An Examination of Melanoma Detection and Characteristics at a Nova Scotia Tertiary Care Centre, From 2015-2019

Background: Melanoma is one of the most common cancers in Canada,¹ with the highest incidence in Nova Scotia (NS).

Objectives: To describe the demographics, lesion characteristics, and diagnostic accuracy of suspected melanomas excised at the largest center in NS.

Methods: The dermatopathology database was interrogated for cases of possible melanoma from 2015 through 2019. Age, gender, site of lesion, pathologic diagnosis, Breslow depth, and equivocal pathology were assessed.

Results: 984 lesions had a clinical diagnosis of possible melanoma, identifying 301 melanomas. Of these, 142 (47%) were melanoma in situ (MIS) which in females occurred mostly on the extremities, while in males the head predominated. For invasive melanoma (IM), the extremities remained predominant for women, while the back was most common in men. Lower extremity lesions were more likely to be invasive and female patients were more likely to present with them at a younger age compared to males. The pathology was challenging for 23.94% of MIS, and 16.18% of IM. A mean of 3.1 lesions were excised for every melanoma identified.

Conclusions: Early diagnosis of melanoma is challenging clinically and pathologically. Our melanoma detection rate was 31%, with an increasing trend in the proportion of MIS, and decreasing trend in the proportion of IM over the years. Almost 50% of melanomas were detected in early stages, supporting positive outcomes. Melanomas were more common on extremities in females and the back in males. Melanomas on the lower limbs were more likely to be invasive regardless of gender.