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PubMed1996

Merkel cell cancer: is prophylactic lymph node dissection indicated?

Our objective was to determine prognostic factors and the role of prophylactic lymph node dissection in Merkel cell cancer. A retrospective chart review of 15 patients from Loma Linda University Medical Center, Loma Linda, and Kaiser Permanente, Fontana, was used. The most important predictor of survival was presence of lymph node metastasis (P = 0.03). Lymph node metastasis was the first sign of recurrence in 60 per cent of patients and preceded distant metastasis. Age at presentation, tumor size, and location had no influence on survival. Gross presurgical determination of tumor extent was misleading. Microscopically positive margins necessitated reexcision in 60 per cent of patients. Local recurrence occurred in 27 per cent of patients. Recurrence at lymph node basins was lower in patients with elective lymph node dissection (0%) compared with therapeutic node dissection (57%)(P < 0.05). Incidence of micrometastases in patients undergoing prophylactic lymph node dissection was 100 per cent. No difference in survival was seen between prophylactic and therapeutic node dissection. Because Merkel cell cancer spreads in a "cascade" fashion, elective node dissection may provide a chance for a cure. Elective node dissection provides better locoregional control compared with therapeutic node dissection and helps to determine prognosis.

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PubMed1985

Serum neuron-specific enolase in metastatic Merkel cell tumors.

Three patients with widely disseminated Merkel cell tumors of the skin are presented. In all three cases, neuron-specific enolase (NSE) was demonstrated in neoplastic tissue by immunohistochemical staining, and serum NSE levels were also elevated in all three patients. Serum NSE may prove to be a useful tumor marker in this and other malignancies of neuroendocrine origin.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1992

The distribution of Merkel cells in human fetal and adult skin.

Merkel cells (MCs) have been a subject of investigation in human and animal studies for over a century, but their origin, function(s), and exact distribution in human skin remain largely unknown. The objectives of the present study were to quantify these cutaneous neuroendocrine cells in fetal and adult human skin, using an immunohistochemical marker (neuron-specific enolase) and morphometric methods. Our results indicate that, in postnatal life, MC are sparsely distributed along the undersurface of epidermal and occasionally adnexal epithelium in an approximate range of 0.1-1.0 MCs per centimeter of basal zone. They are most numerous on volar skin and least on genital skin, and on the face they have a primarily perifollicular orientation. Fetal samples have shown that MCs appear between the 15th and 18th week of gestation and are most abundant on volar skin. They appear to arise within the epidermis, and are initially numerous and later diminish with increasing gestational age. Their predominance in intrauterine life suggests a functional role in growth and development.

Adult↗
PubMed1982

Trabecular or Merkel-cell carcinoma of the skin.

The Merkel-cell tumor (trabecular carcinoma) is an unusual skin appendage malignancy that often recurs locally after initial excision. Occasional regional node metastasis occurs with the larger lesions. This report details our experience with six patients who developed this lesion. Illustrated is a spectrum of malignancy from a locally limited tumor to ones that led to death of the patients. Recognition of this rare tumor is important to ensure proper local treatment with close follow-up observation of the patient.

Adenocarcinoma↗
PubMed1986

Merkel cells do not express bullous pemphigoid antigen.

Merkel cells (MC) are epithelial cells expressing cytokeratin-type intermediate filaments. They often are localized within the basal cell layer of the epidermis. Since basal cell layer keratinocytes synthetize basal membrane components, it was of interest to investigate whether or not MC could also do so. We used both double-labeling immunofluorescence and immune electron microscopy techniques with a panel of antibodies allowing the identification of MC as well as the staining of basal membrane zone components (including bullous pemphigoid antigen, laminin, type IV collagen and epidermolysis bullosa antigen). A specific loss of BP antigen expression was observed below all MC directly in contact with BMZ. This suggests that, although being an epithelial cell and in contrast to basal keratinocytes, MC does not secrete BP antigens.

Animals↗
PubMed1989

Detection of calcium binding sites in Merkel cell granules of fetal rat skin.

We utilized a cytochemical calcium-staining technique to detect a potential calcium binding site within Merkel cell granules. Calcium has been shown to be essential for exocytotic release in various neuroendocrine cells and recent investigations strongly support the hypothesis that Merkel cells should be considered to be neuroendocrine cells which release their specific granules as a part of their physiological functions. After the addition of 50 mM CaCl2 to glutaraldehyde as the primary fixative, buffer, and OsO4 as a postfixative, electron-dense particles with a characteristic staining pattern were found within many MCGs. Successful removal of these particles after incubation of sections in a solution containing EDTA indicated that these particles were formed by calcium deposits. The occurrence of calcium binding structures within MCGs may imply that they play a role in the process of granule release and/or granule maturation.

Animals↗
PubMed1998

Merkel cell differentiation in trichoblastoma.

Four cases of trichoblastoma rich in Merkel cells (MCs) are reported. They occurred in two men and two women, with ages ranging from 58 to 76 years (mean 67.5 years). MCs were detected immunohistochemically with antibodies to keratin 20, chromogranin A and neuron-specific enolase (NSE). In an attempt at better definition of the nature and role of MCs in trichoblastoma, the distribution of MCs in normal adult and fetal skins obtained at autopsy was studied. In addition, ten cases of sebaceous naevus of Jadassohn (NSJ) were evaluated along similar lines. MCs made up 2-20% of the tumour cells in trichoblastomas; they were present in normal fetal skin and were rare in normal adult skin. All but one of the cases of NSJ showed numerous positive cells in the epidermal component of the lesion with all three antibodies. Six basal cell carcinomas and one syringocystadenoma papilliferum associated with NSJ were negative with keratin 20, chromogranin A and NSE antibodies, whereas a minute trichoblastoma arising against the same background was positive for these markers. Hair follicle cell tumours may recapitulate the skin embryogenesis, as numerous MCs are present in fetal follicles, but only occasional such cells are seen in adult skin.

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PubMed1997

Two cases of Merkel cell carcinoma cured by intratumor injection of natural human tumor necrosis factor.

Two patients were treated with intratumor injection of natural human tumor necrosis factor for recurrent or primary Merkel cell carcinoma. In both patients, local chemotherapy achieved complete tumor regression without causing ulceration or scarring. These results suggest that intratumor injection of natural human tumor necrosis factor may be very effective for the treatment of Merkel cell carcinoma.

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PubMed1992

Merkel cell carcinoma and iodine-131 metaiodobenzylguanidine scan.

Two cases of Merkel cell carcinoma, a neuroendocrine neoplasia of the skin, investigated with iodine-131 metaiodobenzylguanidine (131I-mIBG) scintigraphy, are reported. Uptake in the tumor was evident only in 1 case. The possible diagnostic and therapeutic role of 131I-mIBG in patients with this rare neoplasm is discussed.

3-Iodobenzylguanidine↗
PubMed2001

Merkel cell carcinoma arising in the head and neck: optimizing therapy.

Merkel cell carcinoma (MCC) is a rare and aggressive neuroendocrine dermal neoplasm. Because of the limited number of cases described in the literature (approximately 600 to date), statistically significant data regarding treatment are difficult to obtain. The majority of MCC cases affect the head and neck and are thought to be caused by the actinic damage associated with sun exposure. This study evaluates cases of head and neck MCC at Naval Medical Center San Diego (NMCSD) and compares the treatment regimens and outcomes from multiple institutions. This study is a retrospective outcomes analysis of all cases of head and neck MCC seen at NMCSD, between January 1, 1988 and June 30, 1998. The records of the NMCSD Tumor Registry were searched for patients with that diagnosis, and supplemental information was retrieved from the Radiation Oncology and Head & Neck Surgery Clinic charts. Eight of nine patients in this study were treated with either wide-local excision or Mohs microsurgery. The surgical margins were free of disease in all eight patients. One patient presented with distant metastatic disease, and two others were subsequently found to have nodal involvement. Subsequent therapy varied among the patients. Survey of the available literature revealed inconsistency in terms of which treatment regimens are optimal. Tumor resections are recommended by most groups to include a 2-cm to 3-cm tumor-free margin around the primary lesion when possible, but this is often difficult to achieve in the head and neck. Data, which do not reach statistical significance, suggest improved outcomes with tumor-free margins. Treatment of the regional draining lymph nodes is also recommended in most series. Prophylactic lymph node dissection or radiation therapy to the nodal chain may decrease local recurrence but does not consistently affect overall survival. Adjuvant chemotherapy is advocated by most groups in the treatment of metastatic disease because MCC is pathologically similar to small-cell lung carcinoma. However, no chemotherapy protocol has been shown to improve survival. Head and neck MCC is a rare and aggressive dermal tumor of neuroendocrine origin that requires multimodality therapy, including surgery, radiation therapy, and possibly adjuvant chemotherapy. Multiinstitutional studies are crucial to obtain sufficiently large populations to investigate and optimize therapy in this disease.

Aged↗
PubMed1998

Fine-needle aspiration of Merkel cell carcinoma of the skin with cytomorphology and immunocytochemical correlation.

Merkel cell carcinoma (MCC) of the skin is a rare, primary malignant skin neoplasm which can present as a cutaneous nodule. These neoplasms are seen primarily in the elderly and located in the head and neck area or extremities. Twenty-nine aspirates from primary and metastatic lesions obtained by percutaneous fine-needle aspiration in 19 patients have been studied. The cytomorphologic features, clinical information, and immunocytochemical (ICC) findings are detailed. Aspirate smears demonstrated small-to-intermediate-sized cells with a loosely cohesive pattern. Nuclei were round with finely granular chromatin and multiple, small nucleoli. Cells possessed a thin rim of cytoplasm, and infrequent pseudorosette formations were noted in cell groups. ICC results were universally positive for cytokeratin, which showed a paranuclear "dot-like" pattern. Neuron-specific enolase, epithelial membrane antigen, and S-100 protein were positive in varying degrees. Leukocyte common antigen was universally negative. The diagnosis of MCC of the skin by FNA can be made by applying cytologic features in addition to ancillary studies and clinical information.

Adult↗
PubMed1994

Merkel cell carcinoma: a clinico-pathological report of 3 cases.

Merkel cell carcinomas are rare. The head and neck are the commonest sites of presentation. They are slightly more common in females and are frequently misdiagnosed. This tumour has had little coverage in the surgical journals which accounts for the low index of suspicion. Three cases, which were successfully treated surgically, are presented in order to increase awareness. It is a diagnosis that one should have in mind when examining an atypical skin lesion.

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PubMed1984

Merkel cell carcinoma of the vulva.

The authors describe the clinical and histologic findings in a case of Merkel cell carcinoma of the vulva, which was associated with squamous cell carcinoma in situ and lichen sclerosus. Electron microscopy of the tumor revealed membrane-bound granules. At postmortem examination, metastases from this primary skin tumor were found in the pelvic lymph nodes, in paraortic lymph nodes, in the liver, and in vertebral bodies. The case is unusual because Merkel cell tumors are usually found on the face or the extremities and seldom metastasize widely.

Aged↗
PubMed1999

[Merkel cell carcinoma. Utility of scintigraphy with 111In-DTPA-pentetreotide].

Merkel cell carcinoma (MCC) is an unusual malignant primary skin tumor, having a high incidence of local recurrent, and regional and distant metastasis. Due to its capacity to express somatostatin receptors, it can be detected in vivo with 111In-pentetreotide scintigraphy (Ostreoscan). We present a case of a MCC whose scintigraphy revealed regional metastases of a primary frontal cutaneous tumor that had been removed previously. The results verified a good correlation with clinical, radiological an histopathological findings.

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PubMed1991

Loss of allelic heterozygosity on distal chromosome 1p in Merkel cell carcinoma. A marker of neural crest origins?

The location of genes involved in tumor evolution has been inferred from experiments in which loss of constitutional heterozygosity has been detected in tumor DNA at high frequency in specific chromosome regions. For example, cytogenetic and molecular abnormalities on chromosome 1p have been reported in tumors such as malignant melanoma and neuroblastoma which arise in cells derived from embryonic neural crest tissue. To extend these observations, we have examined tumor DNA from three cases of Merkel cell carcinoma for evidence of loss of constitutional heterozygosity on the short arm of chromosome 1. In all three cases, heterozygous allelic deletions of varying extent on distal chromosome 1p were detected in tumor DNA. Comparisons with neural crest tumors suggest that loss of heterozygosity on distal chromosome 1p in Merkel cell tumors may be a marker of neural crest origin.

Alleles↗
PubMed2000

[Merkel cell carcinoma in otolaryngology].

The authors presented two cases of Merkel cell carcinoma, a rare malignant neoplasm of neuroendocrine origin located in parabasal layer of epithelium. The first described case was 67 year old woman, after resection of primary tumor of eyelid, with metastases in lymph nodes of parotid gland. The second case was 44 year old woman with the primary tumor in retroauricular region. The patient underwent radiotherapy 23 years earlier due to malignant lymphoma. Basing on the available literature the authors discussed clinical and histological features of this malignancy, they stressed the important role of immunohistochemical tests in the diagnosis.

Adult↗
PubMed2004

Merkel cell carcinoma: a case report with treatment summary and updates.

Merkel cell carcinoma (MCC) is a rare primary cutaneous neoplasm known for its propensity to develop early regional and distant metastasis. Fewer than 400 cases occur annually in the United States. MCC ranks as the most deadly of cutaneous malignancies, with a fatality rate of approximately 25%. Because of its aggressive nature, MCC is often resistant to surgery, radiation, and chemotherapy regimens. Standardized treatment patterns have not been established, and difficulty arises finding appropriate treatment for the elderly, who comprise the majority of patients with MCC.

Aged↗