To evaluate the incidence, clinical features, diagnostic challenges, patient and healthcare-related delays, management, and outcomes of lacrimal sac squamous cell carcinoma (lsSCC) at a tertiary care centre.

We identified patients from the Finnish Cancer Registry and the Helsinki University Hospital (HUS, Helsinki, Finland) databases over a 16-year period 2007–2022 and analysed clinical features, histopathology, human papillomavirus (HPV) positivity by immunohistochemical staining for p16INK4A (p16) and mRNA detection by in situ hybridization for high-risk HPV (HR-HPV), and treatment.

The median age at diagnosis for the 13 patients was 67 years (range, 40–97). Median time to histopathologic diagnosis of lsSCC was 6 months (range, 0–36). The most common reason for delay was treatment based on an incorrect diagnosis of dacryocystitis. Eye-sparing surgery was performed in eight (62%) and exenteration in five (38%) patients. Differentiation was classified as grade 2 in 38% and grade 3 in 62% of tumours. Eight of 12 analysed tumours (67%) were HPV positive. The reconstruction method involved a microvascular flap in 54% and a local pedicular skin or fascia flap in 46% of patients. Ten patients received postoperative external beam radiotherapy, and one patient received chemotherapy. The median follow-up time was 5 years (range, 0–17). The patient with regional micrometastasis developed systemic metastatic disease at 11 months and died of metastatic lsSCC 22 months after surgery.

Two-thirds of the patients had an HR-HPV-positive tumour. Diagnosis of lsSCC is often delayed. Despite high tumour grade, recurrences and metastasis of lsSCC were rare in this cohort.