Early vulvar lichen sclerosus: a histopathological challenge

Vulvar lichen sclerosus (LS), a lymphocyte-mediated chronic skin disease, begins with uncharacteristic symptoms and progresses undiagnosed to atrophy and destructive scarring. Some patients with longstanding advanced LS have an increased risk of vulvar carcinoma. Early LS is treatable, although not curable, if diagnosed early. Therefore, patients with persistent vulvar symptoms should be biopsied to establish the diagnosis. In contrast to advanced LS, the histological features in early LS are quite subtle and often more prominent in adnexal structures than in interfollicular skin. Adnexal structures show acanthosis, luminal hyperkeratosis and hypergranulosis with/without dystrophic hair and basement membrane thickening. The epidermis/mucosa shows mild irregular, occasionally psoriasiform acanthosis and focal basement membrane thickening. Early dermal changes are homogenized collagen and wide ectatic capillaries in dermal papillae immediately beneath the basement membrane. The lymphocytic infiltrate can be sparse or dense, lichenoid or interstitial with epidermal lymphocyte exocytosis and lymphocytic/lymphohistiocytic vasculitis. Dermal melanophages indicate preceding keratinocyte/melanocyte destruction. Biopsy specimens of early LS rarely display all features. Therefore, serial sections and periodic acid-Schiff reactions are necessary for their identification. Recognition and treatment of these early stages of LS may result in longstanding remission. Progression to atrophic stages with their associated morbidity and even to squamous cell carcinoma may be prevented.     

Histopathological work-up and interpretation of sentinel lymph nodes removed for vulvar squamous cell carcinoma

Aims:  To evaluate the work-up of sentinel lymph nodes (SLNs) removed for vulvar pT1–pT2 squamous cell carcinoma (SCC). Inguinal lymphadenectomy yields metastases in only 30% of cases. Patients with missed inguinal disease, however, have a risk of dying from systemic disease. SLN dissections reduce morbidity, but work-up should reliably identify metastatic disease.
Methods and results:  All SLNs removed from 38 patients with pT1–pT2 SCC and clinically negative inguinal lymph nodes were submitted for frozen section analysis. When negative, SLN were formalin-fixed, sectioned entirely at 330-μm intervals to produce three slides per millimetre [two haematoxylin and eosin (H&E) stained slides; one slide for immunohistochemistry]. If screening of H&E-stained sections was negative, all remaining slides were subjected to immunohistochemistry with an antibody to cytokeratin. Twenty-five of 38 patients (66%) were pN0, 7/38 (18%) had metastases on frozen sections/H&E stains. Immunohistochemistry detected micrometastases in two patients and single tumour cells and anucleate cell structures in four patients. In 12/13 patients the SLN metastases, including all single-cell deposits, were from lichen sclerosus (LS)-associated SCC. Twelve of 13 patients with metastases had a pT2 SCC.
Conclusions:  Micrometastases and single tumour cell deposits in SLNs are typical of LS-associated vulvar SCC. Single tumour cell deposits in SNLs should be regarded as 'positive'. Identification requires serial sectioning and immunohistochemical analysis of all removed SLNs.     

Review of precancerous vulvar lesions

Classification of squamous vulvar precancerous lesions is based on the concept of vulvar intraepithelial neoplasia (VIN) and incorporates a three grade evaluation of the intensity of dysplastic changes (VIN I, II and III). On the basis of histological features, VIN has been subdivided into the usual VIN (u-VIN) and differentiated VIN (d-VIN), which represent the two basic pathways of the pathogenesis of vulvar squamous cell carcinoma. Although u-VIN is etiologically associated with the human papillomavirus (HPV) infection and histologically corresponds to cervical intraepithelial neoplasia, d-VIN represents the HPV-negative sequence of vulvar carcinogenesis, which is linked to lichen sclerosus (LS) and lichen simplex chronicus (LSC). u-VIN preferentially occurs in relatively young women with a history of cervical, vaginal or vulvar premalignant lesions. On the other hand, d-VIN usually affects postmenopausal women without anamnestic data of other dysplastic lesions of the lower female genital tract. d-VIN is characterized by a higher tendency of stromal invasion than u-VIN and its malignant potential is analogous to carcinoma in situ (VIN III). The histological appearance of d-VIN is subtle with basal atypia and a well-preserved differentiation of the superficial parts of the squamous epithelium, therefore it is frequently misdiagnosed for u-VIN I, LS or LSC in vulvar biopsies. Primarily because of the low diagnostic reproducibility of the u-VIN I category and the doubts about its precancerous potential as well as due to the questionable differentiation between u-VIN II and III, a revised VIN classification was proposed in 2004. The grading of vulvar precancerous lesions was abandoned, the u-VIN I category was discontinued and u-VIN II and III were merged. In the revised terminology, the term u-VIN represents HPV-associated high grade precancerous vulvar lesions (formerly u-VIN II and III) and d-VIN encompasses HPV-negative high grade dysplasias. Keywords: vulvar intraepithelial neoplasia - VIN of the usual type - VIN of the differentiated type - lichen sclerosus - lichen simplex chronicus - HPV.     

Specific intraepithelial localization of mast cells in differentiated vulvar intraepithelial neoplasia and its possible contribution to vulvar squamous cell carcinoma development

van de Nieuwenhof H P, Hebeda K M, Bulten J, Otte‐Holler I, Massuger L F A G, de Hullu J A & van Kempen L C L T
(2010) Histopathology 57, 351–362
Specific intraepithelial localization of mast cells in differentiated vulvar intraepithelial neoplasia and its possible contribution to vulvar squamous cell carcinoma development Aims: The aetiology of vulvar squamous cell carcinomas (SCC) that are not causally associated with high‐risk human papillomavirus remains largely elusive. The aim of this study was to analyse the inflammatory response in its presumed precursor lesions, lichen sclerosus (LS) and differentiated vulvar intraepithelial neoplasia (dVIN), and provide evidence that dVIN is a likely precursor of vulvar SCC. Methods and results: Immunohistochemical analyses for CD4+, CD8+, CD20+, CD68+, S100+ and tryptase‐positive immune cells were performed and quantified in LS (n = 7), dVIN (n = 19), SCC (n = 11), and normal vulvar tissue (n = 8). The subepithelial inflammatory response in dVIN and SCC was comparable, but absent in LS. Abundant intraepithelial mast cells were observed in dVIN only, and confirmed by electron microscopy, toluidine blue staining and cKIT expression. Adjacent keratinocytes displayed increased proliferation as determined by MIB‐1 positivity. Electron microscopy revealed intraepithelial mast cell degranulation. Intraepithelial mast cells were not or infrequently observed in vulvar hyperplasia (n = 13), condylomata acuminata (n = 5), keratinocytic intraepidermal neoplasia of sun‐exposed skin (n = 15), epidermal hyperplasia of head and neck (n = 12), and psoriasis (n = 3). Conclusions: These data indicate that dVIN can be recognized by intraepithelial mast cells and that they might promote the progression of dVIN to SCC.     

Monoclonal gamma-T-cell receptor rearrangement in vulvar lichen sclerosus and squamous cell carcinomas

Risk factors for vulvar squamous cell carcinoma (SCC) are human papilloma virus (HPV) infections and lichen sclerosus (LS). The significance of monoclonal gamma-T-cell receptor (gamma-TCR) rearrangement in the lymphoid infiltrate of LS and the consequence for vulvar carcinogenesis is unknown. One hundred sixty-one biopsies of vulvar LS and SCC, with and without LS, were examined for monoclonal gamma-TCR rearrangement and HPV16 expression, and for the expression of B- and T-cell markers and fascin. Monoclonal gamma-TCR rearrangement was identified in 8 of 17 patients with LS and 11 of 21 patients with SCC arising in LS with only occasional HPV16 DNA detection. None of the 19 SCC without LS showed monoclonal gamma-TCR rearrangement, but 14 of 19 patients had strong HPV16 detection. The lichenoid infiltrate of LS with germline configuration consisted predominantly of T cells (CD8 > CD4), along with numerous B cells. However, in biopsies with monoclonally rearranged gamma-TCR, CD4-positive T cells dominated along with B cells and fascin-positive cells in the lichenoid infiltrate and in deeply located lymphocyte aggregates (LAs). These LAs additionally contained fascin-positive dendritic cells with only individual CD8, CD57, and granzyme-positive cells. LAs in biopsies with germline configuration demonstrated numerous T cells (CD8 >CD4), but only single peripheral B cells, CD57, and fascin-positive lymphocytes. Our data suggest that monoclonal gamma-TCR rearrangement is characteristic for and limited to LS and SCC arising in LS, raising the question for a LS-associated antigen. We interpret B cells, CD4-positive T cells, and fascin-expressing dendritic cells within LS as a cellular immune response to antigen or proliferating T-cell clones. The resulting local immune dysregulation in LS may provide a permissive environment for the development of a SCC.     

Alterations in the expression of two epidermal differentiation antigens in human epidermal disorders

The expression of an epidermal keratin subunit and a specific antigen of the keratinocyte membrane, two differentiation antigens in normal human epidermis, was studied in benign and malignant epidermal lesions by use of monoclonal antibodies KL1 (anti 55-57 Kd keratins) and KL3 (anti keratinocyte membrane antigen). In normal human epidermis, KL1 labelled all keratinocytes from the suprabasal layers, KL3 stained the intercellular spaces in all epidermal layers with a fluorescence intensity increasing from the basal to the more upper layers and recognized a keratinocyte membrane antigen as demonstrated in electron microscopy. Frozen or deparaffinized sections of basal cell carcinomas (BCC), squamous cell carcinomas (SCC) malignant melanomas, warts, and skin biopsies from benign lesions (psoriasis, lichen planus, bullous pemphigoid, lupus erythematodes, pemphigus, vasculitis) were tested with either KL1 or KL3 by indirect immunofluorescence and/or immunoperoxidase. Benign and malignant lesions in which modifications of the keratinization process and cell differentiation are known to occur (BCC, SCC, warts, psoriasis) showed the most severe alterations as compared to normal epidermis. With KL1 we observed an irregular staining of basal cells; a reorganization of keratin filaments and variable staining intensities within tumoral cells which did not express high MW keratins. With KL3 drastic alterations in the epidermal intercellular patterns and loss of reactivity of tumoral cells were noted. Conversely, the positivity of epidermal basal cells with KL1, in some cases, was the only modification noted in other skin lesions.     

Vasculitis in lichen sclerosus: an under recognized feature?

AIMS: To analyse 90 vulvar and 72 penile cases of lichen sclerosus (LS) on haematoxylin and eosin sections for vascular changes and the vascular infiltrates immunohistochemically with antibodies to T cells, B cells and antigen-presenting dendritic cells. LS is a skin disease of presumed autoimmune origin. Autoimmune diseases are mediated by lymphocytes which occasionally produce a lymphocytic vasculitis. METHODS AND RESULTS: Three types of lymphocytic infiltrates were identified: (i) perivascular lymphocytic infiltrates without damage to vessel walls; (ii) lymphocytic vasculitis in three forms: (a) concentric lymphohistiocytic infiltrates with lamination of the adventitia by basement membrane material which was typical for penile LS; (b) lymphocytic vasculitis with dense perivascular lymphocytic cuffing with occasional fibrin deposition in vessel walls and subendothelial lymphocyte infiltration, quite common in vulvar LS; and (c) intramural lymphocytic infiltrates in large muscular vessels; (iii) leukocytoclastic vasculitis in LS was exceptionally rare. In lymphocytic vasculitis, CD20+ B cells, CD4+ T cells and dendritic cells were the principal infiltrating cells. CONCLUSIONS: Dendritic cells capture (foreign) antigens after entry into the affected tissues and initiate immune responses acting as a matrix on which antigen-specific T and B cells interact. The described vascular features are indicative of antigen-mediated vasculitic changes in LS.     

Markers for dysplasia of the upper aerodigestive tract. Suprabasal expression of PCNA, p53, and CK19 in alcohol-fixed, embedded tissue.

Recognition of premalignant lesions in the oral epithelium has the potential to increase survival rates for squamous cell carcinoma of the oral cavity. It has previously been reported that cytokeratin 19 (CK19), a 40-kd epithelial cytoskeletal protein within the suprabasal squamous epithelium, is a specific marker of moderate-to-severe dysplasia and carcinoma in situ in oral cavity squamous epithelium. In contrast, normal epithelium and hyperplastic lesions reportedly express CK19 only in the basal layer if at all. The authors chose to test and extend this hypothesis by studying suprabasal CK19 expression and dysplasia of the oral cavity and upper aerodigestive tract in paraffin-embedded specimens that had been fixed in alcohol, a superior fixative for the preservation of cytokeratins. The authors examined 56 alcohol-fixed, paraffin-embedded specimens including 37 from the oral cavity, using two antibodies specific for CK19 (Ks19.1 and 4.62), an antibody to the nuclear proliferation marker, proliferating cell nuclear antigen (PCNA) (19A2), and an antibody to the putative tumor suppressor gene, p53 (pAb1801). The lesions were classified as normal, hyperplasia, mild dysplasia, moderate dysplasia, severe dysplasia/carcinoma in situ, or invasive squamous cell carcinoma, following standard histologic criteria. Immunocytochemically stained sections were scored for the presence or absence of suprabasal CK19, suprabasal PCNA, and p53 positivity, regardless of location. The immunostaining patterns of the two anti-CK19 antibodies were essentially equivalent. Except for one laryngeal specimen, normal epithelium, when positive, showed CK19 expression only in scattered cells throughout the basal layer. Proliferating cell nuclear antigen-positive nuclei were found exclusively in the basal layer. In areas of hyperplasia, CK19 immunostaining was absent or confined to the basal layer in 20 of 38 specimens and was expressed in suprabasal cells in 18 of 38 hyperplastic specimens. Proliferating cell nuclear antigen immunostaining in all cases of hyperplasia was limited to the basal layer. Severe dysplasia and carcinoma in situ showed suprabasal CK19 staining in six of nine specimens and no CK19 staining in three of nine specimens. In contrast, suprabasal PCNA immunostaining was found in all dysplasia and carcinoma in situ cases. p53 expression was detected in three of nine severe dysplasia/CIS specimens and was immunocytochemically undetectable in all normal, hyperplasia, and mild to moderate dysplasia specimens. The authors conclude that suprabasal CK19 expression is neither a sensitive nor a specific marker of premalignancy in oral epithelium and cannot be used to distinguish hyperplasia from dysplasia. In contrast, a strong correlation between suprabasal expression of PCNA, a marker for proliferating cells, and dysplasia/carcinoma in situ was evident.(ABSTRACT TRUNCATED AT 400 WORDS)     

In the absence of (early) invasive carcinoma, vulvar intraepithelial neoplasia associated with lichen sclerosus is mainly of undifferentiated type: new insights in histology and aetiology

BACKGROUND: Differentiated vulvar intraepithelial neoplasia (VIN) is presumed to be the precursor of invasive squamous cell carcinoma (SCC) of the vulva. It is commonly assumed that differentiated VIN is related to lichen sclerosus (LS). However, evidence for this is limited to a small number of studies describing epithelial alterations adjacent to vulvar SCC. AIM: To study the histology and human papillomavirus (HPV) status in patients with a history of both LS and VIN without coexistent SCC. METHODS: Original biopsy specimens and surgical specimens of patients retrieved from the pathology files were revised for the presence of LS, VIN and (early) invasive SCC, specifically focused on the two different types of VIN: differentiated and undifferentiated. Thereafter, VIN lesions were tested for the presence of HPV DNA. RESULTS: Twenty-seven patients fulfilled the criteria for LS and VIN without SCC. In all 27 patients, LS was found to be related to undifferentiated VIN. Grading yielded the following results: VIN 1 (n=10), VIN 2 (n=11) and VIN 3 (n=6). Additionally, VIN lesions from 26 patients could be tested for the presence of HPV DNA. HPV DNA, predominantly type 16, was present in 8 (31%) of them. Seven of these eight patients had VIN 2 or 3. During follow-up, three patients progressed to (early) invasive carcinoma. In two of these patients, differentiated VIN was observed overlying early invasive SCC. CONCLUSIONS: VIN related to LS without coexisting SCC is likely to be undifferentiated, in contrast to what was previously thought. HPV DNA was demonstrated in 31% of the lesions, and was strongly related to high-grade VIN.     

Suprabasal p53 immunoexpression is strongly associated with high grade dysplasia and risk for malignant transformation in potentially malignant oral lesions from Northern Ireland

AIMS: No good predictive marker for the malignant transformation of potentially malignant oral lesions (PMOLs) is currently available. This study re-evaluated the value of p53 immunoexpression to predict malignant transformation of PMOLs after discounting possible confounding factors. METHODS: PMOLs from 18 patients who showed progression to carcinoma, 16 of the respective carcinomas, and PMOLs from 18 matched controls were evaluated by immunohistochemistry (IHC) for p53 expression. A mouse monoclonal antibody that detects wild-type and mutant forms of human p53 was used. The p53 immunostaining pattern was also correlated with the degree of dysplasia. RESULTS: Suprabasal p53 staining was significantly associated with high grades of dysplasia (p < 0.01). The specificity and positive predictive value (PPV) for malignant transformation of suprabasal p53 staining were superior to the assessment of dysplasia, but sensitivity was inferior. All carcinomas derived from PMOLs with suprabasal p53 showed strong p53 immunostaining. However, the absence of suprabasal p53 staining and/or dysplastic changes did not preclude malignant transformation in a considerable proportion of PMOLs. CONCLUSIONS: This study confirms and extends previous findings that suprabasal p53 immunoexpression has a high PPV for malignant transformation of PMOLs and can be used as a specific marker for lesions that are at high risk for malignant transformation. The absence of suprabasal p53 staining (that is, absence of, or basal, p53 staining) is non-informative for prognostic purposes. Because of its limited sensitivity, p53 IHC is not a substitute for the assessment of dysplasia in the evaluation of PMOLs. Instead, p53 IHC emerges as a clinically useful supplement of histopathological assessment in the prognosis of PMOLs.     

Immunohistochemical expression of Mdm2 and p53 in penile verrucous carcinoma

Verrucous carcinoma (VC) of the penis is an uncommon squamous tumor that pursues a biologically indolent course. Unlike conventional squamous cell carcinoma (SCC) of the penis, pathogenic roles for human papillomavirus (HPV) infection and p53 mutation have not been reported in VC. We compared the immunohistochemical expression of Mdm2 and p53 in 7 cases of VC and 7 cases of SCC. The Mdm2 gene product preferentially labeled the perinuclear membrane in the granular layer of VC tumor cells, whereas SCC cases showed weak, focal, cytoplasmic staining for Mdm2. The mean labeling index for Mdm2 was higher in VC compared to SCC [79.3 (SE +/- 7.2) in VC vs 18.3 (SE +/- 2.4) in SCC, p < 0.001]. In SCC cases, the normal surrounding skin showed mild granular-layer staining and dysplastic foci that failed to stain with Mdm2 antibody. Weak p53 immunolabeling was seen within nuclei of scattered tumor cells in the cases of VC, whereas the SCC cases showed strong nuclear staining of p53 throughout the tumors. The mean labeling index for p53 was lower in VC compared to SCC [24.8 (SE +/- 3.9) in VC vs 64.7 (SE +/- 9.0) in SCC, p < 0.01]. In SCC cases, the normal surrounding skin showed moderate staining for p53, preferentially confined to the basal layer. Dysplastic foci in the cases of SCC showed increased p53 labeling. In summary, immunohistochemical analysis showed significantly different levels of expression of Mdm2 and p53 in penile VC vs SCC. Overexpression of the Mdm2 gene product may be important in the pathogenesis of VC. Since Mdm2 is a negative regulator of p53, overexpression of Mdm2 may explain why p53 is down-regulated and, therefore, permissive to oncogenic transformation.     

Immunohistochemical expression of Bax and Bcl-2 in penile carcinoma

There is a complex interplay between the pro-apoptotic Bax and anti-apoptotic Bcl-2 family of proteins and the tumor suppressor gene p53. The pathogenic role of Bax and Bcl-2 protein expression in penile carcinomas has not previously been investigated. We examined Bax and Bcl-2 expression in verrucous (VC) and squamous cell carcinoma (SCC) of the penis. Herein we also present a concise review of p53, Bcl-2/Bax ratios, and their relationship to apoptosis. Fourteen cases of penile carcinoma, including 7 VC and 7 well-differentiated SCC, were analyzed for Bax and Bcl-2 expression by immunohistochemical analysis of paraffin embedded archived tissues. The number of positively staining tumor cells was enumerated per 100 tumor cells within non-overlapping high power fields. The Bax immunoreactivity was similar in VC (19+/-3%) and well-differentiated SCC (15+/-4%) (p = 0.69). The expression of Bcl-2 protein was significantly higher in well-differentiated SCC (69+/-12%) compared to VC (36+/-14%) (p = 0.04). The mean Bcl-2/Bax ratio was significantly lower in VC (1.89) compared to well-differentiated SCC (4.6) (p = 0.05). These findings indicate that penile VC and SCC are immunophenotypically distinct. Bax expression is comparable in verrucous and low-grade squamous cell carcinomas, but Bcl-2 expression of Bcl-2 is significantly higher in the squamous cell carcinomas.     

Langerhans cells in vulvar lichen sclerosus and vulvar squamous cell carcinoma

Introduction: Langerhans cells (LCs), specializing in antigen presentation, are a very important part of the skin immune system (SIS). Materials and Methods: Skin biopsies from 22 women with vulvar lichen sclerosus (LS): 15 patients with early and 7 with the late stage of the disease, were evaluated. Five women with vulvar squamous cell carcinoma (SCC) were also examined. The control group consisted of 9 women who underwent plastic surgery of the vulvar region. Immunohistochemical staining was performed on formalin-fixed paraffin-embedded tissues samples using antihuman CD1a antibody (NCL-CD1a-235, Novocastra). Results: Increased numbers of LC stainings were present in early LS, whereas decreased numbers of these cells were present in late LS and in SCC compared with the control group. Conclusions: This study showed that dysregulation of the SIS may lead to suppression of LCs in the vulvar epithelium and may be one of the reasons for a higher tendency for carcinogenesis in the vulvar region.     

Differentiated dysplasia is a frequent precursor or associated lesion in invasive squamous cell carcinoma of the oral cavity and pharynx

The source of precursor lesions of squamous cell carcinoma (SCC) of the oral cavity and pharynx, their classification, and grading are controversial. In contrast, vulvar and penile cancer precursor lesions are known to be related to human papillomavirus or chronic inflammation and can be described using the vulvar intraepithelial neoplasia (VIN) classification system (VIN 1–3) or as differentiated vulvar intraepithelial neoplasia (dVIN), respectively. Oral and pharyngeal SCC precursor lesions are more etiologically diverse, and the spectrum of lesions may thus be wider. No international consensus exists regarding the histological types of precursor lesions or the significance of individual types. We therefore reviewed resection specimens and preceding biopsies of 155 patients with SCC of the oral cavity and pharynx (excluding tonsils) and identified five basic patterns of SCC-associated or precursor lesions: (1) pleomorphic (22/155), (2) basaloid (5/155), (3) differentiated (63/155), (4) mixed (42/155), and (5) verrucous (12/155). Keratinization was a common but variable feature in differentiated, mixed, and verrucous dysplasia. In 11/155 patients, no precursor lesion could be identified. Progression of isolated differentiated dysplasia (ranging from months to years) was documented in 13/155 (8 %) of patients. Our data suggest that full-thickness epithelial dysplasia of pleomorphic or basaloid type is present in <20 % of oral and pharyngeal SCC, and differentiated dysplasia is a frequent precursor or associated in situ lesion. Failure to recognize differentiated dysplasia results in the underdiagnosis of many patients at risk for invasive carcinoma. These results indicate a need to refine criteria to distinguish differentiated dysplasia from morphologically related lichenoid lesions.     

p53 immunoexpression in non-malignant oral mucosa adjacent to oral squamous cell carcinoma: potential consequences for clinical management

p53 is a tumour suppressor gene encoding a protein whose function is impaired in a very large proportion of human cancers. The objectives of this study were to determine the natural history of p53 alterations during stages of oral carcinogenesis, by comparing p53 immunoexpression in oral squamous cell carcinomas (OSCCs), their non-malignant adjacent mucosa, and respective metastases; and to define the potential practical consequences for clinical management of p53 staining in the non-malignant adjacent mucosa. Forty-two samples of non-malignant mucosa adjacent to OSCCs, the respective carcinomas, and six lymph node metastases derived from six of the OSCCs were investigated for p53 protein expression by immunohistochemistry. Seven out of 42 (17%) non-malignant mucosal samples immediately adjacent to OSCC showed suprabasal p53 staining and this was significantly associated with moderate/severe dysplasia (p=0.02). In six of these cases (86%), the respective carcinoma showed p53 immunoexpression in more than 50% of the neoplastic cells and in the remaining case, p53 immunoexpression was found in more than 25% of the neoplastic cells. In all p53-negative carcinomas that showed p53 immunoexpression in the non-malignant adjacent mucosa, p53 staining was never detected above the basal cell layer. Lymph node metastases showed the same patterns of p53 immunoexpression as the carcinomas from which they were derived. When suprabasal p53 staining is present in non-malignant mucosa immediately adjacent to OSCCs, this suggests stable p53 alterations which are maintained upon progression to overt malignancy. The immunostaining in non-malignant mucosa of the resection margins of OSCCs might be a valuable predictor for local recurrences and may therefore have implications for the management of patients who have received surgical treatment for OSCC.     

Molecular pathology and clinicopathologic features of penile tumors: with special reference to analyses of p21 and p53 expression and unusual histologic features.

OBJECTIVES: To examine the histologic features of p21 in penile tumors and to determine the role of p21 and p53 in the pathogenesis of this group of tumors. METHODS: The clinicopathologic features of 87 patients with penile tumors were studied. The expression of p53 and p21 proteins in 49 cases was investigated by immunohistochemistry. RESULTS: Of the 87 tumors studied, 84 represented primary penile tumors (72 malignant and 12 benign) and 3 represented secondary tumors (2 from bladder, 1 from nasopharynx). The primary malignant penile tumors included 66 surface carcinomas with squamous differentiation (92%), 3 cases of Paget disease (4%), 1 case of Bowen disease (1%), and 2 penile urethral squamous cell carcinomas (3%). The former group was subdivided into squamous cell carcinoma (n = 50), verrucous carcinoma (n = 8), basaloid squamous cell carcinoma (n = 3), adenoid squamous cell carcinoma (n = 3), spindle cell carcinoma (n = 1), and adenosquamous carcinoma (n = 1). The benign tumors were squamous cell papillomas (n = 10) and fibromatoses (n = 2). Expression of p21 and p53 was noted in 40% and 89%, respectively, of the 47 patients with primary surface penile carcinoma with squamous differentiation. Positive p21 and p53 expression was also seen in 2 cases of Paget disease. Staining for p21 was often weak and was found in the suprabasal region of carcinomas with squamous differentiation, while p53 expression was seen in the basal region of squamous cell carcinomas. Preinvasive lesions also showed p21 and p53 expression. An inverse correlation between p53 and p21 expression (p53(+)/p21(-) or p53(-)/p21(+)) was noted in half of the squamous cell carcinomas, 4 of 5 verrucous carcinomas, 2 of 3 basaloid squamous cell carcinomas, and in 1 spindle cell carcinoma. The other cases did not show this correlation. CONCLUSIONS: Penile tumors had different histologic variants and p21/p53 expression patterns. Expression of p21 did play a role in some tumors and could be dependent or independent of p53 expression.     

Analysis of clonality and HPV infection in benign, hyperplastic, premalignant, and malignant lesions of the vulvar mucosa

To elucidate the pathogenesis of vulvar carcinomas, we studied clonality and human papillomavirus (HPV) infection in vulvar epithelial diseases. Monoclonal composition was demonstrated in all 9 invasive tumors (squamous cell carcinoma [SCC], 6; basal cell carcinoma, 1; malignant melanoma, 2), 15 of 20 cases of vulvar intraepithelial neoplasia (VIN), 7 of 9 cases of Paget disease, 2 of 6 cases of lichen sclerosus (LS), and 2 of 3 cases of squamous cell hyperplasia (SCH); high-risk type HPV was revealed in 5 of 6 SCCs and 17 of 20 VINs. These observations might imply that a subset of cases of LS and SCH result from a neoplastic proliferation, similar to VINs but not related to infection with high-risk type HPV. In 1 case of SCC with concurrent VIN 3 in an adjacent lesion, both lesions showed the same pattern of X chromosome inactivation and the presence of HPV-16 in episomal and integrated forms, suggesting that monoclonal expansion triggered by high-risk type HPV integration is an early event for carcinogenesis of HPV-associated SCC.