Vulval lichen planus: progression of pseudoepitheliomatous hyperplasia to invasive vulval carcinomas

Abstract

A 62 year old woman attended our clinic in 1996 with a 40 year history of dyspareunia and a three month history of a vulval tumour. A histological diagnosis of lichen planus had been made at the age of 40. Despite two introital enlarging procedures, sexual intercourse became impossible by the age of fifty. Cutaneous, occular, auditory, oral and pharyngeal involvement have required medical interventions from many disciplines. Topical and intralesional steroids, isotretinoin and etretinate had all been used without benefit. Examination revealed a raised tumour measuring 2cm in diameter with features suggestive of a keratinising squamous cell carcinoma on the right anterior vulva. There was loss of the labia minora and burying of the clitoris. The severely narrowed introitus showed well defined and marked erythema consistent with lichen planus. The vagina was almost obliterated with adhesions. The histological features of the excised lesion were of pseudoepitheliomatous hyperplasia in an area of lichenoid chronic dermatitis. There was marked epithelial proliferation with irregular expansion and down growth of the epidermis. Nuclei and nucleoli were enlarged, there were few mitoses and hyperchromasia was not identified. Similar histological features were noted in a second vulval tumour which was excised six months later. Two further vulval lesions were treated with intralesional triamcinolone acetonide 10mg/mL without benefit and oral cyclosporin (3mg/kg). This resulted in some improvement in her generalised lichen planus. However, a further vulval tumour measuring 2cm in diameter developed during mid 1999. Histology of the excised specimen revealed a well differentiated squamous cell carcinoma. The severity of the lesion and the degree of atypia were more marked than in the earlier excised specimens. The thickness of the lesion was 4mm and depth of invasion 1mm (Stage 1A vulval carcinoma). There was an associated prominent deep plasma cell infiltrate. The patient re-presented a year later with two adjacent tumours in a new site on the anterior vulva. Histology of both excised tumours again revealed pseudoepitheliomatous hyperplasia. In the larger lesion (2cm × 1.5cm) there was evidence of a further well differentiated squamous cell carcinoma with a depth of invasion of 3mm (Stage 1B). The diagnosis of well differentiated squamous cell carcinoma was based on the more disorderly arrangement of the cells, the deeper extension of the lesion and the degree of nuclear atypia. There was an associated prominent deep plasma cell infiltrate (1, 2). A well differentiated Stage 1B squamous cell carcinoma invades almost to the subcutis. The SCC merges with PSEH in an area of LP. The squamous cell carcinoma merges with the pseudoepitheliomatous hyperplasia in an area of lichen planus. Lichen planus is a relatively common dermatological condition which results in a wide range of mucocutaneous lesions. It is seen less commonly in gynaecological practice where it may present diagnostic difficulties. We describe the clinical course of a woman with longstanding lichen planus who initially was seen with vulval lesions clinically suggestive of squamous cell carcinoma but with histological features of pseudoepitheliomatous hyperplasia. Further lesions developed over the course of the disease and finally there was histological evidence of squamous cell carcinoma arising in the pseudoepitheliomatous hyperplasia. We believe this is the first report of these associations in vulval lichen planus. This case raises two issues. First, the relationship between lichen planus and carcinoma of the vulva; and secondly, the development of pseudoepitheliomatous hyperplasia in chronic vulval lichen planus, and evidence of subsequent pseudoepitheliomatous hyperplasia lesions demonstrating progression to invasive carcinoma. The development of squamous cell carcinoma in oral, penile and hypertrophic lichen planus of the lower legs is well documented. Lichen planus has been noted in a small number of women as an incidental histological finding in the vulval skin adjacent to squamous cell carcinoma of the vulva1,2. There is one report of a woman with longstanding lichen planus developing vulval intraepithelial neoplasia 3 (VIN 3)3 and two of women with known lichen planus developing vulval cancer2,4. While these cases demonstrate an association between lichen planus and subsequent VIN 3 and squamous cell carcinoma of the vulva, there is no evidence of a direct causal effect. This situation may be similar to lichen sclerosus of the vulva where chronic inflammation and epithelial cell hyperplasia may be associated with neoplastic transformation. Pseudoepitheliomatous hyperplasia (also termed pseudocarcinomatous hyperplasia) is a reactive hyperplasia of the epidermis, clinically and histologically suggestive of well differentiated squamous cell carcinoma5. The lack of significant cellular atypia and nuclear hyperchromasia distinguishes this lesion from squamous cell carcinoma. Pseudoepitheliomatous hyperplasia occurs as a response to various stimuli, including trauma, cryotherapy, halogens, chronic irritation and fungal or mycobacterial infections. A detailed history and histological examination excluded these associations in this case and it appears that pseudoepitheliomatous hyperplasia developed as a response to the chronic inflammation associated with longstanding lichen planus. She subsequently developed several new lesions, the most recent being a well differentiated squamous cell carcinoma. The demonstration in this case of “progression” from a state of benign pseudoepitheliomatous hyperplasia to early malignant neoplasms provides more direct evidence of the potential for chronic lichen planus to undergo malignant transformation. Pseudoepitheliomatous hyperplasia is considered to be a benign condition, but evidence from this case indicates that invasive carcinoma can arise in the affected skin. We believe the situation may be similar to that seen in lichen sclerosus. The lesions in this case presented significant diagnostic difficulties for both the clinician and the histopathologist. Women with vulval lichen planus should have regular long term follow up with expert histological examination of suspicious lesions.