Epidermoid cysts localized on extremities.

Objectives: This study aims to investigate the incidence, anatomic localization, relationship to trauma, treatment complications, relapse ratios after treatment, and factors affecting relapse of epidermoid cysts localized on the extremities.

Patients and methods: The study evaluated retrospectively 120 patients (76 males, 44 females; mean age 41.8 years; range 9 to 76 years) diagnosed with and operated due to epidermoid cyst localized on the extremities between January 2012 and June 2017. Patients' age, gender, cyst's localization, anatomic localization, complaint duration, and trauma history were investigated as well as whether a cutaneous islet was left on the cyst and whether any cyst rupture occurred intraoperatively; and relapse and association of relapse ratios with these parameters.

Results: There was no statistically significant difference between patients with or without relapse in terms of age, gender distribution, or cyst size or localization (p>0.05). Relapse ratios were significantly lower in patients in whom a cutaneous islet was left intraoperatively (p<0.05). Relapse ratios were significantly higher in patients who developed intraoperative cyst rupture (p<0.05). There was no significant relationship between relapse and trauma history (p>0.05). Intraoperative cyst rupture ratios were significantly lower in patients in whom a cutaneous islet was left intraoperatively (p<0.05).

Conclusion: Epidermoid cysts are most frequently localized on the hands. They may also be atypically localized with different dimensions and characteristics. Well definition of the cyst margins and characteristics and avoiding intraoperative rupture while excising the cyst together with the cutaneous islet are essential to reduce possible postoperative complications and relapse ratios.