Incidental Squamous Cell Carcinoma in an Epidermal Inclusion Cyst: A Case Report and Review of the Literature

Abstract

Epidermal inclusion cysts are common lesions that rarely develop into squamous cell carcinoma (SCC). Neoplastic change in these cysts can be associated with prominent symptoms such as pain, rapid growth, or ulceration. This study describes the case of a 64-year-old woman with a 4-year history of a largely asymptomatic neck mass, which after routine excision was found to be an epidermal inclusion cyst harboring well-differentiated SCC. The diagnosis was made incidentally after routine cyst bisection and hematoxylin and eosin staining. Given the potential for variable presentation and low cost of hematoxylin and eosin analysis, we recommend a low threshold for a comprehensive pathological search for malignancy in excised cysts when appropriate.

Perineal squamous cell carcinoma arising from an epidermal cyst: a case report

“…An epidermal cyst is a benign disease caused by invagination of epidermal elements into subcutaneous fat from a hair follicle [ 5 ]. Although it is a common skin lesion, malignant transformation of an epidermal cyst is very rare [ 1 , 2 ]. The incidence of a malignant change from an epidermal cyst to cutaneous SCC is 0.011–0.045% [ 6 ].…”

“…Epidermal cysts and squamous cell carcinomas (SCCs) are common skin lesions [ 1 ]. However, cutaneous SCC arising from an epidermal cyst is quite rare [ 2 ]. The most common sites are the head and neck, and it has also been reported in the trunk, limb, and gluteal regions [ 3 ].…”

Therapeutic approach to epidermoid cyst

“…Less than 1% of these cysts can undergo malignant transformation either to a squamous cell carcinoma or a basal cell carcinoma. [1][2][3] There is a heredofamilial tendency in a few cases. It is seen in autosomal dominant conditions such as Gardner's syndrome (familial polyposis of the colon) or Gorlin's syndrome (basal cell nevus syndrome).…”

“…Patients on drugs such as BRAF inhibitors, cyclosporine and imiquimod have a high incidence of developing inclusion epidermal cysts. [3][4][5][6] Epidermoid cysts originate from the follicular infundibulum. Plugging of the follicular orifice leads to the formation of a cyst.…”

Squamous cell carcinoma arising from a nasojugal cyst

“…Chronic inflammation, immunosuppression and trauma are recognised risk factors . A history of rapid growth and a failure to medically treat a suspected infected cyst should raise suspicion for malignancy …”