Merkel cell cancer of the skin

An Unusual Complete Response to Immunotherapy in a Locoregional Recurrent Merkel Cell Carcinoma

Merkel cell carcinoma (MCC) is a rare cutaneous neuroendocrine carcinoma. Multimodal treatment is associated with improved locoregional control and survival outcomes. We present the case of an 80-year-old male patient who developed MCC on the left arm. After surgical resection with clear margins and a negative sentinel lymph node biopsy (SLNB), the patient remained under follow-up. Nine months later, local recurrence with left axillary lymph node involvement was diagnosed. An oncologic multidisciplinary team recommended neoadjuvant nivolumab. After completing six cycles of immunotherapy, a radical resection of the tumor on the left upper limb and a complete left axillary lymph node dissection were performed. The final histopathological report showed scar fibrosis with no residual cancer and no lymph node metastasis. MCC exhibits immunological sensitivity, and the use of immune checkpoint inhibitors has revolutionized the treatment of advanced and recurrent disease.

Merkel Cell Carcinoma in an Elderly Male With Extensive Local Disease

Merkel cell carcinoma (MCC) is a rare, highly aggressive neuroendocrine carcinoma of the skin. It is often found in the sun-exposed skin areas of elderly individuals of Caucasian descent. MCC has a tendency for local recurrence and the potential to invade nearby lymph nodes and spread to distant sites in the body. Here, we present the case of an 83-year-old male with a history of multiple comorbidities, including congestive heart failure, obesity, hypertension, benign prostatic hyperplasia, and sarcoidosis, who presented with a slow-growing, fungating lesion on his left lower leg. Histopathological examination revealed MCC with extensive necrosis and involved resection margins. Additional skin lesions on the left knee were confirmed to be MCC. Follow-up CT scans showed lymphadenopathy and a femoral lesion. The patient was deemed a poor candidate for resection and placed on immunotherapy treatment. The low incidence rate and indistinct clinical manifestations of MCC make a conclusive diagnosis dependent on examining histological features and immunohistochemical markers through a lesioned biopsy or resection. Due to the aggressive nature of MCC and the tendency for asymptomatic and painless lesions to escape notice, it is important to raise awareness about this condition. This will lead to earlier detection and intervention, potentially enhancing patient survival rates.

Skin cancer diagnosis based on deep transfer learning and sparrow search algorithm

Skin cancer affects the lives of millions of people every year, as it is considered the most popular form of cancer. In the USA alone, approximately three and a half million people are diagnosed with skin cancer annually. The survival rate diminishes steeply as the skin cancer progresses. Despite this, it is an expensive and difficult procedure to discover this cancer type in the early stages. In this study, a threshold-based automatic approach for skin cancer detection, classification, and segmentation utilizing a meta-heuristic optimizer named sparrow search algorithm (SpaSA) is proposed. Five U-Net models (i.e., U-Net, U-Net++, Attention U-Net, V-net, and Swin U-Net) with different configurations are utilized to perform the segmentation process. Besides this, the meta-heuristic SpaSA optimizer is used to perform the optimization of the hyperparameters using eight pre-trained CNN models (i.e., VGG16, VGG19, MobileNet, MobileNetV2, MobileNetV3Large, MobileNetV3Small, NASNetMobile, and NASNetLarge). The dataset is gathered from five public sources in which two types of datasets are generated (i.e., 2-classes and 10-classes). For the segmentation, concerning the “skin cancer segmentation and classification” dataset, the best reported scores by U-Net++ with DenseNet201 as a backbone architecture are 0.104, $$94.16\%$$ 94.16 % , $$91.39\%$$ 91.39 % , $$99.03\%$$ 99.03 % , $$96.08\%$$ 96.08 % , $$96.41\%$$ 96.41 % , $$77.19\%$$ 77.19 % , $$75.47\%$$ 75.47 % in terms of loss, accuracy, F1-score, AUC, IoU, dice, hinge, and squared hinge, respectively, while for the “PH2” dataset, the best reported scores by the Attention U-Net with DenseNet201 as backbone architecture are 0.137, $$94.75\%$$ 94.75 % , $$92.65\%$$ 92.65 % , $$92.56\%$$ 92.56 % , $$92.74\%$$ 92.74 % , $$96.20\%$$ 96.20 % , $$86.30\%$$ 86.30 % , $$92.65\%$$ 92.65 % , $$69.28\%$$ 69.28 % , and $$68.04\%$$ 68.04 % in terms of loss, accuracy, F1-score, precision, sensitivity, specificity, IoU, dice, hinge, and squared hinge, respectively. For the “ISIC 2019 and 2020 Melanoma” dataset, the best reported overall accuracy from the applied CNN experiments is $$98.27\%$$ 98.27 % by the MobileNet pre-trained model. Similarly, for the “Melanoma Classification (HAM10K)” dataset, the best reported overall accuracy from the applied CNN experiments is $$98.83\%$$ 98.83 % by the MobileNet pre-trained model. For the “skin diseases image” dataset, the best reported overall accuracy from the applied CNN experiments is $$85.87\%$$ 85.87 % by the MobileNetV2 pre-trained model. After computing the results, the suggested approach is compared with 13 related studies.

Merkel cell carcinoma: A systematic review of the demographic and clinical characteristics of 847 cases in Japan

Merkel cell carcinoma (MCC) is a rare but aggressive neuroendocrine carcinoma of the skin associated with Merkel cell polyomavirus and immunosuppression. Although MCC incidence is rising worldwide, MCC has not been sufficiently investigated in Japan. This study aimed to determine MCC demographics in Japan, including incidence, age, sex, location, spontaneous regression, and pure/combined MCC. Using PubMed and Igaku Chuo Zasshi, 847 MCC cases between 1985 and 2015 were extracted, and the main epidemiological characteristics were described. The mean age of all patients was 77.5 years. Regarding the characterized lesions, 63.0% were located on the head and neck, 5.2% on the trunk, 12.6% on the upper limb, 15.1% on the lower limb, 3.5% on the buttocks, and 0.6% on the genitals. Histopathological information regarding the presence of other malignancies could be retrieved in 611 cases, and a coexisting malignancy, mainly squamous cell carcinoma and Bowen's disease, was present in 14.2%. Subcutaneous MCC was observed in 31 patients with a male : female ratio of 1.07 (16 men/15 women). Nodal lesions with unknown primary tumor location were described in 19 patients with a male : female ratio of 0.9 (nine men/10 women) and a mean age of 77.7 years. Of 640 evaluable cases, spontaneous regression developed in 9.1%. Among those 58 patients, the male : female ratio was 1:2.1 in 56 evaluable cases (18 men/38 women). Merkel cell polyomavirus was assessed in 180 patients, and the virus was detected in 31.1% and not detected in 68.9% of the patients. MCC is a rare disease in Japan, with incidence rates and male : female ratios differing from those in the USA and European countries. Besides, this study reveals the high frequency of subcutaneous MCC and MCC with divergent differentiation patterns and spontaneous regression in Japan compared to other countries.

Merkel cell carcinoma: an aggressive cutaneous carcinoma with rare metastasis to the thyroid gland

Merkel cell carcinoma (MCC) is an aggressive and rare neuroendocrine cutaneous carcinoma with poor prognosis and with increasing morbidity and mortality in cases of distant metastasis. Given the rarity of MCC, optimal treatment is not well established. Treatment usually consists of multidisciplinary management with local excision of the primary tumour. Imaging studies are essential for accurate staging and monitoring of disease progression. The incidence of local recurrence is highest in the first 2 years and ranges from 27% to 60%. Distant metastasis is most common in the skin, liver, bone, lung/pleura, brain or distant lymph nodes. The thyroid gland is a rare site of metastasis for MCC with only two case reports published to date. Our patient had a repeat 2-[18F]-fluoro-2-deoxy-d-glucose-postiron emission tomography/CT after the discovery of recurrence of MCC. The high-intensity maximal standardised uptake value of 10.9 in the thyroid isthmus is consistent with malignancy. This case report describes an exceedingly rare thyroid metastasis secondary to MCC.

Merkel Cell Carcinoma of the Digit

Merkel cell carcinoma (MCC) is a biologically aggressive neuroendocrine tumor of the skin. There are roughly 1500 new cases of MCC diagnosed every year in the United States, with an increased incidence over the past 15 years reaching up to 8%. Epidemiological studies show that the highest MCC incidence is seen in men older than 65 years, with a ratio of 0.23 per 10,000 among whites. Merkel cell carcinoma of the skin most commonly presents as a single, rapidly growing, flesh-colored, painless mass. Because MCC is uncommon, histopathological examination is usually delayed. Because of the high mortality rate associated with this aggressive tumor, a multidisciplinary panel is recommended to ensure high-quality coordinated care. The choice of treatment option depends on disease characteristics, staging at presentation, regional lymph node involvement, comorbidities, and performance status of the patient. We report a case of MCC to alert medical professionals of this potentially fatal tumor, as early diagnosis and treatment may improve morbidity and mortality rates.

Recurrent Merkel cell carcinoma of the gluteal region: A case report

Merkel cell carcinoma (MCC) is a rare malignant tumor of the skin. The development of MCC on non-sun-exposed skin is extremely rare, with few cases reported in the literature. The present authors aimed to highlight the characteristic features and treatment options of this tumor. The present authors present a 50-year-old man who developed MCC on the left gluteal region (non-sun-exposed skin). After surgery with clear margins, adjuvant radiotherapy was given. Three months after radiotherapy, lymphatic recurrence was observed and he was treated with chemotherapy. On follow-up, systemic metastases were found and palliative treatment was planned.

Primary Merkel cell carcinoma of the earlobe in a young healthy man

Merkel cell carcinoma (MCC) is an uncommon neuroendocrine cutaneous tumor with poor prognosis. It has the high rate of recurrence, mortality, regional nodal involvement, and distant metastases. It is difficult to diagnose MCC because of its non-specific clinical findings. It usually occurs on sun-exposed areas of the skin, mostly at head and neck. There is a difference in the incidence and prognosis according to site in the head and neck. However, there is no consented site-specific diagnosis, treatment or follow-up protocol for MCC at the head and neck. We herein report a case of MCC arising in the right earlobe of an otherwise healthy young man who has been diagnosed early, thereby successfully treated. With our closed follow-up, there was no tumor recurrence or complication at 33 months after diagnosis.

Merkel-cell carcinoma of the upper limb

Merkel-cell carcinoma is a rare form of aggressive cutaneous cancer that is associated with a poor prognosis. Despite significant advances, its pathogenesis is still poorly understood, and treatment remains controversial. Timely diagnosis and early management is essential in improving survival rate. We present a case of a 63-year-old patient with a rapidly growing upper limb Merkel-cell carcinoma. It was treated with wide-local excision and adjuvant radiotherapy.

Efficacy of isolated limb perfusion (ILP) in patients with Merkel cell carcinoma (MCC): A multicenter experience

BACKGROUND

Merkel cell carcinoma (MCC) is a rare and potentially aggressive neuroendocrine tumor of the skin, with a propensity for locoregional metastases. In two expert referral centers, isolated limb perfusion (ILP) is used to obtain locoregional control in selected locoregionally advanced MCC patients. This study describes our experience.

METHOD

Patients who underwent ILP for MCC were analyzed. ILP was performed with melphalan and tumor necrosis factor (TNF) combination therapy. Depending on the institution, either a normothermic or a hyperthermic temperature regimen was used. Baseline characteristics, toxicity data, locoregional progression-free survival (LPFS) and overall survival (OS) were assessed.

RESULTS

Four males and 6 females with a median age of 78 years (IQR 61-84 years) were included. Four patients underwent ILP for upper extremity disease and 6 for lower extremity disease. All patients received combination therapy with Melphalan and TNF, one patient with the addition of interferon-gamma. No signs of systemic toxicity were present post-ILP. Severe locoregional toxicity (compartment syndrome) occurred in 1 patient and 1 elderly patient with extensive atherosclerosis had to undergo transfemoral amputation due to critical ischemia. Eight patients could be included for response evaluation. The overall response rate (ORR) was 87.5% with a complete response (CR) rate of 62.5%. Two long-term responses of 53 months and 71 months were observed. Median LPFS was 5 months and median OS was 54 months.

CONCLUSION

ILP shows a high CR rate that can be durable. Therefore, ILP should be considered an effective treatment modality for locally advanced MCC.

Preclinical evaluation of NF-κB-triggered dendritic cells expressing the viral oncogenic driver of Merkel cell carcinoma for therapeutic vaccination

BACKGROUND

Merkel cell carcinoma (MCC) is a rare but very aggressive skin tumor that develops after integration of a truncated form of the large T-antigen (truncLT) of the Merkel cell polyomavirus (MCV) into the host's genome. Therapeutic vaccination with dendritic cells (DCs) loaded with tumor antigens is an active form of immunotherapy, which intends to direct the immune system towards tumors which express the respective vaccination antigens.

METHODS

Cytokine-matured monocyte-derived DCs of healthy donors and MCC patients were electroporated with mRNA encoding the truncLT. To permit major histocompatibility complex (MHC) class II next to class I presentation, we used an RNA construct in which the antigen was fused to a DCLamp sequence in addition to the unmodified antigen. To further improve their immunogenicity, the DCs were additionally activated by co-transfection with the constitutively active nuclear factor (NF)-κB activator caIKK. These DCs were used to stimulate autologous CD8⁺ T-cells or a mixture of CD4⁺ and CD8⁺ T-cells. Then the percentage of T-cells, specific for the truncLT, was quantified by interferon (IFN)γ ELISpot assays.

RESULTS

Both the truncLT and its DCLamp-fusion were detected within the DCs by flow cytometry, albeit the latter required blocking of the proteasome. The transfection with caIKK upregulated maturation markers and induced cytokine production. After 2-3 rounds of stimulation, the T-cells from 11 out of 13 healthy donors recognized the antigen. DCs without caIKK appeared in comparison less potent in inducing such responses. When using cells derived from MCC patients, we could induce responses for 3 out of 5 patients; however, here the caIKK-transfected DCs did not display their superiority.

CONCLUSION

These results show that optimized DCs are able to induce MCV-antigen-specific T-cell responses. Therapeutic vaccination with such transfected DCs could direct the immune system against MCC.

Merkel Cell Carcinoma: rising incidence in the East of England

BACKGROUND

Merkel Cell Carcinoma (MCC) is an infrequent but highly aggressive skin cancer. Five-year survival rates are poor, as there are high rates of metastases at primary diagnoses. Recurrences are also common. There is controversy about actual incidence rates which vary considerably between developed countries with majority populations of fair skin types.

OBJECTIVES

We report the age-standardized incidence rates of MCC for both males and females from the East of England, and use linear regression analyses to estimate numbers of cases for 2020 and 2025 to aid healthcare planning and allocation of resources.

METHODS

All cases of MCC diagnosed histopathologically between 1^st January 2004 and 31^st December 2013 were extracted from the databases of the Eastern Office, National Cancer Registration Service, Public Health England, and the Pathology department of the Norfolk and Norwich University Hospital, which serves as the tertiary referral centre for the region. Age-standardization incidence rate calculations (ASIs) and linear regression analyses were performed.

RESULTS

The ASIs for males and females were 0.70 and 1.08 per 100 000 person-years respectively. The total age-adjusted incidence rate was therefore 1.78 per 100 000 person-years. The ratio of female: male disease was 3:2. The total number of cases for this region over the time period studied was 73. There has been a threefold increase over this period. Estimated cases for this region are 17 in 2020, and 22 in 2025. Estimated UK cases for 2020 are 920, and 1134 in 2025.

CONCLUSIONS

MCC is increasing steadily in the East of England, and has risen threefold over the last 10 years and is similar to the highest reported rates from Western Australia. These data are 12-fold higher than previous UK estimates, and suggest that the incidence rate is also rising in other regions of the UK.

Radiation Therapy is Associated with Improved Outcomes in Merkel Cell Carcinoma

BACKGROUND

Following wide excision of Merkel cell carcinoma (MCC), postoperative radiation therapy (RT) is typically recommended. Controversy remains as to whether RT can be avoided in selected cases, such as those with negative margins. Additionally, there is evidence that RT can influence survival.

METHODS

We included 171 patients treated for non-metastatic MCC from 1994 through 2012 at a single institution. Patients without pathologic nodal evaluation (clinical N0 disease) were excluded to reflect modern treatment practice. The endpoints included local control (LC), locoregional control (LRC), disease-free survival (DFS), overall survival (OS), and disease-specific survival (DSS).

RESULTS

Median follow-up was 33 months. Treatment with RT was associated with improved 3-year LC (91.2 vs. 76.9 %, respectively; p = 0.01), LRC (79.5 vs. 59.1 %; p = 0.004), DFS (57.0 vs. 30.2 %; p < 0.001), and OS (73 vs. 66 %; p = 0.02), and was associated with improved 3-year DSS among node-positive patients (76.2 vs. 48.1 %; p = 0.035), but not node-negative patients (90.1 vs. 80.8 %; p = 0.79). On multivariate analysis, RT was associated with improved LC [hazard ratio (HR) 0.18, 95 % confidence interval (CI) 0.07-0.46; p < 0.001], LRC (HR 0.28, 95 % CI 0.14-0.56; p < 0.001), DFS (HR 0.42, 95 % CI 0.26-0.70; p = 0.001), OS (HR 0.53, 95 % CI 0.31-0.93; p = 0.03), and DSS (HR 0.42, 95 % CI 0.26-0.70; p = 0.001). Patients with negative margins had significant improvements in 3-year LC (90.1 vs. 75.4 %; p < 0.001) with RT. Deaths not attributable to MCC were relatively evenly distributed between the RT and no RT groups (28.5 and 29.3 % of patients, respectively).

CONCLUSIONS

RT for MCC was associated with improved LRC and survival. RT appeared to be beneficial regardless of margin status.

Roles for miR-375 in Neuroendocrine Differentiation and Tumor Suppression via Notch Pathway Suppression in Merkel Cell Carcinoma

Dysfunction of key miRNA pathways regulating basic cellular processes is a common driver of many cancers. However, the biological roles and/or clinical applications of such pathways in Merkel cell carcinoma (MCC), a rare but lethal cutaneous neuroendocrine (NE) malignancy, have yet to be determined. Previous work has established that miR-375 is highly expressed in MCC tumors, but its biological role in MCC remains unknown. Herein, we show that elevated miR-375 expression is a specific feature of well-differentiated MCC cell lines that express NE markers. In contrast, miR-375 is strikingly down-regulated in highly aggressive, undifferentiated MCC cell lines. Enforced miR-375 expression in these cells induced NE differentiation, and opposed cancer cell viability, migration, invasion, and survival, pointing to tumor-suppressive roles for miR-375. Mechanistically, miR-375-driven phenotypes were caused by the direct post-transcriptional repression of multiple Notch pathway proteins (Notch2 and RBPJ) linked to cancer and regulation of cell fate. Thus, we detail a novel molecular axis linking tumor-suppressive miR-375 and Notch with NE differentiation and cancer cell behavior in MCC. Our findings identify miR-375 as a putative regulator of NE differentiation, provide insight into the cell of origin of MCC, and suggest that miR-375 silencing may promote aggressive cancer cell behavior through Notch disinhibition.

Merkel cell carcinoma of right buttock in an elderly patient: a case report

Merkel cell carcinoma is a rare primary cutaneous tumor. So far, few cases have been reported.  Herewith we report a case of an 87-years-old male with painless, ulceroproliferative growth measuring 6x6 cm, over right upper outer quadrant of buttock; stage IIB (TNM, T3cNoMo). Patient received neo-adjuvant chemotherapy, injection of carboplatin 420 mg (day one) and etoposide 140 mg (day one to three) three weekly for three cycles followed external beam radiotherapy by Cobalt 60. At three months post-treatment follow-up, clinically no evidence of residual disease or recurrences noted. The purpose of reporting this case was to emphasize to its rarity, early asymptomatic clinical course leading to possibility of delayed diagnosis and paramount importance of high index of clinical suspicion in definitive diagnosis for better treatment result.

Cytological and Immunocytochemical Features of Merkel Cell Carcinoma on Fine Needle Cytology Samples: A Study of 22 Cases

Merkel cell carcinoma (MCC) is an uncommon neuroendocrine small cell tumor derived from the transformation of the homonymous cells in the basal layer of the epidermis. MCC has a generally aggressive course, with a high tendency for local recurrence, lymph node involvement, and distant metastasis. Fine needle cytology (FNC) and immunocytochemistry were used as diagnostic procedures for 22 cases of MCC presented at our institute. All cases of MCC were successfully diagnosed on FNC. Among all of the monoclonal antisera used (CD56, CK20, CK MNF116, neuron-specific enolase (NSE), synaptophysin, and chromogranin), NSE and CD56 showed the highest frequency of positivity. The accuracy of the cytological diagnosis was 100% compared to the corresponding previous or subsequent pathological diagnoses. FNC and immunocytochemistry represent excellent and accurate diagnostic methods to distinguish MCC from other small-cell malignant entities.

Risk of second cancers in merkel cell carcinoma: a meta-analysis of population based cohort studies

The risk of second cancers in Merkel cell carcinoma (MCC) remains uncertain since risk estimates vary worldwide. The global MCC population is growing and there is a demand for better knowledge of prognosis of this disease. The Cochrane Database of Systematic Reviews, MEDLINE, and EMBASE search engines were searched for the relevant literature between January 1999 and September 2014 by use of explicit search criteria. The main outcome was second malignancies associated with MCC patients measured by standardized incidence ratios (SIRs) or other estimates of risks. Five papers fulfilled the inclusion criteria and reported SIRs of second cancer in MCC which varied from 1.07 to 2.80. Performing meta-analysis using random effects model revealed that there was an increased risk for second malignancies due to MCC (SIR, 1.52; 95% CI, 1.10–2.11). There was a significant increase in risk for malignant melanoma (SIR, 3.09; 95% CI, 2.02–4.73) as compared to all common second malignancies among the studies. Updated knowledge about risk of second malignancies in MCC will help in better assessment of the disease prognosis and will help in optimizing the medical and surgical treatment, radiotherapy, follow-up, and surveillance procedures.

Merkel cell carcinoma with partial B-cell blastic immunophenotype: a potential mimic of cutaneous richter transformation in a patient with chronic lymphocytic lymphoma

Merkel cell polyomavirus (MCPyV) is a DNA virus whose pathogenic mechanisms in Merkel cell carcinoma (MCC) are still being unraveled. Emerging reports of an association between MCPyV and chronic lymphocytic lymphoma (CLL) have begun to broaden our understanding of the oncogenic mechanisms of this virus and the known association between these 2 malignancies. Herein, we report a case of MCC demonstrating a B-cell immunophenotype arising in a patient with CLL being treated with rituximab. In this context, we discuss the differential diagnostic considerations, especially with cutaneous Richter transformation (diffuse large B-cell lymphoma). We also assessed for the presence of MCPyV in both the patient's MCC and the CLL. Finally, we provide a large meta-analysis of patients with CLL and MCC. Patients with both MCC and CLL have a dismal prognosis, with greater than 50% overall mortality within the first year and a half after MCC diagnosis.

[Unusual cause of orbital mass]

CASE REPORT

A 54-year-old female presented with a progressive swelling of the upper eyelid since 6 months. Magnetic resonance imaging (MRI) showed an extraconal supratemporal orbital lesion. After resection the histopathological diagnosis confirmed a Merkel cell carcinoma in the lacrimal gland.

CLINICAL COURSE

Due to an incomplete resection the patient underwent adjuvant radiochemotherapy and is relapse-free for 1.5 years.

CONCLUSION

Merkel cell carcinoma (MCC) is a rare neuroendocrine tumor, usually occurring on sun-exposed skin and in 10% in the region of the eyelids. The occurrence of MCC in the lacrimal gland is even less common with only two published cases.

Pink lesions

Dermoscopy (dermatoscopy or surface microscopy) is an ancillary dermatologic tool that in experienced hands can improve the accuracy of diagnosis of a variety of benign and malignant pigmented skin tumors. The early and more accurate diagnosis of nonpigmented, or pink, tumors can also be assisted by dermoscopy. This review focuses on the dermoscopic diagnosis of pink lesions, with emphasis on blood vessel morphology and pattern. A 3-step algorithm is presented, which facilitates the timely and more accurate diagnosis of pink tumors and subsequently guides the management for such lesions.

Merkel cell carcinoma: case study and literature review

Merkel cell carcinoma is a rare, aggressive, highly metastatic, often fatal, primary neuroendocrine tumor typically located on sun-exposed skin. It is frequently found in white males aged 60 to 70 years. The somewhat typical benign clinical appearance of the lesion can result in a delayed diagnosis, leading to a less than optimal outcome.

High-affinity Rb binding, p53 inhibition, subcellular localization, and transformation by wild-type or tumor-derived shortened Merkel cell polyomavirus large T antigens

Interference with tumor suppressor pathways by polyomavirus-encoded tumor antigens (T-Ags) can result in transformation. Consequently, it is thought that T-Ags encoded by Merkel cell polyomavirus (MCPyV), a virus integrated in ∼90% of all Merkel cell carcinoma (MCC) cases, are major contributors to tumorigenesis. The MCPyV large T-Ag (LT-Ag) has preserved the key functional domains present in all family members but has also acquired unique regions that flank the LxCxE motif. As these regions may mediate unique functions, or may modulate those shared with T-Ags of other polyomaviruses, functional studies of MCPyV T-Ags are required. Here, we have performed a comparative study of full-length or MCC-derived truncated LT-Ags with regard to their biochemical characteristics, their ability to bind to retinoblastoma (Rb) and p53 proteins, and their transforming potential. We provide evidence that full-length MCPyV LT-Ag may not directly bind to p53 but nevertheless can significantly reduce p53-dependent transcription in reporter assays. Although early region expression constructs harboring either full-length or MCC-derived truncated LT-Ag genes can transform primary baby rat kidney cells, truncated LT-Ags do not bind to p53 or reduce p53-dependent transcription. Interestingly, shortened LT-Ags exhibit a very high binding affinity for Rb, as shown by coimmunoprecipitation and in vitro binding studies. Additionally, we show that truncated MCPyV LT-Ag proteins are expressed at higher levels than those for the wild-type protein and are able to partially relocalize Rb to the cytoplasm, indicating that truncated LT proteins may have gained additional features that distinguish them from the full-length protein.

IMPORTANCE

MCPyV is one of the 12 known polyomaviruses that naturally infect humans. Among these, it is of particular interest since it is the only human polyomavirus known to be involved in tumorigenesis. MCPyV is thought to be causally linked to MCC, a rare skin tumor. In these tumors, viral DNA is monoclonally integrated into the genome of the tumor cells in up to 90% of all MCC cases, and the integrated MCV genomes, furthermore, harbor signature mutations in the so-called early region that selectively abrogate viral replication while preserving cell cycle deregulating functions of the virus. This study describes comparative studies of early region T-Ag protein characteristics, their ability to bind to Rb and p53, and their transforming potential.

Electrochemotherapy as a new therapeutic strategy in advanced Merkel cell carcinoma of head and neck region

Background

Merkel Cell Carcinoma (MCC) is a rare and aggressive tumour, arising from a cutaneous mechanoceptor cell located in the basal layer of epidermis, with poor prognosis. The treatment of choice for the initial stage of the disease is surgery and/or radiotherapy. The treatment of recurrent or advanced disease is still controversial.

Case report

We report a case of 84 years old woman with a recurrent MCC of the chin treated with electrochemotherapy (ECT). During the period of 20 months, four sessions of ECT were employed, which resulted in an objective response of the tumour and good quality of residual life.

Conclusions

Our case shows the effectiveness of ECT in the treatment of locally advanced MCC of the head and neck region in a patient not suitable for standard therapeutic options.

Merkel cell carcinoma

Merkel cell carcinoma (MCC) is a rare, clinically aggressive cutaneous neuroendocrine neoplasm with a high mortality rate. Though the etiology is not precisely known, Merkel cell polyomavirus DNA has been found recently in a large percentage of MCC tumors. Other suggested risk factors include sun exposure, immunosuppression, and a history of prior malignancy. Work up of patients with MCC most notably includes nodal staging via clinical examination or sentinel lymph node biopsy. The prognosis for most patients with MCC is poor, and the rarity of MCC precludes the prospective, randomized clinical trials necessary to elucidate optimum treatment protocols. Most published data support the use of a multimodality approach centered around surgical excision with negative margins, sentinel lymph node biopsy to establish the presence or absence of nodal metastases, adjuvant radiothearpy to decrease the risk of recurrence, and systemic chemotherapy in the case of widespread disease.

Merkel cell carcinoma of left groin: a case report and literature review

Merkel cell carcinoma (MCC) is an uncommon highly aggressive skin malignancy with an increased tendency to recur locally, invade regional lymph nodes, and metastasize distally to lung, liver, brain, bone, and skin. The sun-exposed skin of head and neck is the most frequent site of involvement (55%). We report the case of a 63-year-old Caucasian male patient who presented with a recurrent left inguinal mass for the third time after surgical resection with safe margins and no postoperative radio- or chemotherapy. The presented mass was excised, and pathological diagnosis revealed recurrent MCC. The patient underwent postoperative radiation therapy, and 6 months later, he developed a right groin mass which was resected and pathological diagnosis confirmed metastatic MCC. Six months later, patient developed an oropharyngeal mass which was unresectable, and pathological biopsy confirmed metastatic MCC. Patient was offered palliative radio- and chemotherapy. In this paper, we also present a brief literature review on MCC.

A practical update of surgical management of merkel cell carcinoma of the skin

The role of surgeons in the treatment of Merkel cell carcinoma (MCC) of the skin is reviewed, with respect to diagnosis and treatment. Most of the data in the literature are case reports. Surgery is the mainstay of treatment. A wide local excision, with sentinel node (SLN) biopsy, is the recommended treatment of choice. If SLN is involved, nodal dissection should be performed; unless patient is unfit, then regional radiotherapy can be given. Surgeons should always refer patients for assessment of the need for adjuvant treatments. Adjuvant radiotherapy is well tolerated and effective to minimize recurrence. Adjuvant chemotherapy may be considered for selected node-positive patients, as per National Comprehensive Cancer Network guideline. Data are insufficient to assess whether adjuvant chemotherapy improves survival. Recurrent disease should be treated by complete surgical resection if possible, followed by radiotherapy and possibly chemotherapy. Generally results of multimodality treatment for recurrent disease are better than lesser treatments. Future research should focus on newer chemotherapy and molecular targeted agents in the adjuvant setting and for gross disease.

Radiotherapy is associated with significant improvement in local and regional control in Merkel cell carcinoma

Introduction

Merkel cell carcinoma (MCC) is a rare tumour of skin. This study is a retrospective audit of patients with MCC from St Vincent’s and Mater Hospital, Sydney, Australia. The aim of this study was to investigate the influence of radiotherapy (RT) on the local and regional control of MCC lesions and survival of patients with MCC.

Method

The data bases in anatomical pathology, RT and surgery. We searched for patients having a diagnosis of MCC between 1996 and 2007. Patient, tumour and treatment characteristics were collected and analysed. Univariate survival analysis of categorical variables was conducted with the Kaplan-Meier method together with the Log-Rank test for statistical significance. Continuous variables were assessed using the Cox regression method. Multivariate analysis was performed for significant univariate results.

Results

Sixty seven patients were found. Sixty two who were stage I-III and were treated with radical intent were analysed. 68% were male. The median age was 74 years. Forty-two cases (68%) were stage I or II, and 20 cases (32%) were stage III. For the subset of 42 stage I and II patients, those that had RT to their primary site had a 2-year local recurrence free survival of 89% compared with 36% for patients not receiving RT (p<0.001). The cumulative 2-year regional recurrence free survival for patients having adjuvant regional RT was 84% compared with 43% for patients not receiving this treatment (p<0.001). Immune status at initial surgery was a significant predictor for OS and MCCSS. In a multivariate analysis combining macroscopic size (mm) and immune status at initial surgery, only immune status remained a significant predictor of overall survival (HR=2.096, 95% CI: 1.002-4.385, p=0.049).

Conclusions

RT is associated with significant improvement in local and regional control in Merkel cell carcinoma. Immunosuppression is an important factor in overall survival.

Advances in Merkel cell carcinoma pathogenesis and management: a recently discovered virus, a new international consensus staging system and new diagnostic codes

Merkel cell carcinoma is a rare but aggressive neuroendocrine carcinoma of the skin with a rising incidence and a high mortality rate. It occurs primarily in sun-exposed skin of older individuals. It is characterized by a high rate of local recurrence, regional lymph node metastases and distant metastases, occurring even after prompt treatment. Many controversies exist regarding its pathogenesis and optimal management. The discovery of Merkel cell polyomavirus has been a major breakthrough in understanding the aetiology of the disease. A recently adopted new international consensus staging system in combination with new international diagnostic codes are expected to facilitate future clinical trials and improve the management of patients. According to recent (2010) guidelines, most patients should be managed with a combination of surgery and radiotherapy.

Merkel cell carcinoma in Western Australia: a population-based study of incidence and survival

BACKGROUND

Merkel cell carcinoma (MCC) is an uncommon but aggressive cutaneous skin cancer. Even with the appropriate treatment, MCC is prone to recurrence, and metastases are common. Exposure to ultraviolet radiation has been suggested as contributing towards the development of MCC. MCC has not been extensively investigated in Australia, even though Australia has the highest incidence of sun-related cancers in the world.

OBJECTIVES

To describe the demographics and determine trends of incidence and survival of MCC cases in Western Australia (WA).

METHODS

All reported invasive cases of MCC incident between 1 January 1993 and 31 December 2007 were extracted from the WA Cancer Registry. Age-adjusted incidence rates for MCC were calculated using direct standardization to the U.S. standard 2000 population. Cause-specific survival was investigated using Kaplan-Meier and Cox proportional hazards analysis. results: Two hundred and fifteen cases were confirmed by pathological review as being definite cases of MCC. Patients were mainly males (65%) and elderly (median age 77 years). Standardized age-adjusted incidence rates were higher in men (1·0/100,000) than in women (0·63/100,000) and higher in older ages (15·5/100,000 in the 85+year age group) than younger ages (0·1/100,000 in the 30-34 year age group). Five-year cause-specific survival was 64%.

CONCLUSIONS

Incidence of MCC in WA is the highest reported in the literature. In addition, MCC has worse survival than melanoma. The high rates and demographic and anatomical distribution are consistent with sun exposure playing a causal role.

Human polyomaviruses in skin diseases

Polyomaviruses are a family of small, nonenveloped viruses with a circular double-stranded DNA genome of ∼5,000 base pairs protected by an icosahedral protein structure. So far, members of this family have been identified in birds and mammals. Until 2006, BK virus (BKV), JC virus (JCV), and simian virus 40 (SV40) were the only polyomaviruses known to circulate in the human population. Their occurrence in individuals was mainly confirmed by PCR and the presence of virus-specific antibodies. Using the same methods, lymphotropic polyomavirus, originally isolated in monkeys, was recently shown to be present in healthy individuals although with much lower incidence than BKV, JCV, and SV40. The use of advanced high-throughput sequencing and improved rolling circle amplification techniques have identified the novel human polyomaviruses KI, WU, Merkel cell polyomavirus, HPyV6, HPyV7, trichodysplasia spinulosa-associated polyomavirus, and HPyV9. The skin tropism of human polyomaviruses and their dermatopathologic potentials are the focus of this paper.

Merkel cell carcinoma metastatic to the thyroid gland: Aspiration findings and differential diagnosis

Clinically diagnosed metastasis to the thyroid gland is exceptionally rare and may present diagnostic issues on fine needle aspiration. The most common primary sites of metastases to the thyroid are cancers of the lung, breast, skin (especially melanoma), colon, and kidney. Herein, we report a case of metastatic Merkel cell carcinoma to the thyroid presenting as a 2.1-cm solid nodule in a 50-year-old male with a previous history of Merkel cell carcinoma of the upper extremity. The aspirates were moderately to highly cellular featuring small to intermediate sized cells with scant to no cytoplasm, round-to-oval nuclei with finely dispersed chromatin, and predominantly arranged as scattered single cells. There was focal nuclear molding, numerous mitoses, and karyorrhectic nuclei. The differential diagnosis centered on the "small round blue cell" tumor group such as medullary thyroid carcinoma and non-Hodgkin lymphoma. However, in light of our patient's previous history, the FNA findings were most consistent with a metastasis of Merkel cell carcinoma. In patients with a known history of a primary neoplasm, the differential diagnosis of a thyroid nodule should always include potential metastasis.

A review of the epidemiology and treatment of Merkel cell carcinoma

Merkel cell carcinoma is a very rare and aggressive neoplasm. Due to its rarity, therapeutic guidelines are not well established, especially for regionally advanced disease. Articles in English, French, Italian, Portuguese, and Spanish from the last 20 years were identified in MEDLINE and reviewed. The key word "Merkel" was used for the search, relevant articles were selected, and their references were examined. The most important articles related to epidemiology, genesis and treatment were reviewed. The incidence of Merkel cell carcinoma is increasing due to the advancing age of the population, higher rates of sun exposure and an increasing number of immunocompromised individuals. With regard to etiology, the recently described Merkel Cell polyomavirus is thought to play a role. Either local or regional surgical intervention remains the standard of care, but adjuvant radiotherapy or radiotherapy as a primary treatment have been discussed as reasonable therapeutic options. An update on this rare neoplasia is essential because of its increasing incidence and changing treatment options.

Merkel cell carcinoma

Merkel cell carcinoma is a rare, highly aggressive neuroendocrine cutaneous neoplasm with a variable clinical presentation. Histologically, it is a predominantly dermal-based lesion composed of monotonous small round cells with scanty cytoplasm, often difficult to differentiate from small round cell tumors, metastatic small cell carcinoma, blastic hematologic malignancies, and melanoma. The malignant cells express both epithelial and neuroendocrine immunohistochemical markers, a unique feature that helps differentiate this neoplasm from other entities. The pathogenesis of Merkel cell carcinoma has remained a mystery despite its association with various chromosomal abnormalities and with growth signaling and apoptotic pathways. The discovery of the Merkel cell polyomavirus suggests another clue to its pathogenesis. This virus integrates into band 3p14 and promotes carcinogenesis by altering the activity of tumor suppressor and cell cycle regulatory proteins. This discovery of the Merkel cell polyomavirus may greatly enhance our understanding of this rare aggressive neoplasm and allow further advancements in treatment.

Primary merkel cell carcinoma clinically presenting as deep oedematous mass of the groin

Merkel cell carcinoma (MCC) is a relatively rare, polyomavirus associated, primary neuroendocrine carcinoma of the skin which is usually arising from dermal skin layers. However, the origin of MCC in the subcutaneous tissue is debatable. We report a 58-yearold female patient with an oedematous mass on her left groin that was firm in consistency and had no discoloration or other visible abnormality of the overlying skin. On histology and immunohistology the tumour was consistent with the diagnosis of MCC showing a predominant subcutanous growth pattern. Pelvic magnetic resonance tomography revealed a tumour conglomerate reaching from the subcutis of the left groin to the left paraaortal and parailiacal region indicating widespread lymphogenic metastisation. Despite complete medical work-up no other MCC primary could be detected. In conclusion, predominant subcutaneous growth pattern as well as tumour localization in the groin are uncommon features of MCC. MCC showing the aforementioned features may be associated with significant delay of diagnosis and therefore represents an unfavourable prognostic factor.

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.