Detection of Merkel cell polyomavirus and human papillomaviruses in Merkel cell carcinoma combined with squamous cell carcinoma in immunocompetent European patients.

Background: About 10% of patients with Merkel cell carcinoma (MCC) suffer from an associated squamous cell carcinoma (SCC). In European patients, Merkel cell polyomavirus (MCPyV) is detectable in 60%-88% of the MCC tumors. In combined lesions, MCPyV was not detectable so far.

Merkel cell polyomavirus is present in common warts and carcinoma in situ of the skin.

Polyomaviruses have been linked to diseases of immunosuppressed patients. We sought to determine the prevalence of Merkel cell polyomavirus in benign epithelial skin neoplasms and nonmelanoma skin cancer of immunosuppressed renal transplant recipients and long-term dialysis patients. Merkel cell polyomavirus DNA was detected by polymerase chain reaction (PCR) in 2 (10%) of 20 patients, in carcinomas in situ (Bowen's disease).

Inflammatory monocytes are a reservoir for Merkel cell polyomavirus.

Merkel cell polyomavirus (MCPyV) is a recently discovered virus that is implicated in the oncogenesis of Merkel cell carcinoma (MCC). The route of dissemination and the reservoir(s) of MCPyV within the human body have not yet been identified. In this study we describe two patients with multiple MCPyV-positive inflammatory and neoplastic skin lesions at different anatomic sites.

Borrelia in granuloma annulare, morphea and lichen sclerosus: a PCR-based study and review of the literature.

Background: Morphea, granuloma annulare (GA) and lichen sclerosus et atrophicans (LSA) have also been suggested to be linked to Borrelia infection. Previous studies based on serologic data or detection of Borrelia by immunohistochemistry and polymerase chain reaction (PCR) reported contradictory results. Thus, we examined skin biopsies of morphea, GA and LSA by PCR to assess the prevalence of Borrelia DNA in an endemic area and to compare our results with data in the literature.

Apoptosis in CD30-positive lymphoproliferative disorders of the skin.

The spectrum of CD30-positive cutaneous lymphoproliferative disorders (CD30+ CLPD) includes lymphomatoid papulosis (LyP), primary cutaneous CD30+ large T-cell lymphoma (LTCL) and rare borderline patients. Despite their malignant histopathology, CD30+ CLPD exhibit a low-grade malignant course with an excellent prognosis and a characteristic tendency for spontaneous regression. Apoptosis of tumour cells is considered a principal mechanism of tumour regression.

Hepatitis C and G viruses in B-cell lymphomas of the skin.

Background: The etiology of B-cell lymphoproliferative disorders (LPDs) of the skin has still to be elucidated. So far, Borrelia sp. has been identified as the causative agent of some cases of B-cell LPDs of the skin.

Study of HHV-8 DNA sequences in archival biopsies from lesional skin of Kaposi's sarcoma, various mesenchymal tumors and related reactive conditions.

Background: HHV-8 has been identified as the causative agent of Kaposi's sarcoma (KS) and some lymphoproliferative disorders. In addition, there are anecdotal reports on the presence of HHV-8 in other tumors, especially cutaneous epithelial and mesenchymal neoplasms. The aim of the study was to ascertain the value of identification of HHV-8 viral DNA sequences in routinely processed, formalin-fixed, paraffin-embedded tissues for the diagnosis of Kaposi's sarcoma and other mesenchymal tumors.