis was reached in 966 of 994 patients.
- Molecular analyses contributed to 549 diagnoses.
- No melanoma-related events occurred in the nonmelanoma group.
- The cohort was assessed at a specialist referral center.
Researchers prospectively evaluated consecutive patients referred to a tertiary dermatopathology center in the Netherlands from September 2018 through December 2021 after their primary cutaneous melanocytic tumors were deemed ambiguous by referring pathologists. The stepwise assessment began with expert histopathology; tumors that remained inconclusive underwent molecular analyses, including next-generation sequencing, single-nucleotide polymorphism array, and targeted RNA sequencing. The team assessed diagnostic yield and melanoma-related events during follow-up.
Of 994 patients, 966 (97.2%) received a diagnosis: 417 (42.0%) after expert histopathology alone and 549 (55.2%) after additional molecular analyses. Among 608 patients classified as having nonmelanoma, no melanoma-related events occurred during a median 5.4 years of follow-up (95% CI, 0.0 to 0.6%). Among 358 classified as having melanoma, 20 developed melanoma-related events over a median 5.0 years; 33 of 186 who underwent sentinel node biopsy had a positive result. No events occurred among 28 patients classified as having borderline melanoma.
The findings support the diagnostic validity of combining expert review with molecular testing when initial histopathology is inconclusive. Applicability may be limited outside specialist referral settings, and the cohort’s follow-up does not establish performance in other populations or diagnostic workflows.
In practice
For patients with primary cutaneous melanocytic tumors that remain ambiguous on initial pathology, this cohort supports a stepwise specialist assessment: expert histopathologic review followed by molecular analyses when needed. The approach yielded a diagnosis in 97.2% of 994 referred patients, and follow-up outcomes were consistent with the assigned categories. These findings support the diagnostic approach but do not establish that it performs similarly in other settings; the study was conducted at a tertiary referral center in the Netherlands.
AI-generated clinical interpretation · Not editor-reviewed
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Journal of Clinical Oncology: Expert Histopathologic Evaluation and Molecular Analyses for Ambiguous Cutaneous Melanocytic Tumors ↗This is an automated AI-condensed summary that has not yet been reviewed by an editor. Always consult the full item at the original source.