Basal cell carcinoma of the vulva: a case report and systematic review of the literature

The vulva is an unusual site for basal cell carcinoma (BCC). Vulvar BCC accounts for <1% of all BCCs and <5% of all vulvar malignancies. We report the case of an 83 year‐old woman who presented with a 2‐month history of a tender labial growth, with histopathology confirming nodular BCC. We conducted a systematic literature review of the characteristics of reported cases of vulvar BCCs. A comprehensive systematic review of articles indexed for MEDLINE and Embase yielded 96 reports describing 437 patients with 446 BCCs of the vulva. The mean age at presentation was 70 (range 20–100). Most women had no underlying vulvar disease. Approximately 60% of cases were of the nodular subtype. Treatment approach varied widely with over half of cases treated with wide local or local excision. Mohs micrographic surgery (MMS) for vulvar BCC was first reported in 1988 with seven total MMS cases reported. Twenty‐three cases of recurrence have been reported; 21 of these cases after local excision but none following MMS. Vulvar BCC is a rarely reported cancer that affects older women predominantly. MMS represents a promising treatment for BCC in this anatomic location.


Introduction
While basal cell carcinomas (BCC) are the most common human malignancy, the vulva is an unusual location, with vulvar BCCs accounting for <1% of all BCCs. 1 Additionally, BCC of the vulva accounts for <5% of all vulvar malignancies. 2,3 BCC of the vulva most commonly affects elderly women. Presenting symptoms include pruritus, a lump, bleeding, and pain. 4 The proposed risk factors for BCC occurring in non sun-exposed sites such as the vulva include radiation therapy and basal cell nevus syndrome. 5,6 Treatment options for vulvar BCCs include radical and simple vulvectomy, wide local excision, simple surgical (local) excision, and Mohs micrographic surgery (MMS). We report the case of an 83-year-old woman who presented with a BCC of the vulva. We also review the characteristics of the reported cases of vulvar BCCs in the literature, including treatment approach. titles and abstracts for relevance. Two reviewers assessed the remaining articles for inclusion, with disagreements going to a third reviewer. Only published case reports or case series in peer-reviewed journals were included in this review, with publication years ranging from 1950 to 2015. Case series that presented case reports in aggregate form were included even if these reports did not specify lesion details beyond location and histopathology. In most case reports, lesion size, specific anatomic site, patient age, treatment, recurrence, associated metastases, and provider specialty were available. These data were noted and tabulated yielding 96

Results
The mean age at presentation was 70 years (range 20-100). Of the 437 patients, seven patients had more than one vulvar tumor (two of whom had three primary tumors) resulting in a total of 446 cases of vulvar BCC. 5,6,32,38,53,54 Risk factors for the seven patients with multiple BCC of the vulva included four patients with a previous history of multiple BCC on sun-exposed sites, 32,38,53,54 two patients with history of radiation to pelvis, 5,54 and three patients with Gorlin's syndrome. 6,14 Overall, most women did not have underlying vulvar disease; however, in three patients, BCCs arose in contiguity with extramammary Paget disease. 7,44,63 Two BCCs arose within an area of lichen sclerosus 57,59 while in a third case, a BCC arose adjacent to the area affected by lichen sclerosus, 34 as was seen in our patient.

Anatomic site
The exact site on the vulva was documented in 212 cases. The labium majus was the site of origin in 162 cases, the clitoris in 10, labium minus in eight, perineum in four, vagina/surrounding introitus and posterior fourchette in three each, and one BCC arose from the periurethral mucosa. Twenty-one further cases involved more than one anatomic location due to the larger size of tumor at presentation. Potential risk factors in these patients included underlying extramammary Paget disease in two women, 7,44 five patients with aggressive histology such as infiltrative, morpheaform, and infundibulocystic BCC patterns, 7,56,61,71,91 two patients with a history of previous BCC on sun-exposed sites, 71,76 and seven patients with a documented late presentation, with either lesion ulceration, large size, and/or metastases. 36,[60][61][62]71,91 Histopathologic subtype Specific histopathologic subtype of the BCC was documented in 199 cases (Fig. 2) and included 116 (58%) cases that were nodular, 30 (15%) superficial, and 27 (14%) infiltrative. There were 10 documented cases displaying more than one BCC histopathologic subtypesix were nodular, infiltrative, and superficial; three were nodular and superficial; and one was nodular and infiltrative and contiguous with a squamous cell carcinoma (SCC). Other reported histopathologic diagnoses were four cases of mixed BCC and SCC, three total cases of BCC contiguous to SCC (one mentioned above), and 10 cases of

Metastatic BCC
Twelve cases in this series of 446 were metastatic (2.7%).    MMS has been associated with improved cosmetic and functional outcomes. 5,65 MMS may be the best chance of cure, especially with increased tumor size, aggressive histology, and when maximum uninvolved tissue preservation is desired. 20 The use of MMS for treatment of vulvar BCC may lead to improved rates of local recurrence. MMS represents a promising treatment for BCC in this anatomic location; however, further experience with MMS for vulvar BCC is needed to confirm this observation.

Questions (answers found after references)
1 In which decade do most patients experience vulvar BCC?