Verrucous squamous cell carcinoma of vulva simulating multiple epidermal inclusion cysts.

Sir,

A 42-year-old woman without any significant past medical history was referred to our dermatology department due to her 15-year history of vulvar pruritic lesions. These lesions had reportedly increased in both number and size in the last few months. Vulvar examination revealed numerous skin-colored cystic nodules with hard consistency over both major labia and the clitoris, with signs of severe lichenification as a result of scratching [Figure 1]. There were no palpable inguinal lymph nodes.

Figure 1

Numerous skin-colored cystic nodules resembling epidermal cyst in the major labia and the clitoris

Clinically, the lesions were suggestive of epidermal inclusion cysts, but the location and the high numbers of lesions were unusual for inclusion cysts. The differential diagnosis of vulvar lesions includes a wide range of conditions. We limited our differential diagnoses to cystic lesions known to occur in the vulvar region, i.e., epidermoid cyst, milia cyst, follicular cyst, steatocystoma, trichilemmal cyst, and eccrine hidrocystoma.[1]

To arrive at the correct diagnosis, excisional biopsy of the main lesion was done. The histopathological examination revealed nonspecific epidermal changes with an underlying chronic inflammatory response. We decided to do a partial vulvectomy of the right labia. Histopathological study of the resected specimen revealed multiple cystic structures in the dermis. Microscopic examination under high magnification revealed epithelial proliferation, with dysplasia, presence of mitosis, and areas of infiltration [Figure 2]. On the basis of these findings, it was reported as well-differentiated but infiltrative squamous cell carcinoma (verrucous variant), which affected the surgical margins.

Figure 2

Epithelial proliferation, with dysplasia, presence of mitosis, and infiltrated areas (hematoxylin–eosin stain; 100×)

The patient was immediately referred to the gynecology department where a complete vulvectomy and clitoridectomy with wide security margins were performed. The diagnosis of multicentric verrucous epidermoid carcinoma of vulva was confirmed. Sentinel node were preformed and there were not lymphatic spread of the tumor. In addition, computerized tomography were normal. Ultimately, the case was classified as stage IB (T1N0M0) according to the International Federation of Gynecology and Obstetric staging system.[2] The patient is being followed up in the gynecology and dermatology outpatient departments and has so far shown no signs of recurrence or new lesions.

Carcinoma of the vulva represents between 5-8% of all gynecologic cancers.[2] Among the squamous cell carcinoma affecting the vulva, the verrucous variant is extremely infrequent. As seen in this patient, the lesion is characterized by its slow growth, low rate of metastasis, and high risk of local recurrences.[3] Clinically, it usually presents as a warty or cauliflower-like growth.[4] However, in our patient, the clinical presentation was as epidermal cysts, which made diagnosis difficult.

Histologically, verrucous squamous cell carcinoma shows an exophytic and endophytic growth pattern, with acanthosis and islands of well-differentiated squamous epithelium. Generally, there are areas of deep infiltration of the tumor accompanied by a marked keratinization in the superficial layers.[4] Our patient presented with a multicenter squamous cell carcinoma (both major labia and clitoris were affected), with malignant changes only where the cystic lesions were located. Multicentric and synchronous vulval squamous cell carcinoma has been described earlier[5] although, as far as we know, the verrucous variant occurring in this manner has not been reported to date.

With this case report we wish to stress the importance of viewing with suspicion any benign lesion with an atypical presentation. We strongly recommend histological study in any long-standing lesion with an uncertain diagnosis.