1/18. Diagnostic relevance of chromosomal in-situ hybridization in Merkel cell carcinoma: targeted interphase cytogenetic tumour analyses.AIMS: To resolve the conflicting diagnoses of five pathologists (which included well-differentiated neuroendocrine carcinoma, malignant carcinoid, undifferentiated small-cell carcinoma, primitive neuroectodermal tumour, metastases of small-cell lung carcinoma (SCLC) and Merkel cell carcinoma (MCC)), and tumour-free lungs after necropsy, we investigated an alarmingly metastasizing MCC in a 32-year-old Caucasian man using chromosomal in-situ hybridization (CISH). Differences in incidence and course in males and females also prompted targeted analyses for chromosomes X and Y. The lesion was also analysed for p53 gene mutations. methods AND RESULTS: paraffin sections of the thorax, buccal lymph nodes and scalp tumours were stained with haematoxylin and eosin. immunohistochemistry was performed with antibodies against pancytokeratin, keratin 20, neuron-specific enolase (NSE), chromogranin, neurofilaments and vimentin, among others. Sections (5-6 microm) of the tumours were analysed with alpha-satellite probes for chromosomes 1, 6, 7, 11, 12, 17, 18, X and Y using CrSH; and exons 5-9 of the p53 gene were examined by polymerase chain reaction and single strand conformation polymorphism (PCR-SSCP) methods. Although positive for pancytokeratin, keratin 20, chromogranin, NSE, synaptophysin and vimentin, the similarity in antigen profiles expressed by SCLC and MCC prevented a definitive tumour diagnosis. Chromosomal in-situ hybridization, however, revealed trisomies 1 and 11, two frequent aberrations in MCC, and trisomy 18. Moreover, 71% of the tumour cells had two to three copies of X, whereas 98% of the cell nuclei in the hair follicles and normal epidermis (purported Merkel cell origins) displayed one x chromosome. No mutations were detected in the five exons of the p53 gene examined. CONCLUSIONS: Had CISH been performed earlier, treatment may have been tailored specifically to suit MCC, since MCC and SCLC have different therapeutic strategies. Finally, chromosome X may be of prognostic relevance in MCC, which apparently predominates in females and yet shows poorer prognosis in males, and hence be worthy of further investigation.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
2/18. Intraepidermal Merkel cell carcinoma with no dermal involvement.Cutaneous Merkel cell carcinoma (MCC) typically involves the dermis. Less than 10% of MCC have epidermal involvement. Only one MCC confined exclusively to the epidermis has been previously reported but was not recognized until the lesion recurred with typical MCC in the dermis. We present a case of a wholly intraepidermal pagetoid MCC without dermal involvement in a 74-year-old man with a 2.0-cm solitary verrucous papule on the left index finger. The initial biopsy and complete excision specimens showed marked epidermal hyperplasia, focal prominent squamous cell atypia, and MCC with florid pagetoid spread through the epidermis. There was no evidence of tumor within the dermis. The pagetoid MCC tumor cells showed diffuse cytoplasmic staining with antibodies to cytokeratin 20, and negative staining for chromogranin, neurofilament, S-100, vimentin, HMB45, leukocyte common antigen, and CD3. The cell of origin of MCC is still debated. The existence of an entirely intraepidermal variant of MCC would lend support to the view that MCC is a neoplastic expression of merkel cells in at least some cases. Dermal-based MCC is a high-grade primary cutaneous neoplasm, but MCC confined exclusively to the epidermis may have a better prognosis.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
3/18. Merkel cell (neuroendocrine) carcinoma of the vulva. A case report with immunohistochemical and ultrastructural findings and review of the literature.A new case of primary Merkel cell carcinoma (MCC) of the vulva is reported and the literature reviewed for noting its clinical presentation, microscopic, immunohistochemical and ultrastructural features, as well as for establishing the role of immunohistochemistry in the ultimate diagnosis of this uncommon and aggressive tumor. The lesion occurred in a 79 year old patient. Histologically, the tumor was composed of intradermal small cells with high mitotic index and frequent apoptosis. The immunohistochemical study showed positivity for wide spectrum and low molecular weight cytokeratins, epithelial membrane antigen, neurofilaments, neuron specific enolase and chromogranin a. Electron microscopy revealed intermediate filaments in a typical globular paranuclear arrangement. The coexpression of cytokeratins (including cytokeratin 20) and neurofilaments, both in typical globular paranuclear arrangement, made possible the diagnosis of MCC, differentiating it from other malignant small cell tumors such as neuroendocrine metastatic carcinoma.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
4/18. Anti-Hu antibodies in Merkel cell carcinoma.Anti-Hu antibody is an antineuronal autoantibody found in a subset of patients with paraneoplastic neurological disease. The antibody was first associated with small cell carcinoma of the lung and is most often used as a marker for this neoplasm in patients presenting with suspected paraneoplastic syndromes. Here we report a patient with a multifaceted neurological disorder in the setting of Merkel cell carcinoma. The patient's serum contained antibodies against the Hu antigen, and the expression of the Hu antigen was demonstrated in the patient's tumor.- - - - - - - - - - ranking = 2keywords = antigen (Clic here for more details about this article) |
5/18. Cutaneous undifferentiated small (Merkel) cell carcinoma, that developed synchronously with multiple actinic keratoses, squamous cell carcinomas and basal cell carcinoma.Merkel Cell carcinoma (MCC) is an uncommon undifferentiated neuroendocrine tumor, arising in skin mainly on sun-exposed areas. We present an unusual case of primary cutaneous undifferentiated small cell carcinoma that co-existed with six other lesions; 2 actinic keratoses, 3 squamous-cell carcinomas and a basal-cell carcinoma. HE stained sections revealed MCC located in the mid-dermis, co-existing with severe actinic keratosis. Immunohistochemically, the tumor cells reacted to cytokeratin 20, epithelial membrane antigen, chromogranin and neuron specific enolase. This is an unusual case of cutaneous MCC co-existing with six other different lesions. The concurrent development of MCC, squamous-cell and basal-cell carcinoma in the same patient indicates the pluripotent epidermal stem cell origin of these tumors. Further research is needed to enlighten the factors inducing this divergent differentiation.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
6/18. Primary neuroendocrine carcinoma of the vagina with Merkel cell carcinoma phenotype.We describe a case of primary neuroendocrine carcinoma arising from the anterior vaginal wall of a 67-year-old woman. Primary neuroendocrine carcinoma of the vagina is a rare entity with only 25 previously reported cases in the literature. In previous reports, these tumors have not been distinguished from primary neuroendocrine carcinoma of the skin (Merkel cell carcinoma). The tumor was composed of cells that showed neuroendocrine-type nuclear features with hyperchromasia, nuclear molding, occasional small nucleoli, and a chromatin pattern that was finely granular. The tumor cells were positive for cytokeratin 20 (CK20), neuron specific enolase, pancytokeratin, epithelial membrane antigen, and chromogranin a expression. Ki-67, a marker of proliferation, was also positive in>90% of cells. The tumor cells showed intense expression of Bcl-2 oncoprotein and mild to moderate expression of c-KIT. synaptophysin, neurofilament, CD45, CD56, CD10, S-100, HMB-45, cytokeratin 7, and thyroid transcription factor 1 were negative. This pattern of staining is consistent with a Merkel cell carcinoma. This is the first report of a primary neuroendocrine carcinoma of the vagina with a Merkel cell phenotype. Previous studies have not distinguished primary neuroendocrine carcinoma of the vagina from Merkel cell carcinoma of the skin. Positive expression of CK20 in primary small cell carcinoma of the vagina might represent a Merkel cell carcinoma subtype of this tumor.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
7/18. Merkel cell carcinoma -- a rarity in the urogenital tract.BACKGROUND: Merkel cell carcinoma -- a rare, aggressive cancer of the skin integument - is being increasingly diagnosed but represents an absolute rarity in the urogenital tract. CASE REPORT: We report on a 70-year-old man who was referred to us with suspected testicular cancer. The pathology report revealed a metastasized Merkel cell carcinoma. Fulminant disease progression under chemo-therapy (regimen as for small cell lung cancer) resulted in death 5 months later. CONCLUSION: The patient described is considered to be the first to develop testicular metastasis derived from Merkel cell carcinoma. Besides neuroendocrine and epithelial antigen tests, somatostatin receptor scintigraphy is a helpful diagnostic tool. New receptor-associated therapies may allow more effective and less toxic treatment modalities in the mostly elderly or immune deficient patients.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
8/18. Primary neuroendocrine carcinoma of the eyelid, immunohistochemical and ultrastructural study.Primary neuroendocrine carcinomas of the skin were recognized as distinctive neoplasms and clinicopathologic information on their location on the eyelids have been reported. The authors present one case of primary neuroendocrine carcinoma occurring on the right lower lid in a 73-year-old woman. The clinical history, light and electron microscopic findings as well the results of an immunohistochemical study are described. The ultrastructural study demonstrated the characteristic membrane-bound dense-core neurosecretory granules. Immunoreactivity for neuron-specific enolase, keratin filaments, epithelial membrane antigen and calcitonin were observed and are strongly suggestive of a neuroendocrine differentiation in a neoplasm of epithelial origin. Various hypothesis concerning the origin of this tumor are discussed on the basis of the immunohistochemical findings. The authors also provide a brief review of the literature.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
9/18. Giant neuroendocrine (Merkel cell) carcinoma of the skin.An 82-year-old woman had a dark red to purple tumor on the left buttock that had gradually enlarged during the last 5 years. Although routine histologic examination was not sufficient for diagnosis, neuroendocrine carcinoma was diagnosed by immunohistochemical and ultrastructural studies. Immunohistochemical-positive reactions to neurofilament, cytokeratin, neuron-specific enolase, and epithelial membrane antigen were noted. Electron microscopically, membrane-bound, dense core granules that yielded a positive uranaffin reaction and intermediate filaments in the perinuclear area were observed in the cytoplasm of most tumor cells. Desmosome-like structure between them was also found. Approximately 6 months after local excision, metastatic lesions developed in the regional lymph nodes and liver.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
10/18. Neuroendocrine carcinoma of the skin (Merkel cell carcinoma): immunocytochemical study of a case.The immunocytochemical phenotype was evaluated in a case of Merkel cell carcinoma of the skin. intermediate filaments, i.e. neurofilament, glial fibrillary acid protein, cytokeratins, keratin and panfilament as well as S-100 protein, calcitonin and epithelial membrane antigen were detected by immunoperoxidase methods. Nodular positivity for neurofilament was observed. The remaining intermediate filaments and other markers were negative. Thus the origin of Merkel cell carcinoma appears uncertain and this tumor probably has neuroendocrine activity.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
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