1302 Should All Excised Suspected Epidermoid and Pilar Cysts Undergo Histological Analysis?

Aim

Within our department, there is variation as to whether excised suspected epidermoid and pilar cysts (both often referred to as sebaceous cysts) are sent for histology. This study aimed to assess the clinical risk of not routinely sending these lesions for histological examination.

Method

A retrospective review was undertaken of consecutive patients undergoing excision biopsy of suspected epidermoid/pilar cysts between September 2016 and August 2021. Data recorded included pre-operative suspected diagnosis, operative diagnosis, histology results and whether these results had been reviewed by the surgical team.

Results

202 patients underwent excision of suspected cysts from a single District General Hospital. 112 were pre-operatively diagnosed by Registrars and 85 by consultants. In 177 cases a sample was sent for histology (88%). In 113 of these cases, the result was reviewed by the surgical team (64%).

The concordance between pre-operative diagnosis and histology was 73.8%. Concordance in pre-operative diagnosis with histology results was similar between Registrars and Consultants (80% vs 73.8%, p = 0.007).

The concordance between the operative diagnosis and histology was 82.1%. Of the 36 cases misdiagnosed at operation, histology revealed malignancy in one case (basal cell carcinoma) and pre-malignancy in another (keratoacanthoma).

Conclusions

In our study, there is a high concordance between operative diagnosis and histology (82.1%) with a relatively low risk of missing malignant or premalignant lesions (2/177, 1.1%). Given the potential economic savings, it may be possible for the surgeon to safely select which cysts need histological review rather than routinely sending all specimens.