Clinical Suspicion Sensitivity of Nodular and Superficial Spreading Melanoma
Trude E. Robsahm, Per Helsing, Henrik L. Svendsen, Marit B. Veierød
In Norway, nodular melanoma is the most fatal melanoma subtype and superficial spreading melanoma the most common, indicating diagnostic challenges. The aim of this study was to assess the clinical suspicion sensitivity of nodular melanoma and superficial spreading melanoma, by diagnosing physician, using randomly selected 100 nodular melanomas and 100 superficial spreading melanomas from the Norwegian Melanoma Registry, diagnosed in 2014 to 2015. Information about suggested diagnoses and diagnosing physician was collected from pathology request forms. Suspicion sensitivity was defined as the proportion (%) of cases with “melanoma” as a suggested diagnosis, estimated with 95% confidence interval (95% CI). Most melanomas (74.5%) were diagnosed by non-dermatologists, with a suspicion sensitivity of 23% (95% CI 15–34) for nodular melanoma and 24% (95% CI 16–35) for superficial spreading melanoma. Corresponding estimates for dermatologists were 50% (95% CI 32–68) and 96% (95% CI 80–99), respectively (pinteraction=0.007). The low suspicion sensitivity for both subtypes among non-dermatologists calls for educational efforts.
In a population-based material of 100 superficial spreading melanoma and 100 nodular melanoma, similarly low clinical suspicion sensitivity was found for nodular melanoma (30%) and superficial spreading melanoma (42%). When separating by diagnosing physician, the suspicion sensitivity among non-dermatologists was found to be less than 25% for both melanoma subtypes, which calls for educational efforts. Among dermatologists, sensitivity for superficial spreading melanoma was high (96%) and lower for nodular melanoma (50%), emphasizing the challenge of recognizing nodular melanoma.