Merkel-cell carcinoma of the skin

[The role of lymphoscintigraphy in the treatment of Merkel´s cells carcinoma]

The Merkel cell carcinoma is a rare, serious, neuroendocrine, malignant skin cancer with lymph node involvement in half of patients and disseminated metastases in 20% of cases at the time of pathological diagnosis. Its treatment is not fully established, though the sentinel lymph node has been considered essential and may bring benefits to the therapeutic armamentarium of patients.

Merkel cell carcinoma: the prognostic implications of an occult primary in stage IIIB (nodal) disease

BACKGROUND

Merkel cell carcinoma is a highly aggressive cutaneous malignancy with a high rate of lymph node and distant metastatic disease. Approximately one third of patients present with stage IIIB (nodal) disease.

OBJECTIVE

This cohort study was performed to analyze the outcome of patients with stage IIIB disease with or without an occult primary.

METHODS

The details of 91 patients with stage IIIB (nodal) Merkel cell carcinoma treated curatively between 1985 and 2010 at 3 tertiary referral hospitals in Australia were reviewed. Kaplan-Meier plots were used with the primary end point being overall survival. Secondary end points were disease-free survival and relapse-free survival. A multivariate Cox regression analysis was performed for known prognostic factors.

RESULTS

Of 91 patients with stage IIIB (nodal) disease, 36 (40%) had an occult primary. A total of 78 patients (86%) had surgery and 79 patients (87%) had definitive or adjuvant radiotherapy. With a median follow-up of 4.3 years, those with an occult primary did significantly better in terms of overall survival, disease-free survival, and relapse-free survival. On multivariate analysis, occult primary and patient age were the only factors predicting survival with hazard ratios of 0.30 (95% confidence interval 0.13-0.67) and 1.64 (95% confidence interval 1.13-2.38), respectively.

LIMITATIONS

This is a retrospective study over several decades with patients treated using various modalities.

CONCLUSION

This study indicates that for patients with stage IIIB (nodal) Merkel cell carcinoma, the presence of an occult primary confers a significantly better prognosis that may have implications in the future staging and treatment of patients with stage III disease.

Skin cancer in solid organ transplant recipients: advances in therapy and management: part I. Epidemiology of skin cancer in solid organ transplant recipients

Skin cancer is the most frequent malignancy in organ transplant recipients, 95% of which are nonmelanoma skin cancer, especially squamous cell and basal cell carcinomas. This paper also discusses the incidence of other tumors (eg, melanoma, Merkel cell carcinoma, and Kaposi sarcoma) that are also increased in organ transplant patients compared to the general population. Part I of this two-part series describes the latest data concerning the epidemiologic and pathogenic aspects of nonmelanoma skin cancer development in solid organ transplant recipients. This review also highlights the concept of "field cancerization," represented by extensive areas of actinic damage and epidermal dysplasia, which accounts for increased risk of aggressive skin cancer development in susceptible patients.

Expression of stem cell markers nestin and cytokeratin 15 and 19 in cutaneous malignancies

BACKGROUND

Emerging evidence is implicating stem cells in the pathogenesis of different cutaneous neoplasms. The immunohistochemical use of stem cell markers has facilitated stem cell identification. While few studies have examined the expression of cytokertatin (CK)15 and cytokeratin (CK)19 in basal cell carcinoma (BCC) and squamous cell carcinoma (SCC), only rarely have nestin expression been examined in these two malignancies. Furthermore, stem cell marker expression, to the best of our knowledge, has not been examined in Merkel cell carcinoma (MCC).

METHODS

In this study, we examined the expression of stem cell markers CK15, CK19 and nestin in 51 overall cases (11 cases of MCC and 20 cases each of BCC and SCC) retrieved from the pathology files of Skin Pathology Laboratory, Boston University School of Medicine.

RESULTS

Cytokeratin 15 immunoreactivity was observed in 30% of BCC cases and only a single (5%) SCC case, while all MCC cases were negative. While 60% of BCC cases and 30% of SCC cases stained positively with CK19, all MCC cases showed positive immunostaining in a dot-like pattern. While negative in BCC and MCC, nestin expression was interestingly seen in 45% of SCC cases.

CONCLUSIONS

Our study described the expression profiles of stem cell markers CK15, CK19 and nestin in BCC, SCC and MCC. In addition to confirming results of the previous reports, our study also showed positive nestin expression in around half of SCC cases, which adds this malignancy to the cutaneous tumours that have been so far reported to exhibit nestin expression.

Merkel cell polyomavirus DNA sequences in the buffy coats of healthy blood donors

Merkel cell polyomavirus (MCPyV), a DNA tumor virus, has been found to be associated with Merkel cell carcinoma and chronic lymphocytic leukemia. MCPyV sequences have also been detected in various normal tissues in tumor-affected patients. Immunologic studies have detected MCPyV antibodies in as many as 80% of healthy blood donors. This high seroprevalence suggests that MCPyV infection is widespread in humans. In our study, buffy coats, which were examined for MCPyV DNA Tag sequences, showed a prevalence of 22%. Viral DNA load was revealed in blood samples from 10 to 100 molecules/100 000 cells. DNA sequencing confirmed that polymerase chain reaction amplicons belong to the MCPyV strain, MKL-1. To interpret the putative role of MCPyV in chronic lymphocytic leukemia, we may infer that, during a long period of viral persistence in blood cells, this DNA tumor virus may generate mutants, which are able to participate as cofactors in the multistep process of cell transformation.

Large cell neuroendocrine carcinoma of the ampulla of vater with adenocarcinoma and squamous cell carcinoma components

A 73-year-old woman visited our hospital complaining of general fatigue and jaundice. Laboratory tests revealed an elevated total bilirubin, aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase and γ-glutamyltransferase. Computed tomography and magnetic resonance imaging demonstrated a mass lesion at the ampulla of Vater with dilatation of the common bile duct and main pancreatic duct. Percutaneous transhepatic cholangiography revealed dilatation of the bile duct and a negative filling defect due to the tumor. Pancreatoduodenectomy was performed. The specimen included an ulcerated firm tumor of the papilla Vater. The surface of the ampulla consisted of well-differentiated papillary adenocarcinoma, whereas the deep layer, such as submucosal or muscular layer, contained large cell neuroendocrine carcinoma and squamous cell carcinoma. Immunohistochemistry revealed that the large cell neuroendocrine carcinoma component was positive for chromogranin A, synaptophysin and CD56. The patient died from multiple liver and bone metastases 13 months after surgery. This is a very rare case of a large cell neuroendocrine carcinoma accompanied by adenocarcinoma and squamous cell carcinoma components.

Merkel cell carcinoma: incidence, mortality, and risk of other cancers

BACKGROUND

Merkel cell carcinoma (MCC) is a rare skin cancer that was recently found to be associated with a polyomavirus and with immunosuppression, provoking new interest in its epidemiology. We conducted a nationwide study in Denmark to describe MCC incidence and mortality and the association between MCC and other cancers.

METHODS

We used data from Danish national health and population registers on MCC diagnoses, deaths, and population counts during the study period (1978-2006) to calculate MCC incidence rates, cumulative risks of MCC at age 100 years, and MCC mortality rates by tumor stage. We used Poisson regression to estimate the excess mortality rate ratio attributable to MCC and examined associations between MCC and other cancers diagnosed before and after the MCC diagnosis using standardized incidence rate ratios (SIRs). All statistical tests were two-sided.

RESULTS

Between January 1, 1978, and December 31, 2006, 185 persons were diagnosed with MCC in Denmark. MCC incidence between 1995 and 2006 was 2.2 cases per million person-years. In the first year after MCC diagnosis, 22% of persons with localized disease died compared with 54% of patients with nonlocalized disease; by 5 years after diagnosis, the proportions of MCC patients who had died increased to 55% and 84%, respectively. MCC incidence was statistically significantly increased more than 1 year after a diagnosis of squamous cell carcinoma of the skin (SIR = 14.6, 95% confidence interval [CI] = 8.4 to 25.6), basal cell carcinoma (SIR = 4.3, 95% CI = 2.7 to 6.6), malignant melanoma (SIR = 3.3, 95% CI = 1.1 to 10.3), chronic lymphocytic leukemia (SIR = 12.0, 95% CI = 3.8 to 37.8), Hodgkin lymphoma (SIR = 17.6, 95% CI = 2.5 to 126), and non-Hodgkin lymphoma (SIR = 5.6, 95% CI = 1.4 to 22.4). Squamous cell carcinoma (SIR = 12.1, 95% CI = 5.1 to 29.1) and chronic lymphocytic leukemia (SIR = 14.7, 95% CI = 3.7 to 58.8) occurred in statistically significant excess more than 1 year after MCC diagnosis.

CONCLUSIONS

These results support the existence of shared risk factors for MCC and other cancers. Heightened awareness of the association between MCC and other cancers, particularly squamous cell carcinoma and chronic lymphocytic leukemia, may facilitate earlier clinical detection and treatment of MCC, thereby improving patient survival.

Updated Review of the Pathogenesis and Management of Merkel Cell Carcinoma

Background:

Merkel cell carcinoma is a rare, aggressive, malignant cutaneous tumor of the elderly or immunosuppressed individuals that usually appears on sun-exposed areas of the body. Its pathogenesis is still debated, and, currently, no standardized treatment exists.

Objective:

To provide a current updated review of the most relevant data concerning the pathogenesis and management of Merkel cell carcinoma.

Methods:

Using relevant MeSH terms, we performed a review of the literature on these subjects from 1980 to June 2009.

Results and Conclusion:

The current management of Merkel cell carcinoma is based on surgical excision as the majority of patients present with localized disease, whereas up to 30% have regional lymph node metastases. In these cases, the best outcome is achieved with multidisciplinary management that includes radiotherapy. Chemotherapy is part of the treatment in advanced cases and is mandatory for distant metastatis. Given that a recent work showed the presence of a previously unknown polyomavirus, which the authors called Merkel cell polyomavirus, the therapeutical approach to Merkel cell carcinoma could be reconsidered in the future.

Ileocaecal recurrence of Merkel cell carcinoma of the skin: a case report

Introduction

Merkel cell carcinoma is an uncommon skin malignancy that has a high propensity for metastatic spread. A systematic literature search identified 17 cases describing metastasis to the gastrointestinal tract, with 7 cases involving the small or large bowel. To the best of our knowledge, this is the only case described of Merkel cell carcinoma metastasising to the ileocaecal valve.

Case presentation

We present a 74-year-old Filipino woman diagnosed with Merkel cell carcinoma of the skin with regional node involvement. Following excision and radiotherapy, the tumour recurred with metastasis to the ileocaecal valve. The patient died 28 months after the initial diagnosis.

Conclusion

The prognosis of metastatic Merkel cell carcinoma is poor. Currently the optimal management for metastatic disease is unclear and lacks a firm evidence base due to the small number of cases reported.

[Management of Merkel cell carcinoma: Role of radiotherapy in elderly patients]

PURPOSE

Merkel cell carcinoma carcinoma (MCC) or primary cutaneous neuroendocrine carcinoma is a rare and aggressive malignancy affecting elderly. Optimal therapeutic strategy has not yet been established in elderly patients.

PATIENTS AND METHODS

From March 1996 to March 2007, 29 patients with Merkel cell carcinoma of were treated at the University Hospital of Amiens, France. Adjuvant radiotherapy (RT) was performed for 14 patients (50%) on the tumor bed with margins of 3 to 5cm, an average dose of 46Gy (30-60Gy), by 2Gy per fraction. Ten of them also received RT to the lymph node area at mean dose of 44.3Gy (26-50Gy). Duration of RT was 35 days. A retrospective analysis was conducted to better evaluate survival and prognostic factors.

RESULTS

Median overall survival (OS) was 18.9 months (3-122) and the median time to progression (MTP) 5.5 months (1-26). At 5 years, OS for irradiated patients was 47% (IC95: 12-82%) versus 27% (IC95: 5-49%) in cases of surgery alone (p=0.032). The most frequent sites of recurrence were nodal (34.5%), local (24.1%) and metastatic (17.2%). For patients over 70 years, eight (36.5%) were free of disease at last news, 8 (36.5%) had died from cancer and six from other causes (27%). In this subgroup, MTP was 6 months (2-19) and median OS of 19 months (4-87). There was no acute toxicity greater than grade 2.

CONCLUSION

Although limited by a retrospective analysis, this report suggests an advantage of postoperative RT for patients with MCC. It combined low toxicity and improvement of survival. Prospective multicenter trials are needed to clarify and validate the optimal strategy.

Effect of radiotherapy dose and volume on relapse in Merkel cell cancer of the skin

PURPOSE

To assess the effect of radiotherapy (RT) dose and volume on relapse patterns in patients with Stage I-III Merkel cell carcinoma (MCC).

PATIENTS AND METHODS

This was a retrospective analysis of 112 patients diagnosed with MCC between January 2000 and December 2005 and treated with curative-intent RT.

RESULTS

Of the 112 evaluable patients, 88% had RT to the site of primary disease for gross (11%) or subclinical (78%) disease. Eighty-nine percent of patients had RT to the regional lymph nodes; in most cases (71%) this was for subclinical disease in the adjuvant or elective setting, whereas 21 patients (19%) were treated with RT to gross nodal disease. With a median follow-up of 3.7 years, the 2-year and 5-year overall survival rates were 72% and 53%, respectively, and the 2-year locoregional control rate was 75%. The in-field relapse rate was 3% for primary disease, and relapse was significantly lower for patients receiving >or=50 Gy (hazard ratio [HR] = 0.22; 95% confidence interval [CI], 0.06-0.86). Surgical margins did not affect the local relapse rate. The in-field relapse rate was 11% for RT to the nodes, with dose being significant for nodal gross disease (HR = 0.24; 95% CI, 0.07-0.87). Patients who did not receive elective nodal RT had a much higher rate of nodal relapse compared with those who did (HR = 6.03; 95% CI, 1.34-27.10).

CONCLUSION

This study indicates a dose-response for subclinical and gross MCC. Doses of >or=50 Gy for subclinical disease and >or=55 Gy for gross disease should be considered. The draining nodal basin should be treated in all patients.

Association of Merkel cell polyomavirus-specific antibodies with Merkel cell carcinoma

BACKGROUND

Merkel cell polyomavirus (MCPyV) has been detected in approximately 75% of patients with the rare skin cancer Merkel cell carcinoma. We investigated the prevalence of antibodies against MCPyV in the general population and the association between these antibodies and Merkel cell carcinoma.

METHODS

Multiplex antibody-binding assays were used to assess levels of antibodies against polyomaviruses in plasma. MCPyV VP1 antibody levels were determined in plasma from 41 patients with Merkel cell carcinoma and 76 matched control subjects. MCPyV DNA was detected in tumor tissue specimens by quantitative polymerase chain reaction. Seroprevalence of polyomavirus-specific antibodies was determined in 451 control subjects. MCPyV strain-specific antibody recognition was investigated by replacing coding sequences from MCPyV strain 350 with those from MCPyV strain w162.

RESULTS

We found that 36 (88%) of 41 patients with Merkel cell carcinoma carried antibodies against VP1 from MCPyV w162 compared with 40 (53%) of the 76 control subjects (odds ratio adjusted for age and sex = 6.6, 95% confidence interval [CI] = 2.3 to 18.8). MCPyV DNA was detectable in 24 (77%) of the 31 Merkel cell carcinoma tumors available, with 22 (92%) of these 24 patients also carrying antibodies against MCPyV. Among 451 control subjects from the general population, prevalence of antibodies against human polyomaviruses was 92% (95% CI = 89% to 94%) for BK virus, 45% (95% CI = 40% to 50%) for JC virus, 98% (95% CI = 96% to 99%) for WU polyomavirus, 90% (95% CI = 87% to 93%) for KI polyomavirus, and 59% (95% CI = 55% to 64%) for MCPyV. Few case patients had reactivity against MCPyV strain 350; however, indistinguishable reactivities were found with VP1 from strain 350 carrying a double mutation (residues 288 and 316) and VP1 from strain w162.

CONCLUSION

Infection with MCPyV is common in the general population. MCPyV, but not other human polyomaviruses, appears to be associated with Merkel cell carcinoma.

Unusual skin tumors: Merkel cell carcinoma, eccrine carcinoma, glomus tumors, and dermatofibrosarcoma protuberans

This article discusses the epidemiology, etiology, presentation, pathology, evaluation and staging, and treatment of unusual skin tumors, such as Merkel cell carcinoma, eccrine carcinoma, glomus tumors, and dermatofibrosarcoma protuberans.

Metastatic Merkel cell carcinoma with positive expression of thyroid transcription factor-1--a case report

We report on a case of metastatic Merkel cell carcinoma in a 74-year-old patient with positive staining for thyroid transcription factor-1. This represents a new immunohistochemical staining pattern for Merkel cell carcinoma and has implications regarding the accurate diagnosis of this tumor type.

Clinical course and prognostic factors of Merkel cell carcinoma of the skin

BACKGROUND

Merkel cell carcinoma (MCC) is a rare neuroendocrine malignancy of the skin first described by Toker as 'trabecular carcinoma of the skin' in 1972. To date, the origin of the tumour cells still remains unclear.

OBJECTIVES

The present study analyses prognostic factors of MCC.

PATIENTS AND METHODS

The medical records of 57 patients with MCC treated between 1988 and 2006 at the Department of Dermatology in Tübingen were reviewed.

RESULTS

We identified 26 (45.6%) male and 31 (54.4%) female patients with MCC; the age at diagnosis ranged from 26 to 97 years (median 71 years). Primary tumours were located mainly on the head and neck areas (27 cases, 47.4%) and upper extremities (14 cases, 24.6%); 11 tumours were found on the lower extremities (19.3%) and four lesions on the chest (7%); one patient had an unknown primary location. Forty-five (78.9%) patients were diagnosed at stage I of the disease, 11 (19.3%) at stage II, and one patient (1.8%) at stage III at initial presentation. Stage of the disease and age at initial presentation were statistically significant with regard to overall (P < 0.0001; P = 0.0327) and tumour-specific survival (P < 0.0001; P = 0.0156). Use of the Cox regression model revealed initial stage of the disease as the only significant factor in the multivariate analysis. Radiotherapy applied promptly after excision of the primary tumour extended the time to progression significantly (P = 0.0376) but did not prolong overall or tumour-specific survival. Other parameters such as sex, site of tumour, sentinel node biopsy, excision margins, skin and noncutaneous malignancies were found to be not significant.

CONCLUSIONS

Currently, early recognition of the disease seems to be the only method of ensuring overall survival. However, evidence-based treatment modalities are still urgently needed.

[Merkel cell carcinoma]

A 67-year old patient developed multiple flesh-colored nodules on the back of his left hand. Histological examination led to the diagnosis of a Merkel cell carcinoma (MCC). This highly aggressive primary cutaneous tumor is classified as a neuroendocrine carcinoma. It affects mostly elderly and immunosuppressed patients. Recently, a new polyomavirus (MCPyV) has been detected in about 75-85% of MCC and seems to play an important role in their pathogenesis. This new finding may help to develop new therapeutic options for MCC.

Ultrastructural proof of polyomavirus in Merkel cell carcinoma tumour cells and its absence in small cell carcinoma of the lung

BACKGROUND

A new virus called the Merkel Cell Polyomavirus (MCPyV) has recently been found in Merkel Cell Carcinoma (MCC). MCC is a rare aggressive small cell neuroendocrine carcinoma primarily derived from the skin, morphologically indistinguishable from small cell lung carcinoma (SCLC). So far the actual presence of the virus in MCC tumour cells on a morphological level has not been demonstrated, and the presence of MCPyV in other small cell neuroendocrine carcinomas has not been studied yet.

METHODOLOGY/PRINCIPAL FINDINGS

We investigated MCC tissue samples from five patients and SCLCs from ten patients for the presence of MCPyV-DNA by PCR and sequencing. Electron microscopy was used to search ultrastructurally for morphological presence of the virus in MCPyV-DNA positive samples. MCPyV was detected in two out of five primary MCCs. In one MCC patient MCPyV-DNA was detected in the primary tumour as well as in the metastasis, strongly suggesting integration of MCPyV in the cellular DNA of the tumour in this patient. In the primary MCC of another patient viral particles in tumour cell nuclei and cytoplasm were identified by electron microscopy, indicating active viral replication in the tumour cells. In none of the SCLCs MCPyV-DNA was detected.

CONCLUSIONS/SIGNIFICANCE

Our results strongly suggest that MCPyV is an oncogenic polyomavirus in humans, and is potentially causally related to the development of MCC but not to the morphological similar SCLC.

Merkel cell carcinoma of the face: an analysis of 16 cases in the Japanese

BACKGROUND

There is no agreement regarding a staging system and optimal treatment of Merkel cell carcinoma. Some centres have reported results from larger series of patients, but these do not include Asian or Japanese centres.

OBJECTIVE

The purpose of this study was to retrospectively review our experience with the surgical treatment of MCC of the face in the Japanese and to study its management and outcome using the staging system described by Clark et al.

METHODS

We report our experiences with 16 cases between 1991 and 2004. Patients and tumour characteristics, treatment variables and outcome were analysed.

RESULTS

The follow-up periods ranged from 1 to 180 months. The average was 32.6 months and the median was 17.5 months. The relapse-free survival for all patients was 51% at 2 years. The relapse-free survival was 80% for the patients with Stage I and 33% with Stage II at 2 years.

CONCLUSION

This staging system was suggested to reflect prognosis although the number of patients in this series was small. Sentinel lymph node biopsy should be considered to determine the accurate nodal staging, and patients with MCC of the head and neck may be treated according to the revised staging system by Clark et al.

Comparison of CD23 staining patterns in Merkel cell carcinoma and non-cutaneous small cell carcinoma

BACKGROUND

During our daily practice, we observed that cluster designation 23 (CD23) (clone BU38) labels Merkel cells in normal skin. In this study, we examined the expression of CD23 in Merkel cell carcinoma (MCC) and assessed its usefulness in distinguishing MCC from non-cutaneous small cell carcinoma (SMCC).

METHODS

Immunohistochemical staining of CD23 was performed on a total of 33 MCCs, 22 SMCCs and 5 carcinoid tumors.

RESULTS

CD23 reactivity was present in 32 of 33 (97%) MCCs, 18 of 22 (82%) SMCCs and 5 of 5 (100%) carcinoid tumors. In MCC, 19 cases (59%) showed a predominance of perinuclear dot-like staining similar to cytokeratin 20, 3 (9%) showed mostly cytoplasmic staining and 10 (31%) displayed a combination of perinuclear dot-like and cytoplasmic staining. In contrast, all CD23-positive SMCCs and carcinoid tumors showed a diffuse cytoplasmic staining. There was a significant difference in the CD23 staining patterns between MCC and SMCC (p < 0.0001).

CONCLUSION

CD23 is expressed in the majority of MCC, SMCC and carcinoid tumor irrespective of clinical outcome. The distinct punctate CD23 staining for MCC may be helpful in differentiating it from SMCC. To our knowledge, this is the first study to show the expression of CD23 in neuroendocrine tumors.

Interferon-alpha inhibits proliferation and induces apoptosis of merkel cell carcinoma in vitro

Merkel cell carcinoma is a tumor with aggressive biological behavior and limited response to chemotherapy. The present study investigated the effect of interferon (IFN)-alpha on growth and apoptosis of Merkel carcinoma cells in vitro. Proliferation of MCC-1 cell line was reduced dose-dependently by IFN-alpha and diminished when higher IFN-alpha concentrations were used. Additionally, IFN-alpha potently decreased DNA-synthesis and Ki67/MIB-1 proliferation index of MCC-1 cultures. Furthermore, IFN-alpha induced dose-dependently apoptosis of MCC-1 cells as shown by caspase-3 activation, and detection of apoptotic DNA strand breaks and fragmented nuclei. These findings suggest that IFN-alpha may have antitumor activity against Merkel cell carcinoma.

The important role of radiotherapy in patients with non-melanoma skin cancer and other cutaneous entities

Non-melanoma skin cancer is the commonest malignancy worldwide and a significant public health issue. Although most non-melanoma skin cancers are small and easily excised or ablated, a recommendation of definitive radiotherapy is often made in patients where the outcome (cosmetic and/or functional) will probably be better with radiotherapy compared to surgery. The aim of adjuvant radiotherapy is to reduce the risk of loco-regional recurrence and the role of palliative radiotherapy is important in improving the quality of life in patients with advanced and/or incurable disease. The aim of this review article is to broadly discuss the various clinical settings in which a recommendation of radiotherapy may be made and also includes a discussion on less frequently encountered cutaneous entities (e.g. in situ squamous cell carcinoma, keratocanthoma, lentigo maligna, cutaneous lymphomas and malignant fibrous tumours).

A comparison of merkel cell carcinoma and melanoma: results from the california cancer registry

INTRODUCTION

Melanoma and Merkel cell carcinoma (MCC) are both aggressive skin malignancies associated with immunosuppression and possible UV exposure. Both tumors get similar surgical treatment; however, MCC is a relatively rare tumor in which less is known about prognosis and clinical behavior.

METHODS

The California Cancer Registry (CCR), a population-based registry, was reviewed from the years 1988-2003. Merkel cell carcinoma and melanoma were compared with relation to gender, age, ethnicity, disease stage, site, and survival.

RESULTS

A total of 113,187 cases of melanoma and 1,878 cases of MCC were identified in the CCR. Though both cancers are more common in men than in women, MCC had a higher incidence in men than melanoma (63% vs 57% p < 0.005). MCC occurs in the more elderly, with 73.6% of cases occurring in people over 70 years. In contrast, 69% of melanoma cases occurred in people younger than 70 years (p < 0.005). MCC shows a predilection for the head and neck compared to melanoma (47% vs 25.8%) Additionally, melanoma occurs more frequently on the trunk than MCC (30% vs 8.7%). Finally, the 10-year cumulative survival is lower for MCC than for melanoma (17.7% vs 61.3%, p < 0.005).

CONCLUSION

Many clinicians assume MCC and melanoma behave similarly. However, MCC occurs in an older population, more frequently on the head and neck, in a higher percentage of men. Additionally, MCC has a higher rate of regional metastasis and thus may have more of a benefit from regional staging procedures. Overall, MCC has a worse prognosis.

Complete spontaneous regression in Merkel cell carcinoma

Merkel cell carcinoma is a rare, aggressive, cutaneous malignancy of the elderly with a generally poor prognosis. Like all skin cancers, its incidence is rising. A few reports of spontaneous regression have been published. The case of a 67-year-old female patient who presented with a cheek Merkel cell carcinoma is described. Following biopsy it underwent complete regression with no evidence of residual tumour in the excision specimen taken seven weeks later. The current knowledge of Merkel cell carcinoma and the other cases of spontaneous regression described in the literature are reviewed.

Merkel Cell Carcinoma of the Eyelid

PURPOSE

To evaluate the clinical and histopathologic characteristics of Merkel cell carcinoma (MCC) of the eyelid.

DESIGN

Retrospective case series and literature review.

PARTICIPANTS

Three consecutive patients with MCC of the eyelid who were referred to the Ocular Oncology Unit of Leiden University Medical Center, Netherlands.

METHODS

Clinical records and histopathologic material of patients with eyelid MCC were reviewed. The clinical presentation and treatment were evaluated.

MAIN OUTCOME MEASURES

Clinical and histopathologic description of eyelid MCC, with histologic proof of spontaneous regression of the tumor.

RESULTS

Three patients with MCC of the eyelid were included. Diagnosis was made by pathologic investigation and immunohistochemistry (S100, cytokeratin 20, epithelial membrane antigen, chromogranin). Two of the patients showed histologically proven complete spontaneous regression after nonradical excision of the tumor. After local excision, none of the MCCs demonstrated local recurrence, without regional or distant metastases. Mean clinical follow-up was 50 months.

CONCLUSIONS

Nonocular MCC is known to recur in 66% of patients and to be lethal in almost 33%. Merkel cell carcinoma of the eyelid is a rare malignancy that can not be recognized clinically. Clinical differential diagnosis must be made with a chalazion, and histopathologic differential diagnosis must be made with small cell carcinomas. Close follow-up of these patients is advised because of the potential high recurrence rate and lymphatic spread. The immunologic phenomenon of spontaneous regression points out the importance of the immune system in this disease.

Metastatic Merkel cell carcinoma in the rectum: report of a case

Merkel cell carcinoma is a rare, aggressive skin malignancy of neuroendocrine origin with predominant occurrence in the elderly males. Approximately 50 percent of patients with Merkel cell carcinoma develop distant metastasis at some point during the disease course; hence, Merkel cell carcinoma always has a poor prognosis. Distant metastasis has never been disclosed in the rectum to the best of our knowledge. We present a 76-year-old male with clinical manifestation of massive hematochezia and final diagnosis of metastatic Merkel cell carcinoma in the rectum. We conclude that radical resection of rectal metastatic Merkel cell carcinoma is important in the management strategy of a patient with recurrence and lymph node metastases.

RKIP does not contribute to MAP kinase pathway silencing in the Merkel Cell Carcinoma cell line UISO

Background

The Raf kinase inhibitor protein (RKIP) has been shown to block MAP kinase pathway as well as NFκB signalling. By means of immunohistochemistry, we previously demonstrated that the MAP kinase pathway is virtually inactive in Merkel cell carcinoma (MCC). Similarly to MCC in situ high RKIP expression accompanies absence of ERK phosphorylation in the MCC cell line UISO suggesting that RKIP might be causative for MAP kinase pathway silencing.

Methods

Applying an siRNA approach RKIP expression was knocked down in UISO cells and a possible influence on MAP kinase pathway activity was assessed by Western blot analysis using phospho-specific antibodies. Moreover, a possible effect of RKIP knock down in UISO cells on proliferation as well as chemosensitivity to cisplatin were examined applying the MTS assay.

Results

Surprisingly the absence of phosphorylation of the MAP kinases ERK1 and ERK 2 even following growth factor stimulation was not affected by the RKIP knock down indicating that RKIP is not essential for blocking the MAP kinase pathway in the MCC cell line UISO. Moreover, proliferation as well as chemosensitivity towards cisplatin were not altered upon knock down of RKIP.

Merkel cell carcinoma in a liver transplant patient

Merkel cell carcinoma (MCC) is an aggressive tumor, the incidence of which is seemingly increased in immunocompromised patients. We report on a new case of MCC occurring in a 69-year-old male liver transplant recipient 6.5 years after transplantation. The outcome was marked by early skin and lymph node relapses treated by radiotherapy alone, and the patient ultimately died 30 months after first diagnosis. Together with data from the literature, this case emphasizes the importance of early diagnosis and adequate management of this aggressive disease for which wide initial surgical excision, accurate staging, and close follow-up are of critical importance to outcome, especially in this setting of immunosuppressive treatment, which is usually associated with a higher rate of recurrence.

Merkel cell carcinoma metastasizing to the kidney mimicking primary neuroendocrine renal cancer

A 56-year-old male with a history of cutaneous neuroendocrine (Merkel cell) carcinoma presented with a solid mass of the left kidney, measuring 10 cm in largest diameter. On histology, the tumour was composed of loosely packed uniform cells with round-to-oval nuclei and scant cytoplasm. Immunohistochemically, the tumour cells diffusely expressed pancytokeratin and neuroendocrine markers, such as chromogranin A, synaptophysin and CD56 (NCAM). Distinct paranuclear dot-like expression of cytokeratin 20 showed the lesion to be metastatic Merkel cell carcinoma. This is the first reported case of Merkel cell carcinoma metastatic to the kidney mimicking primary neuroendocrine renal cancer. We discuss the differential diagnosis of the tumour and perform a systematic literature review, including potential indications for renal tumour biopsy in patients with a history of nonrenal malignancy.

An unusual case of Merkel cell carcinoma

PURPOSE

Merkel cell carcinoma (MCC) is a rare aggressive neuroendocrine tumor of the skin mainly found in elderly white patients. Due to its poor prognosis with distant metastases in up to 33% and local recurrence in 25-33% and a 5 year disease-specific survival of 64% (1-2) its early diagnosis and appropriate treatment is mandatory.

METHODS

The study is an exceptional clinical case of a patient with a large inoperable MCC unable to be treated according to treatment guidelines due to her old age. We review the literature addressing treatment options.

RESULTS

The patient was treated with palliative definitive radiotherapy to her large MCC of the left lower leg. She showed a rapid clinical response to four palliative radiation doses of 7 Gy each, necrosis of tumor mass and persistent clearing at a follow-up of 32 weeks. Our patient was very unusual in terms of her extensive MCC and her rapid and complete response to palliative radiotherapy lasting for 6 months at present.

CONCLUSIONS

As MCC is an aggressive tumor, best survival is achieved with early diagnosis in a localized stage and prompt adequate surgery and further stage-adjusted treatment. Thus, the differential diagnosis of MCC should not be dismissed in a reddish nodule on the leg, and every excision should be submitted to pathology. In accordance with the literature we demonstrate here that definitive radiotherapy is an effective treatment option for inoperable MCC, which in this individual patient produced necrosis of the extensive tumor mass after only four palliative doses.

Merkel cell carcinoma and HIV infection: a case report and review of the literature

Merkel cell carcinoma (MCC) is a skin cancer of neuroendocrine origin that occurs most often in sun-exposed areas. In the general population, it is a disease of older adults, with only 5% of cases occurring below the age of 50 years. Immunosuppression is the significant risk factor for the development of MCC and recently it was suggested that individuals with HIV have a relative risk of 13.4 to developed MCC in comparison with the general population. We report a case of MCC in an HIV-infected patient and we review nine patients with HIV with MCC. Our patient was a 54-year-old man who came to our attention without a known HIV diagnosis. He was apparently in good health and had no risk factor for HIV, but by the atypical site of the lesion and by the relative young age of the patient we suspected a case of immunosuppression and for this reason we did HIV test that had a positive result. The patient was treated with surgery and chemotherapy but died as a result of liver metastases 25 months after his tumor was diagnosed.

Activation of the MAP kinase pathway induces apoptosis in the Merkel cell carcinoma cell line UISO

Merkel cell carcinoma (MCC) is a rare but highly aggressive tumor of the skin. Recently, we have shown that MCC cells in situ are characterized by a complete absence of mitogen-activated protein kinase (MAPK) pathway signaling, which is preserved in the MCC cell line UISO. Here we present data suggesting that silencing of the MAPK pathway is essential for the survival of MCC cells. Activation of the MAPK pathway could be achieved by inducing a regulatable form of the c-Raf-1 kinase domain in UISO cells. Consequently, MAPK signaling led to morphological changes, loss of actin stress fibers, and induction of apoptosis, which could be prevented by the MAP kinase kinase-specific inhibitor U0126. Hence, despite the fact that activation of the MAPK pathway contributes to oncogenesis in many cancers, it seems to be a negative selection factor for MCC cells. Since ERK phosphorylation was also inducible by the Raf-activating pharmacological agent ZM336372, these results provide new perspectives for potential therapeutics for this highly aggressive tumor.

Merkel cell carcinoma of the head and neck: is adjuvant radiotherapy necessary?

BACKGROUND

Controversy exists regarding the optimal management of patients with Merkel cell carcinoma. The primary aim of this study was to determine whether combined treatment with surgery and radiotherapy improves outcome in a multi-institutional cohort of patients with Merkel cell carcinoma of the head and neck. The secondary aims were to determine by stage, which patients derive benefit from combined therapy and to identify predictors for survival on multivariable analysis.

METHODS

A retrospective analysis of 110 patients with Merkel cell carcinoma of the head and neck was performed. Data were collected from 3 tertiary care institutions (Westmead Hospital, Sydney, Australia; Princess Margaret Hospital, Toronto, Canada; Royal Prince Alfred Hospital, Sydney). There were 78 males and 32 females, median age was 70 years, and mean follow-up of survivors was 2.3 years. Sixty-six patients underwent combined treatment, and 44 patients had either surgery or radiotherapy alone. Analysis by stage was performed using 2 staging systems.

RESULTS

Local and regional control at 5 years was 84% and 69%, respectively. Combined treatment improved both local (p = .009) and regional control (p = .006). Overall and disease-specific survival at 5 years was 49% and 62%, respectively. Combined treatment was associated with significantly better disease-free survival on univariable analysis (p = .013) When analyzed by stage, patients with stage IIb (primary >1 cm, node negative) disease who underwent combined treatment had improved disease-free (p = .005) and disease-specific survival (p = .035). Predictors of survival on multivariable analysis were age >70 years (HR 6.19, p < .001), primary tumor size >1 cm (HR 7.55, p < .001), number of nodal metastases divided into none, <or= 2 and >2 (HR 3.71 per stratum, p < .001). When analyzed with age and disease stage, treatment modality trended toward significance as a predictor of disease-specific (p = .081) and overall survival (p = .076). Disease stage was the most powerful independent predictor on Cox regression (HR 5.43 per stratum, p < .001).

CONCLUSIONS

Merkel cell carcinoma is an aggressive cutaneous malignancy. Age and disease stage are the most important predictors of survival. Combined surgery and radiotherapy improves both locoregional control and disease-free survival. Patients with stage II disease appear to derive the greatest benefit from adjuvant radiotherapy, including improved disease specific survival.

Merkel Cell Carcinoma: Assessing the Effect of Wide Local Excision, Lymph Node Dissection, and Radiotherapy on Recurrence and Survival in Early-Stage Disease—Results From a Review of 82 Consecutive Cases Diagnosed Between 1992 and 2004

BACKGROUND

Wide surgical excision, lymph node dissection, and radiotherapy have been used with varying efficacy in the management of early-stage Merkel cell carcinoma.

METHODS

Records of 82 patients with early-stage Merkel cell carcinoma between 1992 and 2004 were reviewed.

RESULTS

Forty-two patients developed a recurrence, and 44 died during the study period. Twenty-nine patients presented with regional lymph node disease, which was independently associated with diminished survival (hazard ratio [HR], 4.08; 95% confidence interval [CI], 1.55-10.75; P = .005). Lymphadenectomy was independently associated with prolonged disease-free survival (median, 28.5 vs. 11.8 months; HR, .46; 95% CI, .22-.94; P = .034) but not overall survival (P = .25). Margin-negative excision of the primary tumor (60 of 73) was not significantly associated with either prolonged disease-free survival (median, 16 vs. 14 months) or overall survival (median, 54 vs. 34 months). Forty-eight patients received radiotherapy: 36 to the primary site and 31 to the regional lymph nodes. Radiotherapy to both sites was associated with a longer median time to first recurrence (primary site, 24.2 vs. 11.8 months; regional lymph nodes, 46.2 vs. 11.3 months) and survival (primary site, 53.9 vs. 45.7 months; regional lymph nodes, 103.1 vs. 34.2 months). Administration of any radiotherapy was significantly associated with a prolonged time to first recurrence (HR, .39; 95% CI, .20-.75; P = .004) and survival (HR, .39; 95% CI, .18-.82; P = .013) on the Cox regression multivariate analyses.

CONCLUSIONS

Adjuvant radiotherapy to the primary site after surgical excision is recommended in early-stage disease. Involved regional lymph nodes should be treated with radiotherapy with or without lymphadenectomy.

Merkel cell carcinoma

Merkel cell carcinoma (MCC) is a rare, aggressive cutaneous cancer that predominately affects elderly Caucasians with fair skin and has a propensity for local recurrence and regional lymph node metastases. A variety of terms have been used to describe this tumor, including trabecular cell carcinoma, neuroendocrine or primary small cell carcinoma of the skin, and anaplastic cancer of the skin. Although the skin lesion is most commonly found on sun-exposed areas of the head and neck or extremities, it can occur on the trunk, genitalia, and perianal region. The median age is 69 years, but it may occur earlier and more frequently in immunosuppressed patients. Patients with MCC frequently present with a nonspecific erythematous or violaceous firm nodule or small plaque that may be surrounded by small satellite tumors. MCC usually arises in the dermis and extends into the subcutis. It may be difficult to accurately diagnose MCC by light microscopy alone and ancillary techniques, including electron microscopy and immunohistochemistry, may be necessary to make a definitive diagnosis. Management of MCC is dependent on stage of the disease and is hampered by its rarity and lack of randomized trials. Nonetheless, for localized disease most guidelines include wide local excision of the primary tumor either alone or with radiation therapy. Sentinel lymph node biopsy can be helpful in staging and prognosis, but its benefit in survival remains to be seen. Systemic chemotherapy, akin to regimens for small cell carcinoma of the lung, may be considered as an adjuvant following surgery or to treat locoregional or distant disease. The prognosis of MCC is variable. Some patients with localized disease have an indolent course and are well controlled with local excision alone. On the other hand, many tumors are aggressive and have a tendency for locoregional recurrence and distant metastases. Such patients have a grim prognosis with a median survival of 9 months. Successful outcomes are most often seen in patients with early diagnosis and complete excision.