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 433 records · Page 24Linked to original sources
PubMed1995

Further insights into the natural history and management of primary cutaneous neuroendocrine (Merkel cell) carcinoma.

PURPOSE: Primary cutaneous neuroendocrine (Merkel cell) carcinoma is a rare neoplasm with aggressive behavior but potential for response to radiotherapy and chemotherapy. Optimal treatment regimens are evolving based on reports of case series and a growing understanding of the natural history. METHODS AND MATERIALS: A retrospective analysis of 34 cases treated at two Australian Institutions over 13 years is presented, focusing on clinical features and response to therapy. RESULTS: The aggressive nature of this neoplasm is confirmed by the local recurrence rate of 22% following surgical excision, the development of regional node metastases in 76%, and of distant metastases in 70%. Overall median survival was 24 months with 65% of patients succumbing to metastatic disease. An association with B cell malignancies and immunosuppressive therapy is noted, with these patients having a poorer outcome, and one spontaneous remission was observed. Radiation therapy produced responses in 21 of 30 measurable sites (11 complete, 10 partial), and in 11 sites irradiated prophylactically there was only one infield relapse (9%). Responses to chemotherapy were observed in 8 of 20 applications (40%), particularly carboplatin and etoposide given in the setting of regional node disease. CONCLUSION: In this poor prognosis tumor, further investigation of adjuvant radiotherapy and chemotherapy is warranted, as responsiveness of recurrent disease is confirmed. Immunological factors appear important in the natural history, and their manipulation may offer additional therapeutic options.

Adult↗
PubMed1993

The use of cyclophosphamide, methotrexate, and 5-fluorouracil in the treatment of Merkel cell carcinoma.

Five patients with advanced Merkel cell carcinoma (MCC) are described. Four patients with regional lymph node involvement and one with disseminated skin metastases were treated with systemic chemotherapy, including cyclophosphamide, methotrexate, and 5-fluorouracil (CMF). The patients received a median of six cycles of CMF (range: 2 to 6), and chemotherapy was well tolerated. Four complete and one partial response were noted. Three patients are alive and are disease-free at 5, 12, and 37 months from the onset of CMF chemotherapy. Two patients died from disseminated metastatic disease at 3 and 24 months from the onset of chemotherapy. CMF chemotherapy appears to be an active regimen in the treatment of locally advanced MCC. Further experience with this combination is warranted.

Adult↗
PubMedDate not supplied

Advanced Merkel cell cancer and the elderly.

BACKGROUND: Merkel cell cancer (MCC) is an uncommon neuroendocrine skin cancer occurring predominantly in elderly Caucasians. It tends to metastasize to regional lymph nodes and viscera and is sensitive to chemotherapy but recurs rapidly. AIM: To report one such case, its response to chemotherapy and briefly review the literature. METHODS: A 73-year-old male with a fungating primary lesion on his left knee and ulcerated inguinal lymph nodes was diagnosed with MCC and treated with chemotherapy. The two largest case series and reviews of case reports were summarised. RESULTS: His ulcer healed after two cycles of carboplatin and etoposide with improvement in quality of life. Overall response rates of nearly 60% to chemotherapy are reported but median survival is only nine months with metastatic disease. CONCLUSIONS: Chemotherapy should be considered for fit elderly patients with MCC who have recurrent or advanced disease.

Aged↗
PubMedDate not supplied

Merkel cell carcinoma: report of seven cases.

Merkel cell carcinoma (MCC) is an infrequent, highly malignant, primary skin tumor derived from neuroendocrine cells. Most MCCs occur in elderly individuals, on sun-exposed areas of the body, with the head and neck being the most common sites. We present 7 patients (2 male and 5 female, age 45-80 years) suffering from MCC and treated between 1993 and 2000. All tumors were located on the head and neck and varied from 0.9 to 2.3 cm in size. Five of the patients had stage II disease, 1 patient had stage Ia disease and 1 patient had stage III disease. Six of the patients had positive regional lymph nodes. All patients had local excision of the tumor. Six of them also had lymph node dissection and in 5 of them a superficial parotidectomy was performed. Five patients received adjuvant radiotherapy and 3 of them also received chemotherapy. Local and cervical lymph node recurrence was observed in only 1 patient. Metastases occurred in 5 patients. One patient died within 10 days for other reasons. The patient with the stage III tumor had a survival of 7 months. The other 5 patients had survivals varying from 15 to 54 months. MCC is a skin tumor with very poor prognosis and high recurrence and metastatic rates. Its treatment is still under discussion. Radical excision of the tumor is the main method of treatment. Selective lymph node dissection is suggested. Superficial parotidectomy seems necessary, especially if the tumor is on the auricle. Adjuvant radio- and chemotherapy may extend survival in case of small-size tumors.

Aged↗
PubMed2006

Cisplatin-based chemotherapy for merkel cell carcinoma of the skin.

PURPOSE: Merkel cell carcinoma (MCC), a rare tumor of the skin with aggressive behavior, is usually fatal when advanced disease is present. The role of chemotherapy (CT) in the treatment of patients with MCC is unclear. METHODS: Over 15 years, 9 patients with locally advanced or metastatic disease were treated with carboplatin (CBDCA) (300 mg/m(2) of AUC 5 on Day 1) and etoposide (VP-16) (100 mg/m(2) on Days 1-3) every 3 weeks. As second-line CT, cisplatin (CDDP) (60-100 mg/m(2)), ifosfamide (IFO) (3-5 g/m(2)) and epirubicin (EPI) (30-50 mg/m(2)) were utilized. RESULTS: Of the 3 patients who received adjuvant therapy, one achieved complete response after 108+ months with second-line chemotherapy and radiotherapy, despite a brief relapse; 2 patients remain disease-free after 84+ and 108+ months. Of the 6 patients with locally advanced or metastatic disease who were treated with first-line chemotherapy, one (16.6 percent) achieved a complete response and 3 (50 percent) achieved partial response, for an overall response rate of 66.6 percent. Two patients (one with complete and one with partial response) received subsequent radiotherapy, following which complete response was achieved. Of the 2 complete responders, one patient remains disease-free after 56+ months. The median overall survival from the time of initial diagnosis for the whole group was 56 months (range 15-114 months); the median overall survival from the initiation of chemotherapy was 18 months (range 6-108+). Local recurrences and soft tissue metastases responded better than visceral metastases. Patients with partial response and no response had rapid disease progression and fatality, despite second-line chemotherapy and/or radiotherapy. CONCLUSION: MCC appears to be chemosensitive but can progress rapidly with fatal outcomes. Although the rarity of these tumors precludes randomized trials, a common treatment plan should be utilized by those treating MCC. This may allow some conclusions regarding the optimum treatment of patients with MCC to be drawn in the future.

Aged↗
PubMed2006

Merkel cell carcinoma and multiple primary cancers.

Merkel cell carcinoma (MCC) is an aggressive neuroendocrine tumor of the skin for which causative factors remain largely unknown. The site-specific risks of multiple primary cancers associated with MCC, which may provide insight into etiologic influences, have not been quantified in large population-based studies. We estimated the long-term risk of subsequent primary tumors after a first primary MCC (1,306 patients) and the risk of second primary MCC following other first primary cancers (2,048,739 patients) within 11 population-based cancer registries which report to the National Cancer Institute's Surveillance, Epidemiology, and End Results Program (1986-2002). Patients with first primary MCC were at significantly increased risk of developing a subsequent cancer [standardized incidence ratio (SIR), 1.22; 95% confidence intervals (95% CI), 1.01-1.45; observed (O = 122)], with significant excesses restricted to the first year after diagnosis (SIR, 1.71; 95% CI, 1.21-2.33; O = 39). Significantly elevated site-specific risks were observed for cancers of salivary gland (SIR, 11.55; 95% CI, 2.32-33.76; O = 3), biliary sites other than liver and gallbladder (SIR, 7.24; 95% CI, 1.46-21.16; O = 3), and non-Hodgkin lymphoma (SIR, 2.56; 95% CI, 1.23-4.71; O = 10). Nonsignificantly increased risks of 2-fold or higher were seen for chronic lymphocytic leukemia, and cancers of the small intestine and brain. A significantly increased 1.36-fold risk (95% CI, 1.19-1.55; O = 221) of MCC as a second primary malignancy was observed among patients with all other first primary cancers taken together. In particular, significant 3- to 7-fold excesses of MCC followed multiple myeloma (SIR, 3.70; 95% CI, 1.01-9.47; O = 4), chronic lymphocytic leukemia (SIR, 6.89; 95% CI, 3.77-11.57; O = 14), non-Hodgkin lymphoma (SIR, 3.37; 95% CI, 1.93-5.47; O = 16), and malignant melanoma (SIR, 3.05; 95% CI, 1.74-4.95; O = 16). Although enhanced medical surveillance may play a role, increased reciprocal risks suggest that MCC may share etiologic influences with other malignancies. Heightened awareness of the associations of lymphohematopoietic malignancies with MCC may facilitate early clinical recognition.

Aged↗
PubMed2005

CD56 staining in Merkel cell carcinoma and natural killer-cell lymphoma: magic bullet, diagnostic pitfall, or both?

BACKGROUND: Antibodies to CD56 label natural killer (NK) cell lymphomas and neuroendocrine tumors such as Merkel cell carcinoma (MCC). In MCC altered by crush artifact or obscured by lymphocytes, the histologic features coupled with CD56 positivity can lead to an erroneous impression of NK-cell lymphoma. METHODS: Eighteen cases of MCC were stained for CD56, CK20, MNF116, and pankeratin. The results were compared to histologic features and CD56 staining pattern of three NK-cell lymphomas. RESULTS: Three of 18 cases of MCC histologically resembled lymphoma, and CD56 positivity with CD3 and CD20 negativity initially raised the possibility of NK-cell lymphoma. Two additional cases were obscured by dense inflammation, again suggesting the diagnosis of lymphoma. Seventeen of 18 MCC labeled for CD56 and an equal number stained for CK20. All MCC tested were positive for CAM5.2 (14/14) and MNF116 (17/17). Antibodies to pankeratin labeled only one of 18 MCC. Staining for CD56 was stronger in MCC than NK-cell lymphomas. CONCLUSIONS: CD56 is a sensitive marker for MCC as well as for NK-cell lymphoma, but is not specific. Importantly, CD56 positivity in crushed or inflamed biopsies of MCC may lead to an erroneous impression of NK lymphoma. Awareness of this potential pitfall will prevent misdiagnosis. McNiff JM, Cowper SE, Lazova R, Subtil A, Glusac EJ. CD56 staining in Merkel cell carcinoma and natural killer-cell lymphoma: Magic bullet, diagnostic pitfall, or both?

Aged↗
PubMed1983

[Merkel cell carcinoma (trabecular carcinoma) of the skin].

The Merkel cell carcinoma was first designated some years ago by the descriptive term trabecular carcinoma. Both names refer to a skin tumor occurring in elderly patients. This is another example where ultrastructural differentiating criteria are necessary for a definite diagnosis i.e., identification of so-called neurosecretory-like granules by electron microscopy. We report clinical, histological, ultrastructural, and histogenetic aspects of such a disease in a woman suffering from a metastasizing Merkel cell carcinoma.

Adenocarcinoma↗
PubMedDate not supplied

Association between chronic lymphocytic leukaemia and secondary tumours: unusual occurrence of a neuroendocrine (Merkell cell) carcinoma.

The authors describe a case of cutaneous neuroendocrine (Merkell cell) carcinoma in a patient previously treated for Chronic Lymphocytic Leukaemia (CLL). The authors discuss some of the mechanisms concerning the increased frequency of a second tumour in patients with CLL and focus attention on the high incidence in CLL of secondary tumours, especially skin tumours, of which Merkell cell carcinoma is a rare example. The authors consider the possible therapeutic approaches, reported in the literature, for the treatment of this particular skin carcinoma, which on account of its aggressiveness and the preexistence of a leukaemic process requires a particularly careful therapeutic approach.

Aged↗
PubMed2006

Complete heart block and cardiac tamponade secondary to Merkel cell carcinoma cardiac metastases.

This is a unique case of Merkel cell carcinoma, a rare neuroendocrine tumor, metastasizing to the heart and inducing a progression of cardiac complications such as new-onset atrial fibrillation, malignant pericardial effusion with tamponade physiology, first-degree heart block, and complete heart block. Metastases to the heart are relatively rare but should be suspected if a patient with a known neoplasm presents with new cardiac manifestations. This is the first case report of cardiac metastases from Merkel cell carcinoma causing cardiac tamponade or complete heart block. This case highlights the clinical decision-making involved in managing cardiac tamponade and complete heart block in the setting of metastatic disease to the heart.

Aged↗
PubMed2005

Merkel cell carcinoma in the orbitopalpebral region.

Trabecular carcinoma is a rare cutaneous neuroendocrine carcinoma that probably originates from the Merkel cells that are usually found in the basal layer of the epidermis. The treatment of Merkel cell carcinoma is controversial and there is no specific therapeutic protocol because of the small number of cases that have been published. The procedures used to treat Merkel cell carcinoma must be tailored to minimise morbidity while maximising survival. Because the condition is so rare and difficult to diagnose and treat, we report three cases of orbitopalpebral tumours that confirm the local and regional aggressiveness and the high metastatic potential of this tumour.

Aged↗
PubMed1989

Merkel cell carcinoma. A successful treatment with tumor necrosis factor.

A Merkel cell carcinoma of the mandibular area in a 78-year-old woman was treated successfully by direct intratumoral administration of recombinant human tumor necrosis factor. The patient received 2.5 x 10(5) U/d of recombinant human tumor necrosis factor every other day. A total of six injections (total dose, 1.5 x 10(6) U, 0.52 mg of protein) were administered over a period of 12 days. Soon after the therapy ended, the lesion softened and decreased in size. After 1 month, only erythema was visible. The lesion had completely disappeared clinically and histologically 5 months after the local injection of recombinant human tumor necrosis factor. Neither recurrence nor metastasis has been observed for at least 12 months following the treatment. Recombinant human tumor necrosis factor is suggested to be effective for the treatment of Merkel cell carcinoma.

Aged↗
PubMed1997

The natural history and management of Merkel cell carcinoma of the skin: a review of 22 patients treated at the Royal Marsden Hospital.

Merkel cell carcinoma is a rare skin malignancy, which primarily affects the elderly. Currently, there is only limited data on the natural history of this condition and no consensus on its optimum management. We have reviewed the natural history and management of 22 patients with Merkel cell carcinoma, who were treated at the Royal Marsden Hospital between 1985 and 1994. The median age at diagnosis was 75 years (range 55-96), with the head and neck region being the most common site of disease (nine patients: 41%). Seventeen patients (77%) presented with skin disease, three (14%) with regional lymphadenopathy and two (9%) with metastatic disease. Of the Stage I patients, 41% developed local recurrence postoperatively at a median time to relapse of 12 months. Those with head and neck disease had the highest risk of local recurrence, which occurred in 62.5% of this group. Stage I patients also had a high risk of disease progression, with 53% developing regional lymphadenopathy or visceral metastases. The median survival for all disease stages was 47 months. The treatment of unresectable primary or recurrent disease with radiotherapy led to valuable long term control in four of nine patients treated. Six courses of chemotherapy were administered; one brief complete response was observed, occurring in a patient treated with cyclophosphamide, vincristine and doxorubicin. The data in this study confirms the predilection for the elderly and the aggressive nature of Merkel cell carcinoma, with only four of 17 Stage I patients remaining disease free. To clarify the role of adjuvant postoperative radiotherapy and to establish the appropriate use of chemotherapy in metastatic spread of this rare malignancy will require further studies with multicentre cooperation.

Aged↗
PubMed2001

Clinicopathologic and electron microscopic study of cutaneous neuroendocrine (Merkel cell) carcinoma in a cat with comparisons to human and canine tumors.

Malignant neuroendocrine carcinoma of the skin (Merkel cell tumor) was diagnosed in an 18-year-old spayed female Maine Coon Cat. The diagnosis was made on the basis of morphologic and electron microscopic findings. The cat was euthanatized 321 days after surgical excision of the tumor. The tumor's malignancy contrasted with the benign nature of Merkel cell tumors reported in dogs and was consistent with the malignancy of Merkel cell tumors reported in humans.

Animals↗
PubMed1986

[Merkel-cell tumor associated with a spinocelluar epithelioma. Apropos a case report].

One case of Merkel cell carcinoma is reported in a 71 years-old woman. Lately treated by surgical excision (14 years after the occurrence of the tumour), this tumour was already associated with inguinal lymph node metastases. Its evolution was lethal within 3 months after local recurrence, cutaneous and visceral (lung, liver) metastases. This tumour, characteristic histologically and ultrastructurally (secretory granules), was accompanied by an infiltrative epidermoid carcinoma. This association and the presence of cytokeratin in tumoral Merkel cells are arguments for the common origin of keratinocytes and neuroendocrine Merkel cells from a common young epithelial cell.

Aged↗
PubMed1988

[Clinical aspects and therapy of Merkel cell tumor--report of 4 personal cases and review of the literature].

Four cases of Merkel cell tumor located in the face or on the trunk are presented. In a literature review 339 cases were found and analysed. The Merkel cell tumor is a neuroendocrine tumor of the skin derived from the Merkel cells. It is located most often in the face and neck area. Typically, it is an exophytic node, has a red-blue color and measures 25 mm in diameter on the average. Since it is metastasizing it is a malignant tumor. Regional node metastases were found in 27%, local recurrences occur in 51%, and distant metastases were seen in 32% of the cases. The best therapy is excision with wide margins as is the rule for a malignant skin tumor. While the tumor reacts to radiotherapy, chemotherapy seems to be of no help.

Adult↗
PubMed2003

[Merkel cell carcinoma of the nose].

Despite an increasing number of reports Merkel cell carcinoma still is a rare neoplasm. We therefore present the imaging feature of the case of Merkel cell carcinoma involving the nasal region in 65-year woman with lymphoma malignum lymphoplasmocytoides and its rapid progression with fast metastasis to lymph nodes. Surgery and adjuvant radiotherapy, chemotherapy appeared to provide optimal local control.

Aged↗
PubMedDate not supplied

Methionine-enkephalin immunoreactivity in Merkel cell dense-core granules of nude mice sinus hair. A post-embedding immunogold electron-microscopic study.

The ultra-immunocytochemical technique applied in the present study revealed the occurrence of methionine-enkephalin (met-enkephalin)-like substance in the dense-core granules of Merkel cells of nude mice sinus hair. Incubation of ultra-thin sections of sinus hair with met-enkephalin antisera conjugated with gold particles showed specific association of gold particles on the dense-core granules of the Merkel cells. Gold particles were heavily and specifically located on the dense-core granules as well as in the adjacent cytoplasm. Dense-core granules of degenerating Merkel cells also exhibit met-enkephalin immunoreactivity. The nerve terminals associated with the Merkel cell did not show met-enkephalin immunoreactivity. Therefore, it is concluded that a met-enkephalin-like substance is present and stored in nude mice Merkel cell dense-core granules and it might act as a neurotransmitter or neuromodulator which could be involved in the functioning of the cell. Non-osmicated tissue should be used to locate this substance because of the possibility of cross-linkage of the amino acid sequence with osmium tetroxide.

APUD Cells↗