Faltaous Adel A, Leigh Emilia C, Ray Peter, Wolbert Thao T
Department of Surgery, Division of Plastic and Reconstructive Surgery, Marshall University, Huntington, WV, USA.
Am J Case Rep. 2019 Aug 3;20:1141-1143. doi: 10.12659/AJCR.912828.
BACKGROUND Epidermoid cysts are the most common benign skin lesions that can occur anywhere on the body, and frequently occur on the face, scalp, neck, and trunk. Typically, patients are asymptomatic, and the lesions present as firm skin-colored nodules filled with keratinous or sebaceous materials that are formed by cystic expansion of the epidermal epithelium. Malignant transformation is rare in epidermoid cysts. CASE REPORT This is a case report of a 77-year-old male Caucasian patient who presented with an epidermoid cyst on the left parietal area. Due to high suspicion, the cyst was surgically excised and sent to pathology which resulted in discovery of malignant squamous cell carcinoma with unclear margins. Aimed at obtaining clear margins, a wide excision was performed, which revealed clean margins and absence of residual cancerous cells. The patient recovered well without major complications. CONCLUSIONS Although the prevalence of epidermoid cysts is high, malignant transformation of epidermoid cysts into squamous cell carcinoma is rare. Due to its scarcity, the exact pathophysiology of malignant transformation is still poorly understood. The differential diagnosis should include the possibility of malignancy for highly suspicious lesions, and proper management guidelines should be established. Surgical resection should be the treatment of choice, and once removed, all surgically excised cysts should undergo pathologic evaluation. As clinicians, it is crucial to stay vigilant and have a low threshold for excision and thorough histological examination of specimens to allow early diagnosis and interventions which can significantly improve patient outcomes. Through the suggested guidelines, we hope to aid in better management and intervention in case of malignant transformation of epidermoid cysts.
表皮样囊肿是最常见的良性皮肤病变，可发生于身体任何部位，常见于面部、头皮、颈部和躯干。通常，患者无症状，病变表现为坚实的肤色结节，充满由表皮上皮细胞囊性扩张形成的角质或皮脂物质。表皮样囊肿恶变罕见。
本文报告一例77岁白人男性患者，其左顶叶区域出现一个表皮样囊肿。由于高度怀疑，该囊肿被手术切除并送病理检查，结果发现为恶性鳞状细胞癌，切缘不清晰。为获得清晰切缘，进行了广泛切除，切缘清晰且无残留癌细胞。患者恢复良好，无重大并发症。
尽管表皮样囊肿的患病率很高，但表皮样囊肿恶变为鳞状细胞癌的情况罕见。由于其罕见性，恶变的确切病理生理机制仍了解甚少。对于高度可疑的病变，鉴别诊断应包括恶性的可能性，并应制定适当的管理指南。手术切除应作为首选治疗方法，所有手术切除的囊肿均应进行病理评估。作为临床医生，保持警惕并对切除标本进行全面组织学检查的阈值较低至关重要，以便早期诊断和干预，这可显著改善患者预后。通过建议的指南，我们希望有助于更好地管理和干预表皮样囊肿恶变的情况。
