Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Merkel Cells”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 595 records · Page 33Linked to original sources
PubMed1989

[Primary palpebral localization of a trabecular Merkel cell carcinoma (1 case)].

We report one case of Merkel cell carcinoma. They commonly arise on the eyelids of elderly patients. Others localisations are on the skin of the pelvis. Clinical aspects, histological study, associating morphological aspect, ultra-structural and immuno-histo-chemical studies are characteristics enough to differentiate this tumor others tumors of the skin like cutaneous malignant lymphoma. The origin of this tumor is still discussed, but sure neuro-endocrinal. Possibility of visceral metastases on a small number of cases (6 to 8%) must be consider when treated. Total surgical ablation should be obtained.

Adenocarcinoma↗
PubMed2006

[Merkel cell carcinoma in a patient with chronic lymphocytic leukemia].

Merkel cell carcinoma (MCC) is an infrequent neuroendocrine tumor of the skin with a high potential for local recurrence, lymphatic dissemination and distant dissemination. We present a case of MCC in a male patient with chronic lymphocytic leukemia (CLL). The immunosuppression induced by the leukemia or by the chemotherapy could play a pathogenic role in the association of these diseases. Positron emission tomography (PET) was a useful staging technique in this patient, and made the differential diagnosis of the lymph node involvement from MMC and CLL possible.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1988

Merkel cell carcinoma arising in the oral mucosa.

This is the first reported case of a Merkel cell carcinoma arising in the oral mucosa. The tumor occurred in a 53-year-old white man, and it originated in the right mucobuccal fold. The Merkel cell origin was confirmed by electron microscopic and immunohistochemical studies.

Adenocarcinoma↗
PubMed1995

Lymphoscintigraphy in a case of Merkel cell tumor.

The authors report a rare case of Merkel cell tumor with the findings of lymphoscintigraphy. The study was performed to delineate anatomic lymphatic drainage from the primary skin lesion to help surgeons to decide which lymphatic basin(s) should have elective lymph node dissection. The lesion was situated in the midline on the back and at the border zone in the lumbar area from which it could drain superiorly to the axillary lymph nodes(s), inferiorly to the inguinal node(s), or to both directions. Because of this location, prediction of the lymphatic drainage by applying conventional anatomical knowledge from the lymphatic atlas was not easy. However, the lymphoscintigraphy was very helpful and subsequent pathologic examination of surgical specimens confirmed the interpretation of the lymphoscintigraphy.

Axilla↗
PubMed1999

Brain metastasis of Merkel cell carcinoma. Case report and review of the literature.

Merkel cell carcinoma (MCC) is a rare primary cutaneous neuroendocrine tumor that is locally aggressive and has potential for metastatic spread. However, brain metastases are rare, and therapy for such tumors has never reported. The authors present a 48-year-old woman with MCC of the left elbow and a right cerebellar metastasis. After the right cerebellar mass was totally resected, radiation treatment and chemotherapy were performed. Eight cases of brain metastasis have been reported in the literature, but only 5 have been presented in sufficient detail for analysis. Therapy for brain metastases has always been palliative whole-brain irradiation and chemotherapy except for our patient, who underwent total removal of the tumor and survived for 11 months without neurological deficit. Except in the case of 1 with a particularly radiosensitive MCC, the patients with brain metastases died within 9 months after detection of the brain lesions. If possible, aggressive excision of brain metastases as well as of the primary lesion should be done.

Carcinoma, Merkel Cell↗
PubMed1995

Cutaneous neuroendocrine (Merkel cell) carcinoma. A report of 35 cases.

Cutaneous neuroendocrine (Merkel cell) cancer (CNEC) is a rare skin tumor with a highly malignant nature. Initial treatment of this tumor has often been limited to a local excision. The medical records of 35 patients diagnosed with CNEC and treated at Southern California Kaiser Permanente Medical Group or UCLA Medical Center between 1980 and 1991 were reviewed. There were 26 male and 9 female patients were enrolled in this study. Minimum follow-up from date of diagnosis was 18 months, mean follow-up was 40 months; 25 patients presented with local disease (stage I) and 10 patients presented with regional disease (involved nodes, stage II). Patients who were treated initially with local therapy alone had a 65% recurrence rate and a 29% mortality rate, while those patients treated locoregionally at presentation had only a 27% recurrence rate and 14% mortality rate, although the majority presented with more advanced disease. Due to the high incidence of lymph node failure and death in patients treated locally versus locoregionally at presentation, we feel that planned locoregional treatment is indicated for all patients presenting with CNEC, regardless of stage.

Adult↗
PubMed1996

Merkel cell carcinoma of the skin: imaging and clinical features in 93 cases.

Clinical, pathological and imaging data for 93 patients with Merkel cell carcinoma were reviewed. Median survival duration from the date of diagnosis was estimated using the Kaplan-Meier product-limit method. Survival durations of patients with no metastastic disease, with regional lymph node metastasis only and with distant metastases were compared using the Cox-Mantel log-rank test. The median age for patients with Merkel cell carcinoma was 70 years (range 35-91 years). The tumour occurred in 71 men and 22 women. The most common primary site was the head and neck region (64 patients), followed by the extremities (21 patients) and the trunk (10 patients). Median survival duration for the whole group was 33 months (range 2-140 months). Imaging studies of the primary sites were available for 10 patients and of metastatic sites for seven patients. Sonograms of the primary skin lesions showed single or multicentric hypoechoic nodules arising from the dermis and growing into the subcutaneous tissues. CT scans showed single or multiple minimally enhancing soft tissue nodules, in two instances associated with lytic bone erosion. The metastatic lesions were moderately hypoechoic on sonography and target-shaped with or without ring-enhancement on CT. Imaging studies have a limited role in diagnosis of the clinically evident primary skin lesions, but may be helpful in the assessment of the depth of the invasion and are crucial in the evaluation of regional and distant metastatic disease. If regional adenopathy is found then CT of the chest, abdomen and pelvis may be in order.

Adult↗
PubMed2003

Merkel cell carcinoma: a clinicopathological study of 34 patients.

BACKGROUND: Merkel cell carcinoma (MCC) is a rare cutaneous malignant tumour. Its natural course is fast progression of the primary tumour and rapid regional metastasis. METHODS: The pathological archives of Helsinki University Hospital and Vaasa Central Hospital were reviewed from 1987 to 2001. Specimens were re-evaluated by two pathologists and size was measured from primary tumours. Multivariate analysis was performed for age, sex, primary tumour size, and method of initial surgery, development of metastatic disease and development of local recurrence. Overall survival (OS) was calculated by the Kaplan-Meier method. RESULTS: Of 34 patients, 12 male and 22 female patients, are reported. Their median age was 76.4 years. Half of the primaries were located in the head and neck region. All patients were treated surgically. The mean OS was 2.7 years by the Kaplan-Meier method. The 2-year survival rate was 65% and 5-year rate was 50%. The mean OS for tumour size >2 cm was 1.7 years and for tumour size 2 cm) and metastatic dissemination. A favourable prognosis seemed to correlate to more aggressive surgical management as use of primary excision with split skin graft or reconstruction with a local flap. CONCLUSION: MCC affects the elderly patients. In this study, female patients predominated. Primary tumour size >2 cm predicts poorer outcome of the disease. A wide surgical excision is recommended for the primary treatment of MCC.

Aged↗
PubMed2004

Merkel cell carcinoma: a clinicopathologic study with prognostic implications.

BACKGROUND: Merkel cell carcinoma (MCC) is a frequently aggressive neuroendocrine malignancy of the skin that presents in sun-exposed areas on elderly patients. Although originally described over 30 years ago, many aspects of MCC remain to be defined. Of particular importance is the need to identify prognostic factors capable of predicting the biological behavior of these tumors. Knowledge of these factors may help in determining which patients require more aggressive treatment regimens. In this study, we examined 25 cases of MCC with an attempt to identify clinical, histopathological, or immunohistochemical features capable of predicting disease outcome. METHODS: Features that we evaluated in each case included age, gender, race, tumor location, tumor size, depth of invasion, growth pattern, lymphocytic infiltration, mitotic activity, ulceration, necrosis, vascular invasion, and perineural invasion. In addition, we examined neural cell adhesion molecule and cytokeratin-20 expression using immunohistochemical methods. RESULTS: We found that most patients were males (84%) with an average age of 74 years. The tumors were located on the head and neck (68%) and upper extremities (32%). Overall, 64% of the patients developed metastatic disease to regional lymph nodes or distant sites (average follow-up time of 21 months). Local recurrence was also common, occurring in 29% of the patients. The overall 1- and 2-year survival rates were 80 and 53%, respectively. Histopathological examination revealed tumors with an average size of 7.2 mm. Common features included invasion into the subcutaneous adipose tissue, solid growth pattern, tumor necrosis, and vascular and perineural invasion. Findings that had a statistically significant correlation with poor outcome included tumor size > or =5 mm (p = 0.047), invasion into the subcutaneous adipose tissue (p = 0.005), diffuse growth pattern (p = 0.040), and heavy lymphocytic infiltration (p = 0.017). The remaining findings, including the immunohistochemical results, did not correlate with disease outcome. Using logistic regression models, we show that depth of invasion and degree of lymphocytic infiltration are strong predictors of disease outcome. CONCLUSIONS: The current controversies regarding the treatment of early-stage MCC (i.e., localized disease) underscore the importance of identifying clinicopathological features capable of predicting tumor behavior. In this study, we have identified several prognostic features in MCC. Perhaps, these features may prove useful in identifying patients who require more aggressive treatment regimens.

Aged↗
PubMed2006

Merkel cell carcinoma: experience of 14 cases and literature review.

Merkel cell carcinoma is an aggressive skin cancer, with a significant incidence of locoregional lymphnode involvement, which requires timely diagnosis, adequate staging and aggressive therapy based essentially on surgical procedures. The aim of this study is to report our experience and to compare our results with literature findings, in order to discuss the role of the procedures adopted and their influence on prognosis. From July 1995 to April 2005, 14 patients were treated and followed-up for MCC in the National Cancer Institute of Naples. Tumor location was: buttocks (43%), extremities (36%) head (7%), unknown (14%). There were 7 Stage I, 5 Stage II and 2 Stage III patients. Surgical treatment consisted in wide excision (WE) in Stage I cases, WE and regional lymphadenectomy followed by radio- or chemo-therapy in Stage II and combined surgical and pre- and post-operative medical treatments in Stage III. Overall disease specific survival rate was 64% (median follow up 44 months). Recurrence occurred in 86% of Stage I and 20% of Stage II patients and involved, in 83.3% of Stage I patients, the lymph nodal draining basin. The treatment of recurrence implied surgery and radio or radiochemotherapy. Overall survival rate of recurrent patients was 57% (median follow-up 37.2 months). Due to the particular lymphotrophism of MCC, major care should be set on investigation and treatment of tumor lymph nodal draining basin. As long as the disease remains surgically manageable the prognosis for patients with MCC is favourable. The role of radio and chemotherapy is not yet assessed.

Adult↗
PubMed1999

Surgical management of Merkel cell carcinoma.

OBJECTIVES: To characterize the natural history of Merkel cell carcinoma (MCC) and to analyze the influence of patient, tumor, and treatment-related variables on survival and recurrence. SUMMARY BACKGROUND DATA: Approximately 425 cases of MCC have been described in the literature. This study represents the largest experience reported. METHODS: A review was performed of patients who had been treated at Memorial Sloan-Kettering Cancer Center for MCC between 1969 and 1996. Follow-up data were available for 102 of the 109 (94%) patients identified. RESULTS: The overall 5-year disease-specific survival rate was 74%. The median follow-up was 35 months. For all patients, the only independent predictor of survival was the tumor stage at presentation. For patients with stage I disease, the tumor size at presentation was also an independent predictor of survival. Recurrence of disease occurred in 55 patients (55%), and the most common site of first recurrence was within the draining lymph nodes (n = 35). Elective lymph node dissection was the only parameter independently predictive of improved relapse-free survival. The overall disease-specific survival rate after recurrence was 62%. Predictors of improved disease-specific survival after recurrence included nodal as compared to local or distant recurrence, the ability to render the patient free of disease after recurrence, and a disease-free interval of >8 months. CONCLUSION: The prognosis for patients with MCC is favorable, and even after recurrence the majority of patients experience long-term survival. Incorporation of size into the staging system more accurately predicts survival in patients with stage I disease. Although elective lymph node dissection decreased the rate of recurrence, it was not associated with improved overall survival.

Adult↗
PubMedDate not supplied

Merkel cell carcinoma of the eyelid: a case report.

A 22-year-old woman who presented with a tumour of the upper eyelid with clinical, histological, immunohistochemical and ultrastructural features of a Merkel cell carcinoma is reported. This is a unique case of Merkel cell carcinoma in such a young patient. This neuroendocrine tumour is typically found in the elderly. It can grow rapidly, has the potential for local recurrence and early metastatic spread. The authors recommend wide resection of the primary site, which proved effective in this case.

Adult↗
PubMedDate not supplied

Merkel cell carcinoma of the external auditory canal invading the intracranial compartment.

PURPOSE: To report an unusual case of an intracranial extension of Merkel cell carcinoma originating in the external ear canal and causing neurological deficits. CASE REPORT: An 86-year-old woman, with a 16-month history of an external auditory canal mass, presented with hemiparesis, facial paralysis, and obtundation. Radiographic images showed an intracranial mass extending into the petrous bone. METHOD: The patient had a craniotomy for intracranial tumor resection with concurrent mastoidectomy for facial nerve decompression and obtundation and hemiparesis were resolved. Residual tumor was subsequently treated with adjuvant radiation therapy, and facial nerve function consequently improved. CONCLUSION: Merkel cell tumors rarely invade the intracranial compartments. Residual tumor and neurological deficits may respond to adjuvant radiation therapy.

Aged↗
PubMed2001

Merkel cell carcinoma of the skin and mucosa: report of 12 cutaneous cases with 2 cases arising from the nasal mucosa.

BACKGROUND: Merkel cell carcinoma (MCC) is an uncommon skin tumor that most frequently arises on sun-exposed facial sites. It rarely occurs on mucous membranes of the head region. The primary MCC is usually treated by wide excision followed by radiation to the primary site and regional lymph nodes. Using traditional surgery the local recurrence rate ranges from 20 to 50%. In our clinic, Mohs surgery is used to excise the primary MCC completely, followed by radiation. Here we present our treatment experiences and outcomes. OBJECTIVE: To document our experience of MCC treated by Mohs surgery. We present our series of 12 cases of MCC, 2 cases of which arose from mucosal sites of the nasal cavity. METHODS: We reviewed 12 cases of MCC from the Mohs clinic database. We also reviewed the literature for cutaneous and mucosal MCC. RESULTS: There were 12 cases of MCC: 10 cutaneous and 2 mucous. The site distribution of cutaneous MCC was eight on the head, one on the neck, and one on the groin. Of these, nine were treated by Mohs excision. Two patients developed local recurrence following Mohs treatment. The local recurrence rate was 22% (2 of 9). The sites of mucosal MCC were the nasal septum and nasopharynx. One case had a history of previous radiation and developed an MCC 40 years later. This case also demonstrated epidermotropic spread of Merkel cells to the overlying mucous epithelium. This patient required extensive intranasal and cranial surgery to remove the tumor. Both patients with mucosal MCCs died of their disease. The overall mucocutaneous survival of MCC at 1 year was 80% and at 2 years was 50%. CONCLUSION: In our series, local control of the primary MCC was achieved in 70% of patients (7 of 10) using combined Mohs excision and radiation. Two recurrences had primary tumors larger than 3.5 cm in diameter, while the other case was nonresectable by Mohs surgery. Tumor size appeared to determine the degree of local control. When the postoperative Mohs defect was less than 3.0 cm in diameter, local and regional control appeared to be more favorable. When the primary facial MCC is relatively small, removal by Mohs surgery followed by radiation was effective, therapeutic, and less disfiguring. Mucosal MCC is rare and may occur as a long-term sequelae after radiation therapy to the skin.

Aged↗
PubMed1986

A neuroendocrine (Merkel) cell carcinoma with coexisting intraepidermal squamous cell carcinoma of the skin. Its growth accelerated by an extrinsic factor.

A case of neuroendocrine (Merkel) cell carcinoma with coexisting intraepidermal squamous cell carcinoma of the skin was studied histologically, immunohistochemically and ultrastructurally as well as with tissue-culture and transplantation into nude mice. The primary tumor found in the lower leg of a 68-year-old Japanese man had remained thumb-sized for five years and, after contusion, had begun to enlarge rapidly up to 5 cm in size during one month. The patient died of metastatic neuroendocrine cell carcinoma nine months after excision of the primary tumor. Histologically the primary tumor was composed of neuroendocrine cell carcinoma extending down to subcutaneous adipose tissue and a small amount of intraepidermal squamous cell carcinoma, not associated with a wide range of necrosis, hemorrhage, granulation tissue or fibrosis. The tumor cells of the former were diffusely positive for neuron-specific enolase. They contained a few secretory granules, 100 nm in diameter. The tumor cells both cultured in media and transplanted into nude mice died two months later. The present case is the first report of Merkel cell carcinoma in which the growth accelerated by an extrinsic factor was proved. Histogenesis of neuroendocrine cell carcinoma with coexisting squamous cell carcinoma is also discussed.

Adenocarcinoma↗
PubMed1986

The use of antikeratin antibodies in the immunohistochemical distinction between neuroendocrine (Merkel cell) carcinoma of the skin, lymphoma, and oat cell carcinoma.

Paraffin sections of formalin-fixed tumor samples from 26 patients with neuroendocrine (Merkel cell) carcinoma of the skin (NECS) were studied immunohistochemically with three monoclonal antibodies to low molecular weight keratin (MAB-K) and with antibodies to leukocyte common antigen (LCA), neurofilament (NF), neuron-specific enolase (NSE), S100 protein (S100), and chromogranin (CGN), to investigate the relative diagnostic value of these antibodies. Samples from 20 lymphomas, 10 non-oat cell undifferentiated carcinomas, 10 oat cell carcinomas, and 10 melanomas served as controls. Keratin was found in 25 of the 26 NECS and in all undifferentiated and oat cell carcinomas. A ball-like immunostaining for keratins, resembling an inclusion body was seen only in cases of NECS and some carcinoids. Neurofilament, NSE, and CGN were expressed by fewer NECS than was keratin and all NECS were negative for LCA and S100. None of the lymphomas and melanomas contained detectable keratin, NF, NSE, or CGN. Only the lymphomas stained with LCA. Only the melanomas were S100-positive. It is concluded that keratin is the most useful single discriminating marker in the separation of neuroendocrine (Merkel cell) carcinoma of the skin from lymphoma, melanoma and, when the characteristic inclusion-like pattern is seen, from metastatic oat cell carcinoma.

Adult↗
PubMed1994

Probable mechanisms of loss of Merkel cells in completely depigmented skin of stable vitiligo.

Vitiligo is frequently associated with segmental involvement. It spares paralyzed limbs in transverse myelitis. There is spontaneous repigmentation of vitiligo lesional skin (VL) in diabetic neuropathy. Increased neuropeptide in VL and adjacent normal skin of vitiligo (ANS) along with thickened nerve fibers showing ultrastructural abnormalities all indicate a neural pathogenesis (1). Loss of Merkel cells has been observed in early vitiligo lesional skin (2). Recently, catecholamines have been found to play a major role in initiating the cascade of events leading to loss of melanocytes (1, 3, 4). To investigate the presence of Merkel cells in the completely depigmented skin of stable vitiligo (SV), a study was undertaken using TROMA 1, a monoclonal antibody specific for adult Merkel cells. No TROMA 1-positive cells were observed in SV, whereas normal numbers of these cells were seen in ANS. This new finding further supports the hypothesis of neural involvement in vitiligo.

Adolescent↗
PubMed1988

Chemotherapy for metastatic Merkel cell carcinoma. Review of the M.D. Anderson Hospital's experience.

Thirteen patients with regional or distant metastases from Merkel cell carcinoma were treated with combination chemotherapy. Three patients had a complete response to therapy. In two patients with nodal disease the duration of response was 10+ and 4+ years. In addition, three patients had a partial response, and six patients had minor responses. Chemotherapy using a combination of drugs that are active against small cell carcinoma of the lung is recommended in the treatment of unresectable disease in patients with Merkel cell carcinoma; it may produce prolonged responses. While tumor regressions as a result of chemotherapy were often dramatic, once the disease progressed, the course of the disease often moved rapidly downhill and proved to be fatal.

Adult↗