A. Carlotti

Merkel cell carcinoma of the skin: pathological and molecular evidence for a causative role of MCV in oncogenesis†

Merkel cell carcinoma (MCC), a skin tumour with neuroendocrine features, was recently found to be associated with a new type of human polyomavirus, called Merkel cell virus (MCV). We investigated the specificity of this association as well as a causal role of MCV in oncogenesis. DNA and RNA from ten cases of MCC were analysed using PCR and RT‐PCR. DNA from 1241 specimens of a wide range of human tumours was also analysed. The DIPS technique was used to identify the integration locus of viral DNA sequences. Array CGH was performed to analyse structural alterations of the cell genome. MCV DNA sequences were found in all ten cases of MCC and in none of the 1241 specimens of other tumour types. Clonal integration of MCV into the host genome was seen in all MCC cases and was checked by FISH in one case. A recurrent pattern of conserved viral sequences which encompassed the replication origin, the small tumour (ST), and the 5′ part of the large tumour (LT) antigen DNA sequences was observed. Both ST and LT viral sequences were found to be significantly expressed in all MCCs. Neither recurrent site of integration nor alteration of cellular genes located near the viral sequences was observed. The tight association of MCV with MCC, the clonal pattern of MCV integration, and the expression of the viral oncoproteins strongly support a causative role for MCV in the tumour process. This information will help the development of novel approaches for the assessment and therapy of MCC and biologically related tumours. Copyright

High Levels of Antibodies Against Merkel Cell Polyomavirus Identify a Subset of Patients With Merkel Cell Carcinoma With Better Clinical Outcome

PURPOSE A new human polyomavirus, Merkel cell polyomavirus (MCV), was identified in 2008 in tumor tissue of patients with Merkel cell carcinoma (MCC), a relatively rare human skin cancer. In this study, we investigated patients with MCC and controls for the presence of antibodies against MCV and their association with clinical characteristics. PATIENTS AND METHODS Antibodies against MCV were investigated by enzyme-linked immunosorbent assay in 68 patients with MCC and 82 controls using VP1 virus-like particles produced in insect cells. RESULTS Antibodies against MCV were detected in all patients with MCC and in 85% of controls. However, high antibody titers (> 10,000) were rarely observed in controls (7.3%) and they were detected in 64.7% of patients with MCC (P < .001) in contrast to the absence of VP1 expression in tumor samples. In addition, the geometric mean titer of anti-MCV in patients with MCC was around 14 times higher than that observed in MCV-positive controls (P < .001) and was not correlated with tumor viral load. High antibody titers were not found to be associated with any subject or tumor characteristics, but better progression-free survival was observed in patients with high antibody titers (hazard ratio, 4.6; 95% CI, 1.7 to 12.2; P = .002). CONCLUSION High titers of MCV antibodies in a much higher proportion of patients with MCC than in controls confirmed the association between MCV infection and MCC. The findings also indicated that a better progression-free survival occurred in patients with high MCV antibody titers and suggested that there are at least two distinct etiologic causes of MCC.

Distinct Merkel Cell Polyomavirus Molecular Features in Tumour and Non Tumour Specimens from Patients with Merkel Cell Carcinoma

Merkel Cell Polyomavirus (MCPyV) is associated with Merkel Cell carcinoma (MCC), a rare, aggressive skin cancer with neuroendocrine features. The causal role of MCPyV is highly suggested by monoclonal integration of its genome and expression of the viral large T (LT) antigen in MCC cells. We investigated and characterized MCPyV molecular features in MCC, respiratory, urine and blood samples from 33 patients by quantitative PCR, sequencing and detection of integrated viral DNA. We examined associations between either MCPyV viral load in primary MCC or MCPyV DNAemia and survival. Results were interpreted with respect to the viral molecular signature in each compartment. Patients with MCC containing more than 1 viral genome copy per cell had a longer period in complete remission than patients with less than 1 copy per cell (34 vs 10 months, P = 0.037). Peripheral blood mononuclear cells (PBMC) contained MCPyV more frequently in patients sampled with disease than in patients in complete remission (60% vs 11%, P = 0.00083). Moreover, the detection of MCPyV in at least one PBMC sample during follow-up was associated with a shorter overall survival (P = 0.003). Sequencing of viral DNA from MCC and non MCC samples characterized common single nucleotide polymorphisms defining 8 patient specific strains. However, specific molecular signatures truncating MCPyV LT were observed in 8/12 MCC cases but not in respiratory and urinary samples from 15 patients. New integration sites were identified in 4 MCC cases. Finally, mutated-integrated forms of MCPyV were detected in PBMC of two patients with disseminated MCC disease, indicating circulation of metastatic cells. We conclude that MCPyV molecular features in primary MCC tumour and PBMC may help to predict the course of the disease.

Granulomatous mycosis fungoides and granulomatous slack skin: a multicenter study of the Cutaneous Lymphoma Histopathology Task Force Group of the European Organization For Research and Treatment of Cancer (EORTC)

BACKGROUND Granulomatous cutaneous T-cell lymphomas (CTCLs) are rare and represent a diagnostic challenge. Only limited data on the clinicopathological and prognostic features of granulomatous CTCLs are available. We studied 19 patients with granulomatous CTCLs to further characterize the clinicopathological, therapeutic, and prognostic features. OBSERVATIONS The group included 15 patients with granulomatous mycosis fungoides (GMF) and 4 with granulomatous slack skin (GSS) defined according to the World Health Organization-European Organization for Research and Treatment of Cancer classification for cutaneous lymphomas. Patients with GMF and GSS displayed overlapping histologic features and differed only clinically by the development of bulky skin folds in GSS. Histologically, epidermotropism of lymphocytes was not a prominent feature and was absent in 9 of 19 cases (47%). Stable or progressive disease was observed in most patients despite various treatment modalities. Extracutaneous spread occurred in 5 of 19 patients (26%), second lymphoid neoplasms developed in 4 of 19 patients (21%), and 6 of 19 patients (32%) died of their disease. Disease-specific 5-year survival rate in GMF was 66%. CONCLUSIONS There are clinical differences between GMF and GSS, but they show overlapping histologic findings and therefore cannot be discriminated by histologic examination alone. Development of hanging skin folds is restricted to the intertriginous body regions. Granulomatous CTCLs show a therapy-resistant, slowly progressive course. The prognosis of GMF appears worse than that of classic nongranulomatous mycosis fungoides.

Progressive Upregulation of PD-1 in Primary and Metastatic Melanomas Associated with Blunted TCR Signaling in Infiltrating T Lymphocytes

Programmed death-1 (PD-1) is involved in T-cell tolerance to self-antigens. For some cancers, it has been suggested that the expression of a ligand of PD-1, namely PD-L1, could contribute to tumor escape from immune destruction. Nevertheless, the relationship between PD-1 expression on tumor-infiltrating T lymphocytes (TILs), disease stage, and TIL responsiveness is still poorly documented. In this study, we show that freshly isolated CD4(+) and CD8(+) TILs express substantial levels of PD-1 in primary melanomas. The expression of PD-1 was further increased at later stages in distant cutaneous metastases, especially on CD8(+) TILs. The expression of PD-1 ligands was frequent only in metastases, on both tumor cells and tumor-derived myeloid cells. TILs isolated from these cutaneous tumors are poorly reactive ex vivo, with blunted calcium response and IFN-γ production after TCR stimulation. Surprisingly, in distinct parts of a primary melanoma, either invasive or regressing, we show that TILs similarly express PD-1 and remain dysfunctional. The expressions of PD-1 and PD-L1 in metastatic melanoma lesions could be considered as witnesses of an unsuccessful anti-tumoral immune response, but the direct involvement of PD-1 in the severity of the disease, and the importance of TILs in tumor regression, remain to be established.

Histologic and Immunohistologic Characterization of Skin Localization of Myeloid Disorders

A retrospective analysis of 173 skin biopsy specimens of myeloid leukemia cutis (MLC) was performed to determine histologic and immunophenotypic criteria that could distinguish the varied myeloid disorders from one another. For the study, 11 relevant histologic items were scored and 12 antigens were studied (CD68 [KP1], CD163, CD14, CD4, myeloperoxidase [MPO], CD33, CD117, CD34, CD56, MIB-1, CD303, and CD123). Underlying myeloid disorders were essentially acute myeloid leukemias (65.3%), chronic myelomonocytic leukemias (11.0%), and refractory anemia (10.4%). Skin lesions were de novo in 7.5%, concurrent in 26.6%, and subsequent in 60.7%. Several morphologic characteristics (density, size of tumor cells, inflammatory background) were statistically useful in distinguishing between varied myeloid disorders. De novo MLCs displayed a specific morphologic profile. Association of CD68, CD33, and MPO could diagnose 100% of the cases of MLC. However, the immunohistochemical panel could not distinguish between the varied underlying myeloid disorders, with the exception that CD123 was particularly powerful in recognizing chronic myelomonocytic leukemia and also permitted reclassification of 4 cases as blastic plasmacytoid dendritic cell neoplasm.

Autoimmune Bullous Skin Diseases Occurring under Anti-Tumor Necrosis Factor Therapy: Two Case Reports

Background: Anti-tumor necrosis factor (TNF) agents are increasingly being used for a rapidly expanding number of rheumatic and systemic diseases. As a result of this use, and of the longer follow-up periods of treatment, there are a growing number of reports of the development of autoimmune processes related to anti-TNF agents. The use of anti-TNF agents has been associated with more and more cases of autoimmune diseases, principally cutaneous vasculitis, lupus-like syndrome, systemic lupus erythematosus and interstitial lung disease. Observations: We report 2 cases of autoimmune bullous skin disease occurring in patients undergoing TNF-targeted therapy: a bullous pemphigoid and a pemphigus foliaceus. Both patients were treated by anti-TNF agents for rheumatoid arthritis and showed improvement following interruption of that treatment. Here, we discuss the relationship between anti-TNF therapy and the occurrence of autoimmune bullous disease. Conclusion: Anti-TNF agents should be considered as a potential cause of drug-induced autoimmune bullous skin disease.

Specific skin lesions in chronic myelomonocytic leukemia: a spectrum of myelomonocytic and dendritic cell proliferations: a study of 42 cases.

Chronic myelomonocytic leukemia (CMML) is a rare clonal hematopoietic disorder that can also involve the skin. The histopathology of these skin lesions is not clearly defined, and few data are available in the literature. To better understand tumoral skin involvements in CMML we carried out an extensive, retrospective clinicopathologic study of 42 cases selected from the database of the French Study Group of Cutaneous Lymphomas. On the basis of clinical data, morphology, and phenotype we identified 4 clinicopathologic profiles representing 4 distinct groups. The first group comprised myelomonocytic cell tumors (n=18), exhibiting a proliferation of granulocytic or monocytic blast cells, which were CD68 and/or MPO positive but negative for dendritic cell markers. The second group comprised mature plasmacytoid dendritic cell tumors (n=16), denoted by a proliferation of mature plasmacytoid dendritic cells, which were CD123, TCL1, and CD303 positive but CD56, CD1a, and S100 negative. The third group comprised blastic plasmacytoid dendritic cell tumors (n=4), characterized by a proliferation of monomorphous medium-sized blast cells, which were CD4, CD56, CD123, TCL1 positive but CD1a and S100 negative. The fourth group consisted of a putatively novel category of tumor that we named blastic indeterminate dendritic cell tumors (n=4), distinguished by a proliferation of large blast cells that not only exhibited monocytic markers but also the dendritic markers CD1a and S100. These 4 groups showed distinctive outcomes. Finally, we showed, by fluorescence in situ hybridization analysis, a clonal link between bone marrow disease and skin lesions in 4 patients. Herein, we have described a novel scheme for pathologists and physicians to handle specific lesions in CMML, which correspond to a spectrum of myelomonocytic and dendritic cell proliferations with different outcomes. A minimal panel of immunohistochemical markers including CD68, CD1a, S100, Langerin, and CD123 is necessary to make the correct classification in this spectrum of cutaneous CMML tumors, in which dendritic cell lineage plays an important role.

Epidermodysplasia verruciformis in human immunodeficiency virus-infected patients: a marker of human papillomavirus-related disorders not affected by antiretroviral therapy.

BACKGROUND Skin eruptions resembling epidermodysplasia verruciformis (EV) are rarely observed in immunocompromised patients. We focused on the epidemiologic, clinical, virologic, and immunologic features of EV in human immunodeficiency virus (HIV)-positive patients. OBSERVATIONS We studied 11 HIV-positive patients (6 men and 5 women) with clinical and histological features of EV observed at our department. The median age at HIV diagnosis was 27 years. At the onset of eruption, the median age was 40 years and the median CD4 T-cell count was 170/μL. Clinical presentation included flat warts (n = 11), pityriasis versicolor-like macules (n = 5), and lichenoid papules (n = 3) on sun-exposed skin. Detection and typing of cutaneous human papillomavirus (HPV) were carried out in 8 cases and always revealed β-HPV infection, including oncogenic HPV-5 or 8 (n = 6). Mucosal HPV-related diseases were present in 7 cases. Histories of skin cancer and lymphoproliferative disorder were recorded in 3 and 4 patients, respectively, including 2 fatal cases. Skin eruption was never improved by highly active antiretroviral therapy (HAART). In 2 cases, EV was associated with an immune reconstitution syndrome. The present series is the largest with a complete characterization. A review of similar cases was carried out. CONCLUSION Despite effective HAART, HIV-infected patients with EV require a prolonged and careful follow-up to detect mucosal HPV-related diseases, lymphoproliferative disorders, and skin cancers.

Brief reportNeutrophilic panniculitis

Neutrophilic (lobular) panniculitis (NP) is a very rare condition that belongs to the group of neutrophilic dermatoses. We report the case of a patient with NP and review the relevant literature. NP appears as a subcutaneous nodular eruption. Histology shows a lobular neutrophilic infiltrate. NP must be differentiated from other types of panniculitis, and also from the subcutaneous septal involvement that may occur in some cases of Sweets syndrome and from erythema nodosum. NP is significantly associated with myelodysplasia. It is highly sensitive to oral steroid therapy.