Vulvar squamous cell carcinoma and lichen sclerosus

There are two clinicopathological types of vulvar squamous cell carcinoma, human papillomavirus (HPV)-positive and HPV-negative, which can be distinguished to some degree on routine histology. Human papillomavirus-positive carcinomas account for one-quarter to one-third of cases, occur in women on average 20 years younger than in HPV-negative, and are associated with multiple lower genital tract neoplasia. Human papillomavirus negative carcinoma is linked to lichen sclerosus. Of all carcinomas, 7-96% show lichen sclerosus in skin adjacent to the carcinoma, the majority being the first presentation of lichen sclerosus, and up to 5% of patients with lichen sclerosus develop carcinoma after long-term follow up. Where lichen sclerosus is associated with malignancy, it is often hyperplastic, may show a subtle form of intraepithelial neoplasia termed 'differentiated vulvar intraepithelial neoplasia', and may lose its pathognomonic oedematous-hyaline layer. The local additional factors causing lichen sclerosus to develop malignancy on the vulva are not known.     

p16INK4a and p14ARF tumor suppressor genes are commonly inactivated in cutaneous squamous cell carcinoma

The p16(INK4a) and p14(ARF) tumor suppressor genes (TSGs) are encoded within the CDKN2A locus on chromosome 9p21 and function as cell cycle regulatory proteins in the p53 and RB pathways. Inactivation of these genes by genetic and epigenetic changes has been described in some human cancers, but their importance in cutaneous squamous cell carcinoma (SCC) has not been established. Our detailed examination of 40 cutaneous SCC revealed loss of heterozygosity of 9p21 markers in 32.5% of cases. Mutational analysis confirmed five point mutations in four of 40 SCCs. These mutations changed the amino acid sequence of p16(INK4a) in four tumors and p14(ARF) in three tumors. Promoter methylation of p16(INK4a) and p14(ARF) was detected in 13 of 36 (36%) and 16 of 38 (42%) cases, respectively. Absent protein expression was confirmed by immunohistochemistry in 13 of 16 (82%) of the tumors with biallelic inactivating events. Overall, the frequency of 9p21 alterations was 76% and for both p16(INK4a) and p14(ARF), promoter methylation is the commonest mechanism of gene inactivation. Alterations at this locus were significantly more common in tumors from immunocompetent compared with immunosuppressed individuals. These data confirm the importance of inactivation of p16(INK4a) and p14(ARF) TSGs in the pathogenesis of cutaneous SCCs.     

Microinvasive squamous cell carcinoma arising on lichen sclerosus of the penis

The case of a 70-year-old white man with a 10-year history of penile lichen sclerosus (LS) who developed microinvasive squamous cell carcinoma on LS is described. A high incidence of penile cancer arising on genital LS has recently been observed. The authors stress the importance of an adequate diagnosis and long-term follow-up in patients with penile LS because of the malignant potential of the disease.     

Spindle and pseudoglandular squamous cell carcinoma arising in lichen sclerosus of the vulva

An 83-year-old woman presented with a vulval mass. Radical vulvectomy was performed and histology showed a unique mixed picture of spindle, pseudoglandular and classical squamous cell carcinoma arising in vulval lichen sclerosus.     

外阴硬化萎缩性苔藓与外阴鳞状细胞癌的基因研究

外阴硬化萎缩性苔藓是较为常见的一种慢性皮肤黏膜病变，部分患者可能发展为外阴鳞状细胞癌。近年来的研究发现，外阴硬化萎缩性苔藓可能与多种癌基因、抑癌基因突变及其表达异常存在着密切联系。综述与外阴硬化萎缩性苔藓和外阴鳞状细胞癌相关的十余种癌基因与抑癌基因，分析从外阴硬化萎缩性苔藓发展到外阴鳞状细胞癌的因素。     

Human papillomavirus-associated squamous cell carcinoma of the nail bed in African-American patients

Background  Human papillomavirus (HPV) has been implicated in the development of digital squamous cell carcinoma (SCC). Case reports in the literature mostly identify HPV type 16 present in tumors, but HPV types 2, 31, 34, 35, and 73 have also been isolated.
Methods  Two cases of digital SCC associated with HPV 16 in young African-American men are presented.
Results and conclusions  Digital SCC associated with HPV may be difficult to evaluate and treat, particularly in African-Americans and patients with human immunodeficiency virus (HIV). We discuss the need for careful evaluation, treatment, and follow-up of these individuals.     

Lichen sclerosus and squamous cell carcinoma

Lichen sclerosus is a chronic inflammatory disease that can progress to malignancy. The literature indicates an association with anogenital squamous cell carcinoma and verrucous carcinoma. Two pathogenic pathways, differentiated vulvar and penile intraepithelial neoplasias, which have recently been described in relation to squamous cell carcinoma, are both highly associated with genital lichen sclerosus independently of human papilloma virus (HPV) infection. Furthermore, tumor-promoting molecular changes unrelated to HPV infection have been demonstrated and may explain the malignant potential of lichen sclerosus. The possible relationship between HPV and genital lichen sclerosus currently remains open to discussion, and the prognostic importance of the overlapping of these 2 diseases is still unclear. This review considers the relationship between lichen sclerosus and squamous cell and verrucous carcinomas, the possible oncogenic mechanisms involved, and their possible association with HPV infection.     

Lymphohistiocytic and granulomatous phlebitis in penile lichen sclerosus

Lichen sclerosus (LS) is a chronic inflammatory disease of unknown etiology that may affect the genital and/or extragenital skin of individuals of either sex at all ages. In boys, the prepuce is the most common site of involvement. The diagnostic criteria of LS include the presence of inflammatory infiltrates mainly composed of T lymphocytes. We report on two cases of LS of the prepuce because of the unusual feature of lymphocytic (CD45RO+ and CD20+), histiocytic (CD68+), and granulomatous phlebitis. This lesion was not present in a group of another 18 cases of childhood penile LS. We have not been able to find any references describing and illustrating inflammatory involvement of the dermal vein walls in LS. Unlike the data reported in the literature, the dermal inflammatory infiltrates of these two cases showed a similar proportion of B and T lymphocytes in addition to frequent CD68+ histiocytes.     

High incidence of lichen sclerosus in patients with squamous cell carcinoma of the penis

BACKGROUND: There is a well-documented association between lichen sclerosus (LS) and vulval carcinoma in women; however, until recently, there have only been anecdotal reports of penile squamous cell carcinoma (SCC) occurring in men with LS. OBJECTIVE: The incidence of penile carcinoma occurring on a background of LS remains uncertain, and we wished to examine this possible association further. METHOD: To address this, all the cases (n = 20) of penile SCC held on our pathology database (4 years) were examined. Histology was reviewed, blind to the clinical picture, for evidence of LS, applying strict histological criteria. Subsequently, clinical notes were reviewed for history of LS before the SCC presented, and history of previous circumcision, treatments, node involvement, metastases and death. RESULTS: In eight cases, evidence of LS was found in the excision specimen. Seven of these had well-differentiated SCC. In the 12 cases with no evidence of LS, only three were well differentiated. With case note review, seven had a history of LS (four with histological LS), sometimes preceding the SCC by 10 years. These all had well-differentiated SCC. Ten of the 20 patients are dead, seven from metastatic disease. Four deaths occurred in the 'well-differentiated LS' group, but only one from penile SCC metastatic disease. CONCLUSIONS: There appears to be a definite association between SCC of the penis and the presence of LS, similar to that reported between LS and vulval SCC in women. Of the 20 patients with penile SCC studied, 11 had a clinical history and/or histological evidence of LS. However, clinical presentation of the LS or need for circumcision may precede the SCC by many years. As follow-up is impractical, counselling at the time of diagnosis is very important, and it is essential that medical practitioners are aware of this association so that the subsequent risk from SCC is reduced.     

Altered p53 expression and epidermal cell proliferation is seen in vulval lichen sclerosus

Aberrant p53 immunoreactivity has been found in skin premalignancies and dysplasias such as Bowen's disease and actinic keratoses. Vulval lichen sclerosus (LS) has been reported to be pre-malignant, with an association of vulval carcinoma in 3% to 6% of patients. In contrast, non-genital LS appears to have no malignant potential. In this immunocytochemical study, we investigated p53 expression in 10 cases of histologically proven vulval LS and 9 cases of non-genital LS using the murine monoclonal antibody Do-1 raised against recombinant human p53 which reacts with both wild-type and mutant p53. None of the vulval specimens had epithelial dysplasia or malignancy. Normal vulval (7 cases) and non-genital skin (5 cases) were used as tissue controls, respectively. The cell proliferation index was also studied using the MIB 1 monoclonal antibody which detects the cell-cycle associated Ki-67 antigen. The technique of microwave irradiation for antigen unmasking was employed on Formalin-fixed and paraffin-embedded tissues. There was a significant increase in p53 immunoreactivity in vulval LS (32.13 ± 15.11 epidermal cells per 100 basal cells) compared to normal vulval skin (7.52 ± 5.04 epidermal cells per 100 basal cells) (p < 0.001), whereas the MIB 1 labelling index was lower in vulval LS (39.45 ± 15.88 epidermal cells per 100 basal cells) than in normal controls (86.26 ± 32.31 epidermal cells per 100 basal cells) (0.001 < p < 0.01). In contrast, there was no significant difference in p53 immunoreactivity or MIB 1 labelling index between non-genital LS and normal controls. Vulval LS, when compared to non-genital LS (8.76 ± 6.61 epidermal cells per 100 basal cells), also demonstrated a significant increase in P53 immunoreactivity (p < 0.001). The reduced proliferative index in vulval LS may be directly related to its increase in p53 expression and is in keeping with the role ol p53 in the negative regulation of cell proliferation. We propose that the difference in p53 expression may represent a difference in biological behavior between vulval LS and non-genital LS. What role it plays in the evolution of vulval carcinoma in a setting of long standing LS is uncertain.     

阴茎鳞状细胞癌1例

报告1例阴茎鳞癌，患者男，50岁，阴茎龟头菜花样肿块3年，破溃1年，3年半前有尖锐湿疣史，皮损组织人乳头瘤病毒（HPV）6，11型阳性，组织病理，高分化鳞癌（龟头皮损），淋巴结慢性炎症和反应性增生（右腹股沟）。     

p16INK4a expression in actinic keratosis and Bowen's disease

BACKGROUND: Progression of cutaneous squamous neoplasms from actinic keratosis (AK) to Bowen's disease (BD; squamous cell carcinoma in situ) has important implications for clinical management and treatment, thus requiring accurate diagnosis. p16INK4a is a cell cycle regulatory tumour suppressor protein that negatively regulates D-type cyclins in the G1 cell cycle phase via intimate interplay with the retinoblastoma gene. Expression of a paraffin-reactive p16INK4a marker has recently been shown to increase in cervical squamous neoplasms as lesions progress from low-grade dysplasia to squamous cell carcinoma in situ. p16INK4a expression in the progression of squamous cutaneous neoplasia, however, has not been evaluated. OBJECTIVES: To evaluate p16INK4a expression in the progression of squamous cutaneous neoplasia. METHODS: Biopsies of 203 squamous cutaneous neoplasms with unequivocal features of AK (n = 87) and BD (n = 116) as well as a benign squamous control group (verruca vulgaris: n = 10; seborrhoeic keratosis: n = 11; scar tissue: n = 8) obtained between January and December 2001 at Henry Ford Hospital (Detroit, MI, U.S.A.) were immunostained for p16INK4a (Dako; clone E6H4; dilution 1 : 50) using large core (1.5 mm) tissue microarray analysis. Nuclear/cytoplasmic immunoreactivity in > 10% of neoplastic cells was considered positive. RESULTS: Of 203 cases, 166 (81.8%) were interpretable (AK 59; BD 107). Mean patient age was 71.0 years (range 33-93); 57% were male. Sites of involvement were: head and extremities 75.9%, trunk/buttocks 21.7%, genital region 2.4%. p16INK4a immunostaining was positive in 90 of 107 (84.1%) BD cases, four of 59 (6.8%) AK cases and none of 29 benign squamous controls. The sensitivity and specificity of p16INK4a for a diagnosis of BD (vs. benign squamous controls/AK) was 84.1% and 95.5%, respectively (P < 0.0001, Fisher's exact test, two-sided). CONCLUSIONS: p16INK4a is a sensitive and specific marker for distinguishing BD from AK/benign squamous cutaneous lesions and may be helpful as an adjunct to histomorphology in the diagnosis and appropriate clinical management of these lesions.     

Human papillomavirus-associated digital squamous cell carcinoma: literature review and report of 21 new cases

OBJECTIVE: Our aim was to review the clinical behavior of human papillomavirus (HPV)-associated digital squamous cell carcinoma (SCC). Specifically, we examined evidence for the tumor's (1) infectious origin and spread, (2) response to therapy, and (3) prognosis and metastatic risk. DESIGN: We reviewed and performed data tabulation of all 51 reported cases in the English-language literature and a case series of 23 cases (21 of them not previously reported). We present 2 of the cases in depth. SETTING: We used previously reported cases from MEDLINE and a case series from a single dermatologic operation practice from 1985 to 1999. RESULTS: (1) Of all cases, 10% (7/72) had an antecedent genital dysplasia or carcinoma containing the same HPV subtype as the digital SCC. (2) The rate of recurrence after general surgical therapy was 43% (6/14). After Mohs micrographic surgery the recurrence rate was 13% (2/16) for the cases in the literature, and 26% (6/23) for our case series. (3) Of tumors, 3% (2/72) have been observed to metastasize. CONCLUSIONS: (1) This suggests the possibility of genital-digital spread as a mechanism of tumor genesis. (2) HPV-associated digital SCC is more likely to recur after surgical treatment than previously reported. This rate of recurrence greatly exceeds that for cutaneous SCCs in general and may be caused by residual postsurgical HPV. (3) The rate of metastasis, however, appears to be low.     

p16INK4a与HPV感染相关疾病

p16是抑制CDK4和6的肿瘤抑制蛋白。高危型HPV中的致癌基因E7可使p16^INK4a失去pRb的反馈性抑制而过度表达且功能异常。低危型HPV感染相关的尖锐湿疣中p16^INK4a免疫活性表现为离散、点状分布的阳性。中高危HPV感染相关的鲍恩样丘疹病中p16^INK4a免疫活性表现为弥漫强阳性。p16^INK4a较HPV型别能更客观地推测尖锐湿疣、鲍恩样丘疹病恶变的可能。