DP12 Practice variation in melanocytic tumours of uncertain malignant potential (MELTUMP): survey data

Abstract

Melanocytic tumours of uncertain malignant potential (MELTUMP) describes melanocytic lesions with atypical but nondefinitive malignant features, leaving biological potential uncertain. Evidence is limited and management varies. We aimed to characterize current clinical practice in Ireland and the UK. An online cross-sectional survey was distributed to dermatologists and plastic surgeons via professional societies. Items addressed investigation triggers, excision margins, sentinel lymph node biopsy (SLNB), follow-up, ancillary testing, multidisciplinary team (MDT) discussion and guideline use. Descriptive statistics were reported; interspecialty comparisons were made using a χ2-test or Fisher’s exact test. Thirty-six clinicians responded (20 dermatology, 15 plastic surgery, 1 general surgery); 89% were consultants. Pathologist opinion was most influential (94%), followed by thickness (56%), ulceration (53%), mitotic activity (50%) and age (47%); 76% considered adolescence the highest risk. Wide local excision was recommended by 97%, with preferred margins of 5 mm (50%) or 10 mm (39%), without specialty difference (P = 0.62). SLNB was generally reserved for melanoma reclassification (67%); 17% would consider it for adverse features (P = 0.47). Follow-up varied: melanoma-equivalent regimens (44%), fixed 5 years (22%) or discharge after wide local excision (17%). Ancillary diagnostics were widely available (86%), most often PRAME (69%) and BAP1 (58%), with no specialty variation (P > 0.99). MDT discussion was universal (92%). Only 11% used guidelines, although 72% felt consensus recommendations would improve care (P = 0.70). This first UK–Ireland survey demonstrates substantial variation in MELTUMP management, particularly regarding margins, SLNB and follow-up, despite near-universal MDT access and ancillary testing. Minimal guideline use contrasts with strong demand for consensus, highlighting the need for clear recommendations to standardize practice.