Cutaneous squamous cell carcinoma of the eyelid in northern latitudes, a 25‐year experience in Finland

Purpose To evaluate the incidence, clinical features, diagnostic challenges, management and prognosis of cutaneous squamous cell carcinoma of the eyelid (ecSCC) in southern Finland, northern Europe, latitude 62° N. Methods Patients were identified from the Finnish Cancer Registry and the Helsinki University Hospital databases during a 25‐year period (1998–2022). Age, sex, location, clinical and histopathological diagnosis, treatment and outcome were retrieved. Results Cutaneous squamous cell carcinoma of the eyelid (ecSCC) was diagnosed in 58 patients. The mean age‐standardized incidence was 1.03 per 100 000. Median age at the time of histopathological diagnosis was 79 (range 55–93) years; sex ratio was 0.52. Clinical diagnosis in the referral was ecSCC in only three patients. The most frequent misdiagnosis (38%) was basal cell carcinoma (BCC). One or more of the known risk factors (smoking, history of extensive sun exposure, systemic immunosuppression and previous in situ cSCC/cSCC) were documented in 71% of the patients. More than one third (38%) of the patients developed in situ SCC elsewhere on the skin; one third (31%) of the patients had invasive cSCC elsewhere. During the median follow‐up time of 24 months, three patients experienced local recurrence, four patients developed metastatic disease (median 19 months) and two patients died of metastatic ecSCC. Conclusion The estimated incidence of ecSCC in Finland (predominantly white Caucasian) was higher than in a previous study from Europe. Clinical diagnosis of ecSCC is difficult and often misdiagnosed as BCC. Immunosuppression as a risk factor should noticed. Recurrences of ecSCC, which may be lethal, were infrequent.