Intratendinous Epidermoid Cyst after Traumatic Penetration of Foreign Body: A Very Rare Case Report

Intratendinous epidermal cysts are extremely rare soft-tissue lesions. Apart from traumatic occasions which are usually painful, in asymptomatic cases, they can be easily overlooked. The purpose of our study was to report the formation of an intratendinous epidermoid cyst after traumatic penetration and irritation of a wooden foreign body.

A 79-year-old man proceeded in the emergency department, with a skin cut in the dorsal side of the right hand from a sharp wooden segment. After surgical lavage and investigation for soft-tissue damages or subcutaneous foreign bodies, skin closure was performed. Ten months after trauma, the patient came again with persistent pain and limitation in range of motion of the ring finger. Ultrasonography demonstrated an intratendinous foreign body surrounded by the cystic lesion. Both the identified wooden fragment and the cyst, which were histopathologically verified as an epidermoid cyst, were removed.

Clinicians should be aware that a tendon injury, along with chronic irritation from a foreign body, might result in the formation of an intratendinous epidermoid cyst.