Shared Oncogenic Pathways Implicated in Both Virus-Positive and UV-Induced Merkel Cell Carcinomas

Merkel cell carcinoma (MCC) is a highly malignant neuroendocrine tumor of the skin whose molecular pathogenesis is not completely understood, despite the role that Merkel cell polyomavirus can play in 55-90% of cases. To study potential mechanisms driving this disease in clinically characterized cases, we searched for somatic mutations using whole-exome sequencing, and extrapolated our findings to study functional biomarkers reporting on the activity of the mutated pathways. Confirming previous results, Merkel cell polyomavirus-negative tumors had higher mutational loads with UV signatures and more frequent mutations in TP53 and RB compared with their Merkel cell polyomavirus-positive counterparts. Despite important genetic differences, the two Merkel cell carcinoma etiologies both exhibited nuclear accumulation of oncogenic transcription factors such as NFAT or nuclear factor of activated T cells (NFAT), P-CREB, and P-STAT3, indicating commonly deregulated pathogenic mechanisms with the potential to serve as targets for therapy. A multivariable analysis identified phosphorylated CRE-binding protein as an independent survival factor with respect to clinical variables and Merkel cell polyomavirus status in our cohort of Merkel cell carcinoma patients.

Mitoserate beim primären Melanom: Interobserver- und Intraobserver-Reproduzierbarkeit am HE-Schnitt und in der Immunhistologie

HINTERGRUND

Die Melanomklassifikation wurde 2009 durch die AJCC revidiert. Für die Klassifizierung primärer Melanome wurde als dritte Größe neben Tumordicke und Ulzeration die Angabe der Mitoserate neu eingeführt. Gemäß der AJCC-2009-Klassifikation des Melanoms führt der Nachweis nur einer oder mehrerer dermaler Tumormitosen bei Melanomen ≤ 1,0 mm Tumordicke zu einer Umgruppierung des Tumors von T1a nach T1b. Dies erklärt, wie wichtig die Frage nach der Reproduzierbarkeit dieses neuen Parameters ist.

METHODEN

Zur Prüfung der Interobserver-Reproduzierbarkeit der Mitoserate haben 17 Dermatopathologen und Pathologen, die in der Befundung des kutanen Melanoms sehr erfahren sind, die Mitoserate in 15 dünnen Melanomen mit einer mittleren Tumordicke von 0,91 mm an demselben Tumorschnitt bestimmt. Die Mitoserate wurde am HE-Schnitt und immunhistologisch (IH) mittels des mitosespezifischen Antikörpers Phospho-Histon-H3 (Ser10) bestimmt. Fünf Befunder wiederholten die Bestimmung nach mehr als einem Jahr ohne Kenntnis ihres Vorbefundes zur Ermittlung der Intraobserver-Reproduzierbarkeit.

ERGEBNISSE

Die Interobserver-Reproduzierbarkeit der Mitoserate bei dünnen Melanomen ist unbefriedigend und unabhängig davon, ob die Mitoserate am HE-Schnitt oder am immungefärbten Schnitt bestimmt wird (κ-Werte: 0,088 [HE] bzw. 0,154 [IH]). Bei einer Diskriminationsschwelle von 0/1 vs. 2+ Mitosen verbesserte sich der κ-Wert auf 0,345 (HE) bzw. 0,403 (IH). Die Intraobserver-Reproduzierbarkeit lag mit κ-Werten zwischen 0,18 und 0,348 je nach Befunder ebenfalls im unbefriedigenden Bereich.

DISKUSSION

Wegen der unbefriedigenden Reproduzierbarkeit und der großen Variation der Befunde zur Mitoserate bleibt es zweifelhaft, ob dieser Befund als Grundlage für Therapieentscheidungen herangezogen werden kann.

Autologous blood preparations rich in platelets, fibrin and growth factors

OBJECTIVES

Bone regeneration is often needed prior to dental implant treatment due to the lack of adequate quantity and quality after infectious diseases. The greatest regenerative power was obtained with autologous tissue, primarily the bone alive, taken from the same site or adjacent sites, up to the use centrifugation of blood with the selection of the parts with the greatest potential regenerative. In fact, various techniques and technologies were chronologically successive to cope with an ever better preparation of these concentrates of blood. Our aim is to review these advances and discuss the ways in which platelet concentrates may provide such unexpected beneficial therapeutic effects.

METHODS

The research has been carried out in the MEDLINE and Cochrane Central Register of Controlled Trials database by choosing keywords as "platelet rich plasma", "platelet rich fibrin", "platelet growth factors", and "bone regeneration" and "dentistry".

RESULTS

Autologous platelet rich plasma is a safe and low cost procedure to deliver growth factors for bone and soft tissue healing.

CONCLUSION

The great heterogeneity of clinical outcomes can be explained by the different PRP products with qualitative and quantitative difference among substance.

A morphological and immunophenotypic map of the immune response in Merkel cell carcinoma

The susceptibility of Merkel cell carcinoma to the host immune response has prompted a search for effective immunotherapy. CD8-positive T lymphocytes are considered key effectors of this response, but the cellular infiltrates also harbor tumor-protective agents. By developing a comprehensive morphological and immunophenotypic map of tumor-infiltrating lymphocytes (TILS) in Merkel cell carcinoma, we aimed to establish a useful template for future studies. Twenty-two cases (mean age, 79years [range, 52-95]; male-female ratio, 10:12) were studied. TILS were categorized as brisk (7), nonbrisk (9), and absent(6). Merkel cell polyomavirus (MCPyV)-positive (16) and -negative (6) cases were included, as were those with pure (18) and combined (4) morphologies. One MCPyV+ case had undergone spontaneous regression. Immunohistochemical markers included CD3, CD4, CD8, CD20, CD68, FoxP3, PD-1, and CD123. Statistical analysis used Fisher exact tests and Spearman correlations. There was a significant correlation between brisk TILs and MCPyV+ status (P=.025). CD8+ T lymphocytes predominated, were present in significantly higher proportions in brisk infiltrates (P=.003), and showed a significant predilection for the intratumoral environment (P=.003). Immune inhibitors including T regulatory cells (FOXP3+) and PD-1+ "exhausted" immunocytes were present in lower proportions. Our findings support (1) the link between a brisk immune response and MCPyV positivity, (2) the supremacy of CD8+ cells in effecting immunity, and (3) the incorporation of immune inhibitors within the global infiltrate. Efforts to therapeutically arm the "effectors" and disarm the "detractors" are well focused. These will likely have the greatest impact on MCPyV-positive cases.

STAT3/5-Dependent IL9 Overexpression Contributes to Neoplastic Cell Survival in Mycosis Fungoides

PURPOSE

Sustained inflammation is a key feature of mycosis fungoides (MF), the most common form of cutaneous T-cell lymphoma (CTCL). Resident IL9-producing T cells have been found in skin infections and certain inflammatory skin diseases, but their role in MF is currently unknown.

EXPERIMENTAL DESIGN

We analyzed lesional skin from patients with MF for the expression of IL9 and its regulators. To determine which cells were producing IL9, high-throughput sequencing was used to identify malignant clones and Vb-specific antibodies were employed to visualize malignant cells in histologic preparations. To explore the mechanism of IL9 secretion, we knocked down STAT3/5 and IRF4 by siRNA transfection in CTCL cell lines receiving psoralen+UVA (PUVA) ± anti-IL9 antibody. To further examine the role of IL9 in tumor development, the EL-4 T-cell lymphoma model was used in C57BL/6 mice.

RESULTS

Malignant and reactive T cells produce IL9 in lesional skin. Expression of the Th9 transcription factor IRF4 in malignant cells was heterogeneous, whereas reactive T cells expressed it uniformly. PUVA or UVB phototherapy diminished the frequencies of IL9- and IL9r-positive cells, as well as STAT3/5a and IRF4 expression in lesional skin. IL9 production was regulated by STAT3/5 and silencing of STAT5 or blockade of IL9 with neutralizing antibodies potentiated cell death after PUVA treatment in vitro IL9-depleted mice exhibited a reduction of tumor growth, higher frequencies of regulatory T cells, and activated CD4 and CD8 T lymphocytes.

CONCLUSIONS

Our results suggest that IL9 and its regulators are promising new targets for therapy development in mycosis fungoides. Clin Cancer Res; 22(13); 3328-39. ©2016 AACR.

Genomic aberrations in spitzoid melanocytic tumours and their implications for diagnosis, prognosis and therapy

Histopathological evaluation of melanocytic tumours usually allows reliable distinction of benign melanocytic naevi from melanoma. More difficult is the histopathological classification of Spitz tumours, a heterogeneous group of tumours composed of large epithelioid or spindle-shaped melanocytes. Spitz tumours are biologically distinct from conventional melanocytic naevi and melanoma, as exemplified by their distinct patterns of genetic aberrations. Whereas common acquired naevi and melanoma often harbour BRAF mutations, NRAS mutations, or inactivation of NF1, Spitz tumours show HRAS mutations, inactivation of BAP1 (often combined with BRAF mutations), or genomic rearrangements involving the kinases ALK, ROS1, NTRK1, BRAF, RET, and MET. In Spitz naevi, which lack significant histological atypia, all of these mitogenic driver aberrations trigger rapid cell proliferation, but after an initial growth phase, various tumour suppressive mechanisms stably block further growth. In some tumours, additional genomic aberrations may abrogate various tumour suppressive mechanisms, such as cell-cycle arrest, telomere shortening, or DNA damage response. The melanocytes then start to grow in a less organised fashion and may spread to regional lymph nodes, and are termed atypical Spitz tumours. Upon acquisition of even more aberrations, which often activate additional oncogenic pathways or alter cell differentiation, the neoplastic cells become entirely malignant and may colonise and take over distant organs (spitzoid melanoma). The sequential acquisition of genomic aberrations suggests that Spitz tumours represent a continuous biological spectrum, rather than a dichotomy of benign versus malignant, and that tumours with ambiguous histological features (atypical Spitz tumours) might be best classified as low-grade melanocytic tumours. The number of genetic aberrations usually correlates with the degree of histological atypia and explains why existing ancillary genetic techniques, such as array comparative genomic hybridisation (CGH) or fluorescence in situ hybridisation (FISH), are usually capable of accurately classifying histologically benign and malignant Spitz tumours, but are not very helpful in the diagnosis of ambiguous melanocytic lesions. Nevertheless, we expect that progress in our understanding of tumour progression will refine the classification of spitzoid melanocytic tumours in the near future. By integrating clinical, pathological, and genetic criteria, distinct tumour subsets will be defined within the heterogeneous group of Spitz tumours, which will eventually lead to improvements in diagnosis, prognosis and therapy.

A waterborn zoonotic helminthiase in an Italian diver: a case report of a cutaneous Sparganum infection and a review of European cases

Many waterborne helminthes are opportunistic parasites that can travel directly from animals to man and may contain forms capable of penetrating the skin. Among these, Sparganum is the pseudophyllidean tapeworm that belongs to the genus Spirometra, which is responsible for parasitic zoonosis; it is rarely detected in Europe and is caused by the plerocercoid infective larva. Thus far, only six cases of cutaneous and ocular sparganosis have been reported in Europe; two and four cases have occurred in France and Italy, respectively. Herein, we describe a new case of sparganosis in Italy that affected a male diver who presented to the Bambino Gesù Children's Hospital of Rome. The patient's skin biopsy was submitted to the Parasitology department who, in consultation with Pathology, concluded that the morphologic and microscopic findings were those of Sparganum spp. larvae. The patient recovered following a single dose of 600 mg praziquantel.

[Merkel cell carcinoma]

Merkel cell carcinoma (MCC, cutaneous neuroendocrine carcinoma) is a rare form of tumor of unclear histogenesis which predominantly occurs in elderly patients on areas exposed to the sun. A higher incidence and occurrence in younger people is predominantly found in immunosuppressed persons which is why a pathogenetic role is also attributed to immunosuppression in addition to ultraviolet (UV) radiation. Additionally, in 80% of cases clonally integrated polyomavirus (Merkel cell polyomavirus, MCPyV) could be detected. Clinically MCC represents an uncharacteristic tumor. Histopathologically, monomorphic dermal and/or subcutaneous nodes are found consisting of round or oval medium sized cells with a vesicular nucleus and sparse cytoplasm. The neoplastic cells of MCC express cytokeratin (CK) 20 with a dot-like perinuclear accentuation. In addition, pan-CK, neuroendocrine markers (e.g. chromogranin A and synaptophysin), neurofilament proteins, CD56, CD57, Bcl-2, TdT and PAX-5 are immunohistochemically positive. In most cases CM2B4, an antibody against MCPyV is also positive. Expression of p63 has been observed in some of the cases and in some studies was associated with a favorable prognosis. The markers thyroid transcription factor 1, mammalian achaete scute complex like 1, vimentin, S-100 and CK7 are not normally expressed by MCC. The prognosis is primarily dependent on tumor size and the lymph node status. The presence of intralymphatic tumor complexes is associated with a higher rate of local recurrence and lymph node metastasis. A larger number of intratumoral cytotoxic T-lymphocytes is accompanied by a favorable prognosis and the presence of > 50% of K-67+ neoplastic cells with an unfavorable prognosis. Further morphological, phenotypical and genetic factors have not yet been validated in larger cohorts with respect to the prognostic relevance.

Kinase fusions are frequent in Spitz tumours and spitzoid melanomas

Spitzoid neoplasms are a group of melanocytic tumours with distinctive histopathological features. They include benign tumours (Spitz naevi), malignant tumours (spitzoid melanomas) and tumours with borderline histopathological features and uncertain clinical outcome (atypical Spitz tumours). Their genetic underpinnings are poorly understood, and alterations in common melanoma-associated oncogenes are typically absent. Here we show that spitzoid neoplasms harbour kinase fusions of ROS1 (17%), NTRK1 (16%), ALK (10%), BRAF (5%) and RET (3%) in a mutually exclusive pattern. The chimeric proteins are constitutively active, stimulate oncogenic signalling pathways, are tumourigenic and are found in the entire biologic spectrum of spitzoid neoplasms, including 55% of Spitz naevi, 56% of atypical Spitz tumours and 39% of spitzoid melanomas. Kinase inhibitors suppress the oncogenic signalling of the fusion proteins in vitro. In summary, kinase fusions account for the majority of oncogenic aberrations in spitzoid neoplasms and may serve as therapeutic targets for metastatic spitzoid melanomas.

Convergent mutations and kinase fusions lead to oncogenic STAT3 activation in anaplastic large cell lymphoma

A systematic characterization of the genetic alterations driving ALCLs has not been performed. By integrating massive sequencing strategies, we provide a comprehensive characterization of driver genetic alterations (somatic point mutations, copy number alterations, and gene fusions) in ALK(-) ALCLs. We identified activating mutations of JAK1 and/or STAT3 genes in ∼20% of 88 [corrected] ALK(-) ALCLs and demonstrated that 38% of systemic ALK(-) ALCLs displayed double lesions. Recurrent chimeras combining a transcription factor (NFkB2 or NCOR2) with a tyrosine kinase (ROS1 or TYK2) were also discovered in WT JAK1/STAT3 ALK(-) ALCL. All these aberrations lead to the constitutive activation of the JAK/STAT3 pathway, which was proved oncogenic. Consistently, JAK/STAT3 pathway inhibition impaired cell growth in vitro and in vivo.

Aggressive epidermotropic cutaneous CD8+ lymphoma: a cutaneous lymphoma with distinct clinical and pathological features. Report of an EORTC Cutaneous Lymphoma Task Force Workshop

AIMS

Aggressive epidermotropic cutaneous CD8(+) lymphoma is currently afforded provisional status in the WHO classification of lymphomas. An EORTC Workshop was convened to describe in detail the features of this putative neoplasm and evaluate its nosological status with respect to other cutaneous CD8(+) lymphomas.

METHODS AND RESULTS

Sixty-one CD8(+) cases were analysed at the workshop; clinical details, often with photographs, histological sections, immunohistochemical results, treatment and patient outcome were discussed and recorded. Eighteen cases had distinct features and conformed to the diagnosis of aggressive epidermotropic cutaneous CD8(+) lymphoma. The patients typically present with widespread plaques and tumours, often ulcerated and haemorrhagic, and histologically have striking pagetoid epidermotrophism. A CD8(+) /CD45RA(+) /CD45RO(-) /CD2(-) /CD5(-) /CD56(-) phenotype, with one or more cytotoxic markers, was found in seven of 18 patients, with a very similar phenotype in the remainder. The tumours seldom involve lymph nodes, but mucosal and central nervous system involvement are not uncommon. The prognosis is poor, with a median survival of 12 months. Examples of CD8(+) mycosis fungoides, lymphomatoid papulosis and Woringer-Kolopp disease presented the typical features well documented in the CD4(+) forms of those diseases.

CONCLUSIONS

Aggressive epidermotropic cutaneous CD8(+) lymphoma is a distinct lymphoma that warrants inclusion as a distinct entity in future revisions of lymphoma classifications.

The many clinico-pathologic faces of actinic keratosis: an atlas

Actinic keratoses (AKs) are intraepithelial neoplasms formed by atypical keratinocyte proliferation. Histopathologically, typical AKs are characterized by a slightly thickened epidermis, usually with irregular downward buds, orthokeratosis alternating with parakeratosis ('pink and blue') with loss of the underlying granular layer and a disarrangement of the epidermis with atypical keratinocytes at the basal layer. There are several histopathological variants of AK according to the different degrees of keratinocytic atypia, epidermal hyperplasia/atrophy, inflammation and pigmentation. Some authors consider AK an early in situ squamous cell carcinoma and propose a classification of AK based on the extent of atypical keratinocytes in the epidermis.