Notch signaling and the developing skin epidermis.

The innermost (basal) layer of the skin epidermis consists of proliferative progenitors which give rise to multiple differentiating layers providing a barrier that keeps the inside of the body moist and protects the body from outside assaults by physical, environmental and biological factors. The epidermis is maintained throughout life through the proliferation of stem cells and differentiation of their progeny. Notch signaling pathway is a highly conserved molecular network that plays an essential role in cell fate determination during embryogenesis and also in postnatal life. Data from ongoing studies indicate that Notch signaling orchestrates the process of epidermal differentiation and proliferation through the sequential activity of different Notch ligands, receptors and downstream pathways.

Prognostic significance of the alterations of the G1-S checkpoint in localized leiomyosarcoma of the peripheral soft tissue.

BACKGROUND: The aim of this study was to investigate the expression of cell cycle regulators p53, p16, cyclin-D1, and retinoblastoma (Rb) gene protein in leiomyosarcoma of the peripheral soft in order to identify expression profiles potentially useful for clinical prognostic purposes. MATERIALS AND METHODS: A tissue microarray representing 70 localized leiomyosarcomas of the limbs and limb girdles was created with 3 representative cores from each tumor. Immunohistochemical staining was performed for p53, p16, cyclin-D1, and Rb using standard techniques. Staining was scored as either absent-low (<20% of neoplastic cells) or moderate-diffuse (≥20%). Outcome analysis was performed for local recurrence-free survival (LFS), metastatic disease-free survival (MDFS), and disease-specific survival (DSS). RESULTS: Kaplan-Meier analysis of survival revealed that no single alteration of the factors examined was associated with outcome, but tumors showing concomitant alteration of p16 and p53 were characterized by reduced MDFS and DSS (P = 0.01 and P < 0.001, respectively). In addition, patients who received adjuvant therapy consisting of radiotherapy alone or radiotherapy and chemotherapy had a better DSS than those receiving surgery alone or surgery and chemotherapy (P = 0.05). In multivariate analysis, altered p16/p53 remained the only parameter predictive of MDFS and DSS (P = 0.048, hazard ratio [HR] = 2.488, 95% confidence interval [95% CI] 1.006-5.116; P = 0.043, HR = 2.498, 95% CI 1.029-5.909, respectively). CONCLUSIONS: Accumulation of cell cycle alterations represents a prognostic indicator in localized soft tissue leiomyosarcoma, and in particular altered p16/p53 expression is associated with an unfavorable prognosis. This may help the clinical management of patients with leiomyosarcomas.

Application of a filtration- and isolation-by-size technique for the detection of circulating tumor cells in cutaneous melanoma.

Analysis of circulating tumor cells (CTC) in the peripheral blood of cutaneous melanoma patients provides information on the metastatic process and potentially improves patient management. The isolation by size of epithelial tumor cells (ISET) is a direct method for CTC identification in which tumor cells are collected by filtration as a result of their large size. So far, ISET has been applied only to CTC detection from epithelial cancer patients, and the technique has never been applied to cutaneous melanoma patients. We herein investigated the presence of CTC by ISET in the peripheral blood of 140 subjects (87 with cutaneous melanomas, 10 subjects undergoing surgery for melanocytic nevi, 5 patients with non-melanoma skin tumors, and 38 healthy volunteers). The identification of the cells trapped in filters as CTC was supported by positivity for immunohistochemical markers and for tyrosinase mRNA by real-time RT-PCR. CTC were neither detected in the controls nor in the in situ melanoma group. In contrast, CTC were shown in 29% of patients with primary invasive melanoma and in 62.5% of metastatic melanoma patients (P<0.01). CTC detection correlated with the presence of mRNA tyrosinase in blood samples, assayed by real-time RT-PCR (P=0.001). CTC detection corroborated by suitable molecular characterization may assist in the identification and monitoring of more appropriate therapies in melanoma patients.

Primary cutaneous leiomyosarcoma: clinicopathological analysis of 36 cases.

AIMS: Cutaneous leiomyosarcomas (LMS) are rare in comparison with their deep-seated soft tissue and uterine counterparts, and have been poorly characterized. The aim was to verify whether the clinical behaviour of purely dermal LMS is different from that of LMS with minimal subcutis invasion. METHODS AND RESULTS: Twenty-one purely dermal LMS and 15 dermal LMS with minimal subcutis extension were analysed. Tumours developed in 27 men and nine women (age range 29-91 years); most tumours showed a fasciculated (n = 23), pilar-type (n = 12) and pleomorphic (n = 1) pattern. During the follow-up period (range 2-192, mean 41 months) recurrences occurred in 1/16 (6.2%) of tumours confined to the dermis and in 2/11 (18.1%) tumours with minimal subcutis extension. The three recurrent tumours were high-grade LMS, two of which exhibited myxoid areas. One patient with a pleomorphic dermal LMS with minimal extension into fat developed distant metastases 15 years after diagnosis. CONCLUSIONS: For LMS involving the skin, it is advisable to recognize and indicate in the histopathology report the depth of dermal and/or subcutaneous extension, since even minimal subcutaneous involvement may be associated with late local recurrences and/or distant metastases, and therefore appropriate and long-term follow-up is needed.

Primary capillary hemangioblastoma of bone: report of a case arising in the sacrum.

Capillary hemangioblastoma (CHB) is a benign, highly vascularized tumor that generally occurs in the central nervous system either in the setting of von Hippel-Lindau (VHL) disease or, more often, as a solitary sporadic lesion that is increasingly recognized in extraneural sites. We present the case of a 72-year-old woman with low back pain and a well-demarcated lytic lesion of the sacrum, which at histological and ultrastructural examination was indistinguishable from central nervous system CHB. The patient had no signs of VHL disease and died of another cause with no evidence of disease 57 months after curettage of the lesion. To our knowledge, this is the second case of CHB reported to occur in bone.

Emerging role of Notch signaling in epidermal differentiation and skin cancer.

Signaling mediated by the Notch receptor governs tissue development during embryonal organogenesis, while in adult tissues it contributes to maintenance of cellular differentiation, proliferation and apoptosis. In addition, control by the Notch pathway of stem cell self-renewal and multi-potency points to an expanding role of Notch signaling in the progression of solid tumors. Notch and its ligands are abundantly expressed in the epidermis, where Notch signaling functions as a molecular switch that intervenes in cell transition between different skin layers during the epidermal differentiation process. More recent findings obtained in melanoma and non-melanoma skin cancers show that Notch signaling has a dual action (either as an oncogene or as a tumor suppressor), depending on the tumor cell type and the synchronous activation of other intracellular signaling mechanisms. In this Review, we highlight the pleiotropic roles of the Notch signaling pathway in normal skin homeostasis and differentiation and focus on its altered regulation in the tumorigenesis of melanoma and non-melanoma skin cancer. Further understanding of the roles of Notch signaling in specific skin cancer types may provide a rationale for novel Notch-based therapeutic strategies.

Purpura-associated congenital lymphedema.

An 8-year-old girl referred to our Department for a two-month worsening of congenital primary lymphedema of the lower limb and for the appearance of several purpuric lesions on the right thigh and knee. We diagnosed a lichenoid pigmented purpura of Gougerot and Blum in a patient with Milroy disease, complicated by an insufficiency of anterior saphena. We treated the patient with topical steroids and compression stockings, until surgical intervention of phlebectomy. We report this case for the rarity of the disease, for the even more rare association with lichenoid pigmented purpura and for cutaneous immunopathological findings.

Expression of Notch-1 and alteration of the E-cadherin/beta-catenin cell adhesion complex are observed in primary cutaneous neuroendocrine carcinoma (Merkel cell carcinoma).

Increasing evidence indicates that Notch signaling contributes to physiological processes, including development and differentiation, as well as tumorigenesis, either as a tumor promoter or suppressor, depending on cellular context, expression levels and cross talk with other signaling systems. Recent studies reported absent or minimal Notch-1 expression in neuroendocrine tumors of the lung and gastrointestinal tract, suggesting a tumor-suppressor function of Notch-1. Merkel cell carcinoma is a rare and highly aggressive primary cutaneous neuroendocrine carcinoma. Because no information is available on Notch-1 expression in this tumor, we have investigated a series of 31 Merkel cell carcinoma for Notch-1 immunoreactivity. Immunoreactivities for E-cadherin and beta-catenin were also analyzed. All but 1 Merkel cell carcinoma (30 of 31) retained cytoplasmic and membrane Notch-1 expression in more than 50% of cells. beta-Catenin displayed a prevalent membrane-associated staining in 30 of 31 cases, and 22 cases showed more than 50% of immunoreactive cells whereas nuclear beta-catenin was seen only in 2 of 31 cases. E-cadherin membranous expression was remarkably low, as only 1 of 26 cases was found positive in more than 50% of cells. In contrast with neuroendocrine tumors in other tissues, evident Notch-1 expression was found in Merkel cell carcinoma. This finding does not support a tumor-suppressor function of Notch-1 in Merkel cell carcinoma. Downregulation of E-cadherin and diffuse membranous beta-catenin expression suggest a dysregulation of the E-cadherin/beta-catenin complex in Merkel cell carcinoma. This may contribute to local invasion and distant metastasis.

Inducible nitric oxide synthase expression in melanoma: implications in lymphangiogenesis.

Cutaneous melanoma preferentially metastasizes via the lymphatic route. However, the mechanisms of lymphatic invasion and metastasis to regional lymph nodes are poorly understood. Nitric oxide is a free radical molecule synthesized from L-arginine by nitric oxide synthases that plays a critical role in various physiological and pathological processes, including tumor growth and angiogenesis. We have tested whether inducible nitric oxide synthase expression correlates with lymphatic vessel density identified with D2-40 antibody and/or blood microvessel density identified with CD105/endoglin in a series of melanocytic nevi (n=28) and cutaneous melanomas (n=38), representative of various pT. Inducible nitric oxide synthase expression was significantly lower in melanocytic nevi in comparison with primary and metastatic melanomas (P<0.001). Mean microvessel density was significantly higher in primary and metastatic melanomas in comparison with melanocytic nevi (P<0.001 for intratumoral and P=0.001 for peritumoral vessels). Vertical growth phase melanomas showed a higher intratumoral microvessel density in comparison with radial growth phase melanomas (P=0.02). The number of peritumoral lymphatics was significantly lower in nevi as compared with primary and metastatic melanomas (P=0.01). No correlation between microvessel or lymphatic vessel and clinical outcome was found in melanomas. A significant direct correlation was observed between inducible nitric oxide synthase immunostaining in melanocytic tumor cells and the density of lymphatic vessels (peritumoral: P=0.001; intratumoral: P=0.08), and the density of peritumoral blood microvessel (P=0.02). Our findings support the hypothesis that inducible nitric oxide synthase is implicated not only in blood, but also in lymphatic vascular neoformation in melanoma. Mechanistic studies are needed to address the possibility that inducible nitric oxide synthase controls lymphangiogenesis, dissemination and lymphatic borne metastases.

Photoexposition discriminates Notch 1 expression in human cutaneous squamous cell carcinoma.

The Notch signaling pathway may play opposing roles in cancer. It can be oncosuppressive or protumoral, depending on the cellular and tissue context. In skin cancer, Notch 1 expression is downregulated, thus supporting the hypothesis of an oncosuppressive role in cutaneous carcinomas. However, as members of the Notch family undergo downregulation upon exposure to UV irradiation, we wondered whether Notch 1 expression in skin carcinomas may be governed by additional factors, including UV exposure. We investigated the expression of Notch 1 and its ligands, Jagged 1, Jagged 2 and Delta-like 1, by immunohistochemistry in a series of premalignant and invasive cutaneous carcinomas, including 4 solar keratoses, 5 Bowen's disease, 5 squamous cell carcinomas on sun-exposed skin, 6 squamous cell carcinomas on sun-protected genital skin and 14 basal cell carcinomas of different histotypes (nodular, superficial type, sclerodermiform/infiltrating and baso-squamous). Expression of Notch 1 was decreased in solar keratoses and invasive squamous cell carcinomas localized on sun-exposed skin. In contrast, marked Notch 1 staining was observed in extragenital Bowen's disease as well as in genital (penile) human papilloma virus-related in situ and invasive squamous cell carcinomas. A diffuse Notch 1 staining was detected in nodular and superficial basal cell carcinomas while sclerodermiform/infiltrating and baso-squamous basal cell carcinomas showed a low to absent Notch 1 expression. Jagged 1, Jagged 2 and Delta-like 1 proteins were expressed in all tissues examined. Present findings show divergent expression of Notch 1 in skin cancer, depending on anatomical site and tumor histotype. Thus, whereas in UV-related squamous cell photocarcinogenesis Notch 1 downregulation could mirror a tumor suppressor function of the receptor, in sun-protected squamous cell carcinomas Notch 1 was upregulated. Furthermore, Notch 1 expression was minimal in basal cell carcinoma subtypes correlated with risk of recurrence (sclerodermiform/infiltrating and baso-squamous) in comparison with nodular and superficial types.

The Wilms' tumor suppressor WT1 is associated with melanoma proliferation.

Expression of the Wilms' tumor suppressor WT1 has been demonstrated in a variety of tumors and tumor cell lines, e.g., in breast cancer and melanoma cell lines. Its role is controversial, with evidence for both tumor-promoting and tumor-suppressing activities. In this paper, we show that WT1 is expressed in malignant melanoma in >80% of the tumor cells, but not in normal skin or benign melanocytic nevi in vivo. We detected an unusual shift of WT1 isoforms towards WT1(+17AA/+KTS) in melanoma. WT1 shared an overlapping expression with proliferating nuclear cell antigen and with Nestin and Zyxin, which are involved in melanoma cell proliferation. To investigate whether WT1 is directly involved in melanoma cell proliferation, we made use of an RNAi approach in vitro. WT1 silencing significantly reduced the expression of Nestin and Zyxin and resulted in inhibition of melanoma cell proliferation as determined by a reduced BrdU incorporation. These findings suggest a direct role of WT1 in melanoma proliferation, which might be mediated via Nestin and Zyxin. Furthermore, expression of WT1 in vivo clearly discriminates between benign acquired nevi and malignant melanomas and appears to be correlated with melanocytic atypia and malignancy.

Early gastric carcinoma with oncocytic features and extensive metastases.

We present the case of a 63-year-old Caucasian woman with early gastric adenocarcinoma, suffering from extensive metastases at the time of initial presentation. Microscopic examination of the gastrectomy specimen revealed an invasive adenocarcinoma with oncocytic features. Interestingly, despite the fact that the carcinoma was pT1, it also was found to be N2, stage IV. The biologic behavior of oncocytic adenocarcinoma of the stomach is still unclear. We would like to present this case, so that its clinicopathological characteristics can be added to the few cases already published.

A new concept of melanocytic neoplasia pathogenesis based on the phenotype of common acquired nevi.

Common melanocytic nevi are ubiquitous lesions which in some cases constitute a risk factor for the development of melanoma. To date, despite long term research there are no known molecular hallmarks for nevus development. We have observed that common acquired nevi excised from the same individual share remarkable similarity in their microscopic appearance and in the immunohistochemical expression of E-cadherin. Based on these observations, we hypothesize that all melanocytes are genetically similar in the same individual and changes predisposing to neoplasia are a global melanocytic event characteristic for each person and propose a microgenomics/proteomics approach to test this hypothesis.

Chondrosarcoma of the spine: a rare case with unusual presentation.

Chondrosarcoma is the third most common primary malignancy of bone, affecting primarily the pelvic and shoulder girdles and being extremely rare in the spine. Herein, we present a case of a 65-year-old woman with a rare chondrosarcoma of the spine, who presented with clinical symptoms from the lung metastasis. The neoplasm was grade II and exhibited overexpression of the p53 tumor suppressor protein. The latter has been associated with a high propensity for distant metastases.

Ectopic modified sebaceous glands in human penis.

The balanopreputial sulcus is believed to be the most frequent site of the so-called Tyson's glands. The intriguing feature of these anatomical structures is their mere existence, which has been doubted. Herein, the authors present a case of a 24-year-old man who underwent surgical treatment of his phimosis. On microscopic examination of the specimen, glands with morphological features similar to those described by Tyson were noted.

Melanosis intestini: case report.

The term melanosis in the gastrointestinal tract refers to the accumulation of pigment deposits in the mucosa. Melanosis of the colon is not uncommon and has been associated with certain conditions, however melanosis of the small intestine is extremely rare. Herein, we describe a case in which we observed melanosis not only in the colon, but in the terminal ileum as well, associated with the use of anthraceneline laxatives. The clinical significance of this condition is not clear, however Gastroenterologists and Pathologists should be aware of its existence.