The decision only arises when a mole has changed or looks suspicious — leaving an ordinary stable mole alone is the right call for almost everyone, and removing every mole would be wholesale overtreatment. Once a mole is flagged, removing it rarely causes regret, but it is not free. A systematic review of 46 studies (4,201 lesions) found that surgical excision recurs in about 2% of cases and shave excision in roughly 11%, with cosmetic-satisfaction scores for surgical excision the lowest of any technique at 6.2 out of 10 — a real minority unhappy with the scar (Guo & Wang, 2026). And most suspicious moles turn out to be harmless: even consultant dermatologists excise about six benign lesions for every melanoma they find, a figure that climbs toward twenty in primary care (Sidhu et al., 2012). For most people who act, the excision will, in hindsight, have been unnecessary — the price paid for diagnostic certainty.
The watching-and-waiting side carries a heavier but rarer regret. Among people whose mole turned out to be melanoma, 27% had delayed presenting for more than three months, and 44% — the single most common barrier — had simply not realised the change was serious (O’Shea et al., 2017). A qualitative study found the mechanism plainly: changing moles are “often perceived as trivial,” patients delay to avoid “wasting the doctor’s time,” and three of four people later diagnosed with melanoma in that sample never sought help at all — their GP noticed the lesion opportunistically (Walter et al., 2010). The inaction harm is conditional: most who wait are fine, but for the minority whose mole is malignant, delay shifts the stage at diagnosis and can be fatal.
That conditionality is the whole story, and it is why these two numbers must not be read as a clean head-to-head. The action-side proxy is a cosmetic-and-recurrence rate across all excised nevi; the inaction-side proxy is a delay rate measured only among confirmed melanoma patients. They come from different populations, and the inaction figure overstates the risk for any single benign mole while understating the severity for the rare malignant one. What survives the mismatch is a direction consistent with Gilovich and Medvec’s temporal asymmetry: when a mole has genuinely changed, the people who watched and waited are more likely to look back with regret than the people who had it checked and removed — even though, for most individual moles, waiting turns out to have been harmless. The magnitude depends entirely on the base rate of malignancy in the specific lesion, which only a clinician can judge.