# Delayed presentation of an iatrogenic postauricular epidermal inclusion cyst after ear surgery: a case report

## TL;DR

A rare case of a skin cyst forming behind the ear two years after ear surgery is reported, highlighting the importance of proper surgical techniques and accurate diagnosis.

## Contribution

This case report presents a rare iatrogenic epidermal inclusion cyst following tympanoplasty, emphasizing diagnostic and surgical considerations.

## Key findings

- A 26-year-old male developed a postauricular cyst two years after ear surgery, confirmed as an epidermal inclusion cyst.
- The cyst was successfully treated with complete surgical excision, with no recurrence or complications.
- The case underscores the need for a broad differential diagnosis and proper surgical closure to prevent epithelial entrapment.

## Abstract

Epidermal inclusion cysts (EICs) are slow-growing, non-malignant lesions typically arising from entrapped epidermal cells within the dermis. While commonly seen in areas such as the face and neck, their occurrence behind the ear is uncommon. In rare instances, EICs may develop after surgery due to the unintended implantation of skin epithelium during the closure process. We describe a 26-year-old male who developed a gradually enlarging mass in the left postauricular area, 2 years following tympanoplasty. The patient reported no associated symptoms or trauma. The physical examination revealed a firm, tender swelling without any skin changes. Imaging indicated a soft tissue lesion with mastoid sclerosis. Initial antibiotic therapy was ineffective. Surgical exploration revealed a cystic structure, which was completely removed. Histological evaluation confirmed an EIC with no malignant features. The patient recovered without complications. This case illustrates a rare postoperative occurrence of an EIC following ear surgery. Given the potential for such lesions to mimic other conditions, clinicians should maintain a broad differential diagnosis. Proper surgical closure technique may help reduce the risk of epithelial cell entrapment. Complete excision remains the definitive treatment for preventing recurrence and ensuring optimal patient outcomes.