Complications of auricular cartilage harvest in rhinoplasty: Keloid and epidermal cyst formation

Abstract

Keloid scars and epidermoid cysts present unique challenges in plastic surgery, often requiring distinct diagnostic and therapeutic approaches. Keloid scars result from dysregulated wound healing characterized by collagen overproduction and inflammatory states. In contrast, epidermoid cysts are cutaneous lesions lined with keratinized epithelium, with the rare complication of development into squamous cell carcinoma. A rare clinical dilemma is when epidermoid cysts arise within keloidal scar tissue. In this case, effective management involves meticulous diagnostic approaches, including ultrasonography and histopathological examination, to identify coexisting cysts within scar tissue. In the few studies reporting this rare occurrence, various treatment protocols exist consisting of various combinations of surgical excision, intralesional corticosteroid injections, chemotherapeutic agents, laser therapy, radiotherapy, isotretinoin, and tranilast. As advancements in the comprehension and treatment of epidermoid cysts within keloid scars progress, customized therapeutic approaches provide promise for enhancing patient outcomes and quality of life.

Key Words: Rhinoplasty; Surgery; Recurrence; Keloid scar; Epidermoid cyst; Ear

Core Tip: This case report presents a rare co-occurrence of a keloid and epidermal cyst at the site of auricular cartilage harvest for rhinoplasty. Understanding the complexities and having a meticulous and individualized approach to its treatment, surgical intervention, and postoperative care is essential for optimizing surgical outcomes. This case report highlights the importance of a personalized approach, stressing the need to consider potential complications during surgical planning and patient counseling.

INTRODUCTION

Keloid scars and epidermoid cysts are recognized as distinct dermatological entities with unique histological characteristics and clinical behaviors, each requiring different courses of treatment[1,2]. This raises an important question; what should surgeons do when an epidermoid cyst formation occurs within keloidal scar tissue?

The pathophysiological mechanisms for keloid scarring have yet to be fully elucidated, as evidenced by the wide range of therapeutic approaches available[3]. However, the keloid triad hypothesis stands out, as it links a diverse set of etiological factors, including genetics, infective agents, and skin tension, as contributors to keloid scar development[3]. For plastic surgeons, both the surgical approach and post operative wound management are crucial controllable risk factors to consider during surgical planning[3]. According to the keloid triad hypothesis, plastic surgeons must address these risk factors by carefully planning the orientation of incisions and sutures, managing wound tension, preventing healing by secondary intention, and avoiding keloid-prone sites for harvesting when possible[3].

While there is no universally accepted treatment protocol, combination treatment is considered to be the most effective[4]. For small to moderate sized keloids (< 20 cm²), conservative, non-surgical multimodal management is appropriate consisting of intralesional steroid injection, corticosteroid tape/plaster, or intralesional chemotherapeutic agents[5]. Triamcinolone acetonide (5-10 mg) should initially be injected at the keloid's border rather than the hard scar center, such that once the scar has softened, subsequent injections can target the center[5]. Corticosteroid tape/plaster, such as flurandrenolide (4 mcg/cm²) or deprodone propionate can be cut to match the shape of the scar and used continuously for a few months[5]. Low dose intralesional chemotherapeutic agents like fluorouracil (1.5 to 5 mg/mL) or bleomycin (1 mg/mL) can be combined with triamcinolone injections (2 to 10 mg/mL)[5].

Surgical excision with postoperative adjuvant therapy may be selected in patients who prefer surgery due to cosmetic reasons[5]. For larger keloids, surgical excision with postoperative adjuvant therapy is the first line of treatment[5]. Complete or near-total excision of the keloid is preferred over core extirpation, as removing the entire scar tissue reduces the likelihood of recurrence[5]. There are exceptions to this, for example, keloids on the cartilaginous part of the auricle or the digits can be resected with core excision. In addition, specific anatomic sites may require a special surgical technique, such as keloids that form on the earlobe which are removed using wedge excision and primary closure[5].

Excising keloids without further postoperative treatment is associated with recurrence rates between 55%-100%[6]. The use of intralesional triamcinolone injection has been proven effective in reducing keloid recurrence rates to approximately 50% following surgical excision, even contributing to reducing the volume of the scar itself[6]. However, the response to triamcinolone intralesional injection is highly variable[6]. Radiotherapy may also be used following the decision as a means of disrupting aberrant wound-healing processes to prevent keloid formation[6]. Intralesional injection of fluorouracil following injection may also be used to enact an inhibitory effect on fibroblasts and prevent keloid reformation[6]. Pressure therapy using specialized garments and devices can be used in combination with other treatments to reduce the risk of keloid formation by addressing different aspects of scar formation[6]. Applying continuous pressure flattens the keloid, reduces the tension on the skin, and helps in the remodeling of scar tissue and appearance over time[6]. Cryotherapy, pulse dye laser and ablative carbon dioxide (CO₂) lasers have also been described with positive outcomes[6].

Epidermoid cysts have been reported following surgical procedures, as surgical interventions can inadvertently introduce epidermal elements into the deeper dermal layer, leading to the formation of epidermoid cysts[2,7]. Treatment of epidermoid cysts often involves the surgical excision of the cyst. An initial incision and drainage may also be necessary to properly evacuate the cyst[2]. In cases where an epidermoid cyst ruptures, leading to the spread of keratin into surrounding tissues and triggering a reactive inflammatory response, surgical excision may be combined with neoadjuvant intralesional triamcinolone injection[2]. Epidermoid cysts may also be treated with a CO₂ laser or cryotherapy[2]. In cases where keloid scars coexist with epidermoid cysts, the treatment strategy must address the complexities introduced by both conditions[8]. Given that the management of keloid scars and epidermoid cysts differs significantly, surgical excision is often prioritized for epidermoid cysts, whereas keloid scars carry an increased risk of post-excision recurrence. Therefore, tailored treatment approaches are essential to restore optimal aesthetic outcomes[8].

CHALLENGES AND MANAGEMENT STRATEGIES

Typically, the clinical diagnosis of keloid scars is sufficient, and biopsy is often avoided as it is thought to increase the keloid size. Because of this, when keloids and epidermoid cysts occur together, epidermoid cysts are often missed, and the heterogeneous lesion is treated as a keloid scar instead[5]. A prospective study conducted in south China from January 2018 to July 2021 observed 461 patients with keloid scars, among whom 14.92% were identified through ultrasonographic assessment to have co-occurring epidermoid cysts[9]. When epidermoid cysts within keloidal scar tissue are left undetected, patients exhibit poorer response to intralesional corticosteroid treatment (0.05 mL/injection at a concentration of 40 mg/mL every 28 days for a total of 4 sessions) compared to patients with keloid scars without epidermoid cysts[9]. The results from this study highlight the necessity of thorough diagnostic evaluations through ultrasonography to identify co-occurring epidermoid cysts, as their presence significantly impacts treatment effectiveness.

Although the co-occurrence of keloids and epidermoid cysts is rare, a handful of case reports have documented their presence and treatment. Yi et al[10] reported the successful treatment of recurrent earlobe keloids in a 26-year-old patient, which developed due to failed healing from an ear piercing. When the keloid underwent subsequent re-excision, multiple cyst-like lesions were discovered and dissected intraoperatively. Following the discovery of these cysts, they were fully excised, followed by a postoperative treatment regimen of intralesional triamcinolone injection, laser treatment, and isotretinoin (30 mg daily) for three months and minocycline (200 mg daily) for six months[10]. Lee et al[11] performed a retrospective study of six Korean patients with epidermoid cysts arising from scar tissue, predominantly located on the anterior chest wall, shoulder, forehead, and ear lobule. Management strategies varied, including total scar revisions, partial excisions combined with epidermoid cyst removal, and laser therapy, as an alternative treatment for patients preferring less invasive procedures or concerned about cosmetic outcomes[11,12]. Postoperative adjuvant treatment included the application of taping fixation for 1 month and the use of silicone gel sheets for 5 months[11]. In the case of partial keloid scar excision with complete epidermoid cyst excision, triamcinolone injections were administered to the remaining scarred areas to prevent keloid scar formation[11]. No complications were reported, and none of the patients experienced scar recurrence during the follow-up period (mean of 14.8 months)[11]. The authors proposed two mechanisms to explain the co-occurrence of epidermoid cysts and keloid scars, drawing on clinical observations and existing knowledge of the histopathology of these lesions[11]. Firstly, epidermoid cysts may originate from traumatic events, where remnants of inflammatory follicular tissue become trapped within scar tissue[11]. Secondly, in regions subject to shearing forces, epidermal elements can embed themselves within scar tissue, fostering epidermoid cyst formation[11]. This process may also occur in pruritic keloid scars, where excoriation introduces epidermal elements into the scar tissue, potentially contributing to cyst development[11].

Finally, Kim et al[8] present a case of concurrent ear keloid and epidermoid cyst involvement following auricular cartilage harvest for rhinoplasty. The lesions appeared 9 months after the rhinoplasty at the auricular cartilage harvest site, which progressively worsened, leading to her seeking medical advice one year after surgery[8]. During surgical excision, an epidermoid cyst was discovered encapsulated within the keloid tissue[8]. After surgically removing both the keloid and cyst, the area was covered using a fillet flap technique[8]. Post-operative care consisted of the application of a silicone sheet and gel to the scar area, and a prescription of oral tranilast (300 mg/day) for 3 months[8]. These studies highlight the diagnostic and therapeutic challenges of treating epidermoid cysts within keloid scars, reflecting diverse existing practices and the need for further research in evidence-based approaches. While there is existing literature on the rare co-occurrence of keloids and epidermoid cysts, it provides additional support for reasons to consider and prepare for such complications in clinical practice, in patients with predisposing factors. However, the authors did not delve into the patient demographics, specifically ethnicity, pregnancy, and puberty, all of which are concurrent risk factors relating to the development of keloids[3]. The report could also benefit from a discussion on the differential diagnosis and more detailed exploration of the pathophysiological mechanisms behind the coexistence of these lesions. Additionally, detailing the surgical approach for auricular cartilage harvest, especially with regards to instances that may have introduced unnecessary trauma or tension to tissues, could provide insight on iatrogenic causes of the coexistence of keloids and epidermoid cysts. Detailed reporting of surgical approach may aid in the future implementation of techniques that protect against keloid formation, which is of particular interest to plastic surgeons. Key strategies for minimizing complications during auricular cartilage harvest include using an anterior approach to reduce auricular deformity, employing local injections of lidocaine with epinephrine for vasoconstriction and improved visualization, careful dissection of the supraperiosteal plane to identify landmarks and minimize tissue trauma, and handling adjacent skin flaps[13]. Overall, the case report offers valuable insights and could serve as a robust resource for clinicians with further discussion on patient demographics, differential diagnoses, deeper exploration of the underlying mechanisms, and proper surgical technique.

CLINICAL IMPLICATIONS

In plastic surgery, the site of tissue harvest is pivotal, especially in patients prone to aberrant wound healing, such as those with a history of keloid formation[3]. Avoiding harvesting from areas susceptible to increased tension, such as the chest, shoulders, upper back, and earlobes, may prevent complications related to keloid formation at incision sites[3]. Similarly, surgical techniques that increase wound tension should be avoided, such as the use of long, linear closures, midline closures, wound closures across joints, wound edge eversion, and wound lengthening techniques such as Z-plasty[5]. In addition, improper suture techniques including poor wound edge alignment, inadequate support of wound edges, and foreign body reaction, can contribute to keloid scar formation through excessive tension and disruption of natural healing processes[5]. Addressing these factors is essential for optimizing surgical outcomes, thereby enhancing patient satisfaction with aesthetic results and ensuring improved overall satisfaction with the surgical experience.

CONCLUSION

Often overlooked due to overlapping clinical manifestations, the concurrent presence of epidermoid cysts within keloid scar tissue poses a noteworthy clinical challenge within the realm of plastic surgery[14]. Effective management hinges on accurate diagnostic tools such as the use of ultrasonography, followed by tailored therapeutic strategies incorporating surgical excision, intralesional corticosteroid injections, laser therapy, and adjunctive pharmacotherapy[15]. Early recognition and intervention hold promise in minimizing recurrence rates, optimizing aesthetic outcomes, and improving patient prognosis. This represents a paradigm shift in scar management, prompting plastic surgeons to broaden their approach beyond what is visible on the surface to optimize post-operative outcomes in plastic surgery.