Ki-67 and p16 Immunostaining Differentiates Pagetoid Bowen Disease From "Microclonal" Seborrheic Keratosis.

OBJECTIVES: We observed keratoses with "clonal" nests present as numerous tiny collections, in which cells in "pagetoid" array are found, a configuration we termed microclonal seborrheic keratosis (MSK). To better distinguish MSK from pagetoid Bowen disease (PBD), we investigated use of immunohistochemical staining. METHODS: Biopsy specimens of 26 MSKs, 17 PBDs, and 11 borderline cases were reviewed for histopathology and stained with p53, Ki-67, and p16. RESULTS: High expression of Ki-67 and p16 was observed in 12 (80%) of 15 PBDs and in one (4%) of 23 MSKs. Low expression of p16 and high expression of Ki-67 were observed in 16 (70%) of 23 MSKs and in two (13%) of 15 PBDs. Expression of p16 was elevated in 12 (80%) of 15 PBDs and in three (13%) of 23 MSKs (P < .0001). CONCLUSIONS: We describe a "microclonal" variant of seborrheic keratosis with morphology sometimes challenging to distinguish from PBD. High expression of p16 and Ki-67 or p16 alone favors the diagnosis of PBD over MSK.

Clonal Seborrheic Keratosis Versus Pagetoid Bowen Disease: Histopathology and Role of Adjunctive Markers.

Clonal seborrheic keratosis (CSK) and pagetoid Bowen disease (squamous cell carcinoma in situ) (PBD) share similar histological features making it sometimes difficult to differentiate the 2. The study group included 29 and 13 cases of CSK and PBD, respectively. Both groups were examined histopathologically (suprabasal mitotic figures, broad rete ridges, crowding of nuclei, nuclear pleomorphism, necrotic keratinocytes, parakeratosis, and dermal inflammation) and immunohistochemically (CK10, Ki-67, and p16). P values for all parameters were calculated using Fisher exact test, 2 tailed. Significant differences were seen regarding mitosis, crowding, nuclear pleomorphism (more common in PBD), and broad rete ridges (more common in CSK). Significant differences were also noted with Ki-67, CK10, and p16 antibodies. Increased Ki-67-positive cells and the presence of >75% positive p16 cells were commonly seen in PBD, whereas CK10-negative cells were a common finding in CSK. A spectrum of staining patterns was observed with CK10 and p16. There is no single reliable criterion to distinguish CSK from PBD. A panel of markers comprising CK10, Ki-67, and p16 seems to be useful in the context of relevant histology.

Human Papillomavirus Infection and p16 Expression in Extragenital/Extraungual Bowen Disease in Immunocompromised Patients.

An increased rate of second nonmelanoma skin cancers is found in immunocompromised patients. Epidemiological and molecular data implicate ultraviolet radiation as the major risk factor. In addition, there is increasing evidence supporting the role of human papillomavirus (HPV) in the pathogenesis of premalignant and malignant skin lesions in both immunocompetent and immunocompromised patients. In a retrospective cross-sectional study, the authors examined the expression of p16 by immunohistochemistry and the presence of mucosal (α-genus) and cutaneous/epidermodysplasia verruciformis (ß-genus) HPV DNA by polymerase chain reaction in 29 biopsy specimens of extragenital/extraungual Bowen disease (BD) from 24 Eastern European white immunocompromised patients. Furthermore, the author evaluated the association between the expression of p16 protein and the presence of HPV DNA. Among 25 specimens from 21 patients evaluable by polymerase chain reaction, HPV DNA was detected in 10 (40%) BD lesions from 9 patients. Beta-HPV predominated over alpha-HPV types. Among 29 immunohistochemically evaluable BD specimens, 22 lesions (∼76%) from 20 patients were scored as p16 positive. HPV DNA-positive and HPV DNA-negative lesions displayed the same proportion of p16 positivity (80%) and no correlation was found between the HPV DNA presence and the p16 expression status. Our pilot study demonstrated that ß-HPV infections predominate in BD cases diagnosed among immunocompromised patients, although high- and low-risk mucosal (alpha) HPV genotypes may be detected in a minority of cases. In contrast to anogenital HPV-associated lesions, positive p16 expression is not a reliable marker of high-risk α-HPV infection in BD cases, as it can be also detected in ß-HPV infected and HPV-negative cases.

HIPK2 expression in progression of cutaneous epithelial neoplasm.

BACKGROUND: Homeodomain-interacting protein kinase 2 (HIPK2) is responsible for a DNA damage response, centrally regulating p53. The aberrant HIPK2 expression is known to be involved in carcinogenesis in several malignancies. However, the correlation of HIPK2 expression along with progression of cutaneous epithelial neoplasm has not been investigated. METHODS: Using immunohistochemistry and real-time reverse transcription-polymerase chain reaction, we examined the correlation between HIPK2 and HIPK2-related protein expressions and the progression of some cutaneous epithelial neoplasms (i.e., actinic keratosis, Bowen's disease, keratoacanthoma, squamous cell carcinoma, and basal cell carcinoma). RESULTS: HIPK2 expression was distinct between preinvasive and invasive lesions: the expression decreased in keratoacanthoma (none of eight) and squamous cell carcinoma (five of 35) compared to actinic keratosis (12 of 19) and Bowen's disease (10 of 23) (P < 0.001). HIPK2 expression was also negatively correlated with aggressiveness of basal cell carcinoma; high-risk subtypes showed lower HIPK2 expression than did low-risk subtypes (P < 0.001). HIPK2 mRNA expression of each tumor group was significantly higher than that of normal skin. HIPK2 mRNA expression of each tumor group was not correlated with the relevant HIPK2 protein expression, which was consistent with previous studies. CONCLUSIONS: HIPK2 expression tends to be decreased along tumor progression and may be involved with the invasive potential, suggesting a possible tumor suppressor role for HIPK2.

Ultrastructural Examination of a Case of Pagetoid Bowen Disease Exhibiting Immunohistochemical Features in Common With Extramammary Paget Disease.

A panel of immunohistochemical markers may be used to differentiate between pagetoid Bowen disease (PBD) and primary extramammary Paget disease (EMPD) in selected cases. Although diffuse staining with cytokeratin 7 (CK7), CAM5.2, carcinoembryonic antigen, epithelial membrane antigen (EMA), and gross cystic disease fluid protein 15 generally supports diagnosis of EMPD, cases have been reported where PBD also expressed CK7, EMA, and CAM5.2. Based on these findings, some authors suggested that the 2 entities may arise from the same multipotent stem cell, capable of further differentiation toward squamous and secretory lines. To the best of our knowledge, this issue has never been investigated by comparing PBD and EMPD at the ultrastructural level. We performed the first ultrastructural study of a case of PBD exhibiting common immunohistochemical features with EMPD. The lesion displayed some ultrastructural features often observed in Bowen disease and some that are typically found in EMPD. These findings indicate the presence of a bidirectional differentiation--secretory and squamous--within the same lesion, thus supporting the hypothesis that PBD and primary EMPD may arise from a common progenitor cell.

Co-existence of extramammary Paget's disease and Bowen's disease of vulva.

Extramammary Paget's disease and Bowen's disease are histologically similar and immunohistochemistry is often required to make the diagnosis. We present a case of vulval Paget's disease with Bowen's disease in an elderly female. Strong positivity for cytokeratin 7, anti CAM 5.2, carcinoembryonic antigen (CEA) and periodic acid-Schiff (PAS) stain in clitoral, left labial and interface regions of the vulvectomy specimen confirmed the diagnosis of Paget's disease (PD) while positive staining for p63 in the right labial and interface regions helped in establishing the diagnosis of concurrent Bowen's disease (BD).

Expression of p16 protein in lesional and perilesional condyloma acuminata and bowenoid papulosis: clinical significance and diagnostic implications.

BACKGROUND: The histopathological and clinical overlapping features between condyloma acuminata and bowenoid papulosis can present a diagnostic challenge and we sought to determine if immunochemistry can be helpful in this setting. OBJECTIVE: In this study, we evaluate the specificity and sensitivity of p16 immunohistochemistry in condyloma and bowenoid papulosis lesions compared with uninvolved perilesional skin and discuss the possible clinical implications. METHODS: A total of 36 skin biopsy specimens (24 samples of condyloma and 12 samples of bowenoid papulosis with adjacent uninvolved perilesional skin) were stained with an antibody to p16 protein. RESULTS: In all, 75% of condyloma lesions showed sporadic and focal positive staining for p16 protein. All cases of bowenoid papulosis showed diffuse positive staining with p16 protein. Normal-appearing adjacent skin was negative in all cases. LIMITATIONS: Studies with a larger number of cases are needed to confirm our data. CONCLUSION: This immunostain has high sensitivity and specificity for the detection of bowenoid papulosis. Although p16 is expressed in both conditions, the staining pattern in bowenoid papulosis is strongly and diffusely positive involving the full thickness of the epidermis compared with the mostly focal or sporadic pattern observed in condyloma.

Tricholemmoma and clear cell squamous cell carcinoma (associated with Bowen's disease): immunohistochemical profile in comparison to normal hair follicles.

There have been only a few reported comparative immunohistochemical studies of normal hair follicles and tricholemmomas. Clear cell squamous cell carcinomas (SCCs), which are derived from Bowen's disease, histopathologically mimic or are difficult to distinguish from tricholemmal carcinoma. The purpose of and methods used in the present study are as follows: (1) evaluation of whether the immunohistochemical profile (cytokeratin (CK)1, CK10, CK17, CD34, and D2-40) in normal hair follicles is retained in tricholemmomas (11 lesions); and (2) a study of the immunohistochemical profile of in situ or superficially invasive clear cell SCCs (associated with Bowen's disease) (10 lesions) to investigate the presence or absence of tricholemmal differentiation markers in these lesions. The present study demonstrated that (1) the immunohistochemical profile of the normal outer root sheath cells was generally retained in tricholemmomas; (2) in contrast to the D2-40 expression in tricholemmomas (only a peripheral pattern, which is similar to that in the normal outer root sheath), the CD34 expression in tricholemmomas represented in a diffuse pattern, a peripheral pattern, and a combined diffuse and peripheral pattern; (3) tricholemmomas are benign neoplasms with outer root sheath (below the isthmus) differentiation, which characteristically show upregulation of CD34 expression with some functionally similar conditions to the terminal hair follicles in the anagen phase; and (4) there is no clear immunohistochemical evidence of tricholemmal differentiation in clear cell SCC (associated with Bowen's disease).

Pigmented lesion in the inguinal region.

Pigmented Bowen disease (PBD) is a rare tumor characterized by increased melanin pigment in the epidermis or papillary dermis in addition to the typical findings of Bowen disease. We report the case of a 60-year-old woman who presented with a 6-month history of a gradually enlarging solitary dark brown plaque in her right inguinal region. Histopathology showed hyperkeratosis with parakeratosis, acanthosis, disorganization of epidermal architecture, atypical keratinocytes, and increased melanin pigment of the papillary dermis. Considering the clinical and the histological evidence, a diagnosis of PBD was established. Complete resection confirmed the diagnosis. Pigmented Bowen disease is an unusual form of squamous carcinoma in situ. Other tumors in the differential diagnosis include pigmented basal cell carcinoma and superficial spreading melanoma.

Combined analysis of cell growth and apoptosis-regulating proteins in HPVs associated anogenital tumors.

BACKGROUND: The clinical course of human papillomavirus (HPV) associated with Bowenoid papulosis and condyloma acuminatum of anogenital tumors are still unknown. Here we evaluated molecules that are relevant to cellular proliferation and regulation of apoptosis in HPV associated anogenital tumors. METHODS: We investigated the levels of telomerase activity, and inhibitor of apoptosis proteins (IAPs) family (c-IAP1, c-IAP2, XIAP) and c-Myc mRNA expression levels in 20 specimens of Bowenoid papulosis and 36 specimens of condyloma acuminatum in anogenital areas. Overall, phosphorylated (p-) AKT, p-ribosomal protein S6 (S6) and p-4E-binding protein 1 (4EBP1) expression levels were examined by immunohistochemistry in anogenital tumors both with and without positive telomerase activity. RESULTS: Positive telomerase activity was detected in 41.7% of Bowenoid papulosis and 27.3% of condyloma acuminatum compared to normal skin (p < 0.001). In contrast, the expression levels of Bowenoid papulosis indicated that c-IAP1, c-IAP2 and XIAP mRNA were significantly upregulated compared to those in both condyloma acuminatum samples (p < 0.001, p < 0.001, p = 0.022, respectively) and normal skin (p < 0.001, p = 0.002, p = 0.034, respectively). Overall, 30% of Bowenoid papulosis with high risk HPV strongly promoted IAPs family and c-Myc but condyloma acuminatum did not significantly activate those genes. Immunohistochemically, p-Akt and p-S6 expressions were associated with positive telomerase activity but not with p-4EBP1 expression. CONCLUSION: Combined analysis of the IAPs family, c-Myc mRNA expression, telomerase activity levels and p-Akt/p-S6 expressions may provide clinically relevant molecular markers in HPV associated anogenital tumors.

Combined Bowen disease and extramammary Paget disease.

BACKGROUND: The histological resemblance between extramammary Paget disease and Bowen disease has been described since Bowen's original article was published in 1912. METHODS: We herein describe a case of vulval primary extramammary Paget disease in a 61-year-old women with the histological features of Bowen disease. RESULTS: Histological examination of a biopsy specimen showed acanthosis with full-thickness cellular atypia, focal hyperkeratosis and parakeratosis in the epidermis, and no characteristic Paget cells were observed. However, histological examination of an operative specimen revealed areas characteristic of Paget disease and Bowen disease. Overall, the areas characteristic of Bowen disease and Paget disease occupied 6% and 32% of the total operative specimen, respectively. The two areas were sharply separated. Immunohistochemical findings showed carcinoembryonic antigen to be expressed in areas containing Paget cells, but not in the areas characteristic of Bowen disease. Cytokeratin 7 (CK7) (OV-TL 12/30) and CK8 (35betaH11) were strongly expressed in both of these areas. The staining for high-molecular-weight cytokeratins was negative in both of these areas. CONCLUSIONS: Our findings indicated that primary extramammary Paget disease and squamous cell carcinoma in situ arose multifocally from a common cell in the epidermis.

Nature of inflammatory infiltrate in superficial cutaneous malignancies during topical imiquimod treatment.

Topical imiquimod (IQ) is an effective treatment for genital warts and various malignant tumors of the skin. IQ acts through the Toll-like receptor 7 leading to the production of cytokines and chemokines such as interferons, interleukins, and growth factors. We investigated the composition of the inflammatory cell infiltrate before, during, and after the treatment of 10 superficial cutaneous malignancies (melanoma in situ (n = 4), melanoma metastasis (n = 1), squamous cell carcinoma in situ (n = 4), and basal cell carcinoma (n = 1) with 5% IQ cream. Immunophenotyping revealed in all cases during treatment an increased population of T-lymphocytes positive for CD3, CD4 and CD8, as well as a considerable number of cytotoxic cells (TIA-1+, granzyme B+) and plasmacytoid dendritic cells (CD 123+). These findings further support previous investigations that the antitumor effects of IQ result from an enhanced cytotoxic T-cell mediated immune response and from the recruitment of plasmacytoid dendritic cells to the skin. The population of infiltrative inflammatory cells was similar in all patients irrespective of the type of tumor.

Expression of cytokeratin subtypes in intraepidermal malignancies: a guide for differentiation.

BACKGROUND: Among intraepidermal malignancies of epithelial origin, Bowen's disease, bowenoid actinic keratosis (BAK), intraepidermal malignant eccrine poroma (MEP), and Paget's disease may pose diagnostic difficulties. METHODS: Histologic features and immunohistochemical profiles of 24 cases of Bowen's disease, 21 cases of BAK, 18 cases of intraepidermal MEP, and 11 cases of Paget's disease were analyzed. RESULTS: Using multivariate logistic regression test, multinuclear giant cells and solar degeneration were found to be the only histologic parameters of diagnostic help. On the other hand, a widespread positive reaction for CK 5/8, CK 7, CK 19, and negative reaction for CK 10, was a helpful feature in the differentiation of Paget's disease from Bowen's disease and BAK. The widespread and strong expression of CK 10 was seen in almost all cases of Bowen's disease in contrast to BAK. The widespread expression of CK 5/8 and CK 7, and negative reaction for CK 10, was in favor of Paget's disease, compared to intraepidermal MEP. On the other hand, widespread expression of CK 19 was a common finding in intraepidermal MEP, in contrast to Bowen's disease. CONCLUSION: An immunohistochemical panel may provide significant hints on the differentiation of common intraepidermal malignancies, especially in problematic cases.