Search results for "Merkel"
showing 10 items of 45 documents
Cytokeratins in the Histological Diagnosis of Malignant Tumors
1994
Cytokeratins, which comprise a multigene family of 20 related polypeptides (CKs 1–20), are constituents of the intermediate filaments of epithelial cells, in which they are expressed in various combinations depending on the epithelial type and the degree of differentiation. Of these, CK 19 (400 amino acids; 44.1 kilodaltons) is an example of a widely distributed CK, being expressed in various epithelia, including many simple epithelia. In contrast, the recently identified CK 20 (424 amino acids; 48.6 kilodaltons) is essentially confined to gastrointestinal epithelia, the urothelium and Merkel cells. The differential expression of individual CKs in various types of carcinomas makes them use…
Immune checkpoint blockade for Merkel cell carcinoma: actual findings and unanswered questions
2019
Purpose: Merkel cell carcinoma (MCC) is a rare, aggressive neuroendocrine carcinoma arising from the skin. We aimed to review and deal with some of the most relevant controversial topics on the correct use of immunotherapy for the treatment of MCC. Methods: The primary search was carried out via PubMed, EMBASE, and the Cochrane Library (until 31st May, 2018), while other articles and guidelines were retrieved from related papers or those referenced in these papers. Additionally, we performed an extensive search on ClinicalTrials.gov to gather information on the ongoing clinical trials related to this specific topic. Results: We performed an up-to-date critical review taking into account the…
Immune checkpoint inhibition therapy for advanced skin cancer in patients with concomitant hematological malignancy: a retrospective multicenter DeCO…
2020
BackgroundSkin cancers are known for their strong immunogenicity, which may contribute to a high treatment efficacy of immune checkpoint inhibition (ICI). However, a considerable proportion of patients with skin cancer is immuno-compromised by concomitant diseases. Due to their previous exclusion from clinical trials, the ICI treatment efficacy is poorly investigated in these patients. The present study analyzed the ICI treatment outcome in advanced patients with skin cancer with a concomitant hematological malignancy.MethodsThis retrospective multicenter study included patients who were treated with ICI for locally advanced or metastatic melanoma (MM), cutaneous squamous cell carcinoma (cS…
A thoracic vertebral localization of a metastasized cutaneous Merkel cell carcinoma: Case report and review of literature
2017
Background: Merkel cell carcinoma (MCC) is a rare neuroendocrine skin tumor, which may be related to sun exposure. It can metastasize to lungs, liver and bone, leading to severe morbidity and mortality. Vertebral metastases from MCC are rare. The authors report the tenth case in the literature, a 59-year-old patient with MCC, which was primarily localized in the scalp, and later provoked distant metastasis to the thoracic spinal column. Case Description: A 59-year-old woman was admitted at our Unit of Neurosurgery with a 4-month history of progressive and severe dorsal back pain, without neurological signs. The patient had been surgically treated for a recidivated MCC in the occipital regio…
Special Program of Differentiation Expressed in Keratinocytes of Human Haarscheiben: An Analysis of Individual Cytokeratin Polypeptides
1993
Human haarscheiben, epidermal Merkel cell-rich sensory organs of hairy skin, were studied for the expression of various cytokeratin (CK) polypeptides and other epithelial and neuronal differentiation markers by applying immunoperoxidase and immunofluorescence microscopy to frozen sections and by two-dimensional gel electrophoresis. The basal clusters of Merkel cells were specifically detected by antibodies against CK 20. Haarscheiben keratinocytes were unique mainly by the prominent expression of CK 17 in the lower and middle layers. Further differences as compared to keratinocytes of usual epidermis included the enlargement of the basal compartment, characterized by the expression of CK 5 …
Immunohistological and immunoelectron microscopic identification of TNF alpha in normal human and murine epidermis.
1992
The presence, distribution and cellular localization of tumour necrosis factor-alpha (TNF alpha) were investigated in normal human and murine epidermis using immunohistological and immunoelectron microscopic methods with monoclonal and polyclonal antibodies. The immunostaining revealed an intercellular plasma membrane and cytoplasmic labelling of the epidermal keratinocytes, but no labelling of Langerhans cells, melanocytes and Merkel cells. Large amounts of TNF alpha were regularly found in the sebaceous glands. These findings demonstrate that epidermal keratinocytes and especially sebocytes produce and release TNF alpha and that this keratinocyte-derived cytokine may be important for the …
Upper lip malignant neoplasms : a study of 59 cases
2011
Objectives: To present the demographic data, clinico-pathologic features and therapeutic outcome of a series of upper lip malignancies. Study Design: Retrospective study at a single Cancer Institution in Mexico City during a 14-year period. Results: There were 59 cases, (30 males and 29 females); age range: 14 to 106 years (mean: 73 yr.). Antecedents of ultraviolet light and tobacco exposure were found in 20 (33.9%) and 16 cases (27%) respectively. There were 35 squamous cell carcinomas (59.3%), 19 basal cell carcinomas (32.2%) and one case each (1.7%) of adenocarcinoma NOS, adenoid cystic carcinoma, angiosarcoma, Merkel cell carcinoma and melanoma. There were 14 cases in stage I (23.7%), 1…
Cytokeratin 20 Is a General Marker of Cutaneous Merkel Cells While Certain Neuronal Proteins Are Absent
1995
Merkel cells are difficult to identify in tissue sections. Previous studies have used cytokeratins (CK) 8, 18, and 19 as histologic markers of Merkel cells. However, these CKs are also expressed in some outer root sheath keratinocytes and some early fetal epidermal cells and thus are not truly specific of Merkel cells in general. Using selective antibodies against a newly described CK, number 20--originally found in intestinal epithelium and Merkel cell carcinomas--in comparison to a key protein of neuroendocrine cells, chromogranin A, we established CK 20 as a specific Merkel cell marker in skin of humans, pigs, and mice. CK 20 seems to be an even more general and sensitive Merkel cell mar…
Le Istituzioni di Gaio e il Glücksstern di Niebuhr
2012
Sulla base della documentazione manoscritta, anche inedita, e di altre fonti si ripercorrono le vicende che portarono nel 1816 Barthold Georg Niebuhr a scoprire il palinsesto delle Istituzioni di Gaio nella Biblioteca Capitolare di Verona e si discute criticamente la casualità di tale scoperta.
Unusual Neuroendocrine Differentiation in a Small Round Cell Angiosarcoma: A Potential Histologic Mimicker of Superficial Ewing Sarcoma.
2018
Neuroendocrine differentiation or aberrant expression of neuroendocrine markers is very uncommon in angiosarcomas (AS) and creates a challenging differential diagnosis with other superficial or soft tissue tumors. Herein, we report a new case of superficial AS presenting as a tumor lesion on the little finger of the right hand of a 52-year-old man. The tumor displayed CD56, chromogranin-A, and synaptophysin immunoreactivity. Tumor cells were positive for vascular markers (CD31, FLI1, ERG, D2-40, VE-cadherin, VEGR1,2, and 3), CD99, and EMA, but were negative for S100, CK (AE1/AE3), CK20, polyomavirus, and myogenic (desmin and myogenin) and melanocyte markers (melan-A and HMB45). Ki67 immunos…