Merkel cell carcinoma of the lower leg with retroperitoneal GIST: a very rare association

Merkel cell carcinoma (MCC) is a rare neuroendocrine tumor of the skin. Although its association with other malignancies is well known, an association with gastrointestinal stromal tumor (GIST) has yet not been described.We report about a 65-year-old female patient who presented with a hypervascularized subcutaneous tumor mass of her left calf. Resection of the primary tumor and histopathological investigations confirmed the diagnosis of MCC. The patient was treated by delayed Mohs surgery, and tumor-free margins were obtained. Sentinel lymph node biopsy was negative for metastatic spread. Primary tumor and lymph node basin were treated by adjuvant radiotherapy. During staging of the patient, a second malignancy-a GIST-was detected. Neoadjuvant treatment with multikinase inhibitor imatinib induced a partial response of GIST that was eventually removed by surgery. However, 8 months later, the patient developed subcutaneous regional metastases of MCC, which were surgically removed. Adjuvant therapy was planned by oncologists.To the best of our knowledge, the occurrence of MCC and GIST in the same patient has yet not been reported. In contrast to GIST, MCC did not respond to imatinib, although c-kit mutations are common in MCC.

[Merkel cell carcinoma of the ear lobe complicated with nephrosis syndrome and malignant lymphoma: a case report]

Here we report a rare case of Merkel cell carcinoma complicated with nephrosis and malignant lymphoma. A 79-year-old male, who had undergone rectectomy due to colorectal cancer about 10 years previously, was diagnosed as Merkel cell carcinoma of the left ear lobe with lymph node metastases. Tumor resection and lymph node dissection were performed. A year later, follow-up PET-CT revealed a small hot spot at the ileocecum without apparent tumor formation based on examination by colonoscopy. The patient received 56 Gy of radiation. Two months later, he developed new-onset nephrosis followed by renal failure, and was referred to our hospital (Cr 4.26 mg/dL, UA 13.5 mg/dL, Alb 2.1 g/dL). Further examination negated the possibility of vasculitis, collagen disease, or myeloma kidney. Since his renal function continued to decline, causing uremic symptoms, he was hospitalized and underwent hemodialysis soon after referral. Abdominal CT scan revealed an ileocecal mass with multiple abdominal lymphadenopathy, which was later diagnosed as diffuse large B-cell lymphoma (stage IV) by tumor biopsy. Corticosteroid therapy (prednisolone 60 mg/day) was soon initiated with no response. Local skin redness and blister formation at the left shoulder emerged gradually, which strongly suggested a local recurrence of Merkel cell carcinoma. Despite the use of rituximab, the patient's general condition deteriorated without any sign of recovery. Three months after the start of dialysis, we discontinued dialysis therapy due to his poor health status, and eventually he died of cachexia. Autopsy revealed triple cancers: rectal cancer, Merkel cell carcinoma, and malignant lymphoma. In addition to the case report, we will summarize and discuss former similar case reports in the literature.

[Merkel cell carcinoma in patient after organ transplantation]

Merkel cell carcinoma (MCC) is a rare, neuroendocrine tumour of the skin characterized by a very aggressive course. Firm, red-to-purple, typically non tender papules or nodules is a common of it's clinical manifestation. This carcinoma is more common among white Caucasians males in advanced age. The important risk factors for MCC are immunodeficiency or immunosuppression in patients after organ transplantation. MCC observed in organ recipients is associated with especially rapid progression as compared with general population and tendency to metastasis. Surgical excision of primary tumour with adequate margins and sentinel lymph node dissection with adjuvant radiotherapy improves regional control of disease and patients survival. Chemotherapy is usually used as a palliative treatment for advanced forms of the disease.

[Merkel cell carcinoma]

Merkel cell tumor is a highly aggressive cancer of the skin and mucous membranes. It is most common in elderly patients and in individuals with impaired immunity. Merkel Cell Carcinoma can develop anywhere, but it most frequently affects the heac and neck, as well the skin of the upper limbs. Clinically, it occurs as red, glistening tumor with telangiectasias on the surface At the moment of diagnosis, 50% of patients have already developed metastases, most commonly to regional lymph nodes. The treatment depends on the severity and consists primarily of surgical excision with a margin of healthy tissue followec by possible complementary radiotherapy. Chemotherapy is introduced in advanced cases.

Merkel cell carcinoma, version 1.2014

Merkel cell carcinoma is a rare, aggressive cutaneous tumor that combines the local recurrence rates of infiltrative nonmelanoma skin cancer with the regional and distant metastatic rates of thick melanoma. The NCCN Guidelines for Merkel Cell Carcinoma provide recommendations on the diagnosis and management of this aggressive disease based on clinical evidence and expert consensus. This version includes revisions regarding the use of PET/CT imaging and the addition of a new section on the principles of pathology to provide guidance on the analysis, interpretation, and reporting of pathology results.

Milestones in the staging, classification, and biology of Merkel cell carcinoma

Merkel cell carcinoma (MCC) is an aggressive skin cancer that is causally associated with ultraviolet light exposure and a recently discovered polyomavirus. Before 2010, MCC was staged using any of 5 unique systems in active use. In 2010, a consensus staging system for MCC was adopted worldwide and replaced these systems. This consensus system includes substages that reflect prognostic differences based on whether nodal evaluation was performed by pathologic analysis or clinical assessment alone. MCC-specific disease classification in ICD-9, to be expanded in the upcoming ICD-10, has improved the ability to track and manage this malignancy. Several biomarkers and histopathologic features have been identified that improve understanding of this cancer and may lead to future refinement of the current staging system. In 2008, the Merkel cell polyomavirus was discovered and is now thought to be a critical mechanism of transformation in at least 80% of MCCs. In patients who produce antibodies to the viral T-antigen oncoprotein, the titer increases and decreases with MCC disease burden and can be a clinically useful marker of recurrence. Diverse studies link CD8-positive T-cell function with outcomes in MCC and serve as the rational basis for ongoing trials of therapies to augment cellular immunity. This article reviews basic and translational research insights that will lead to improved staging, prognostic accuracy, and mechanism-based therapy for this often-lethal skin cancer.

Ultrastructural studies of perichromatin granules with special references to Merkel cell carcinoma

Since it has been convincingly demonstrated that Merkel cell polyomavirus (MCPyV), a new type of virus, isolated in 2008, induces some of Merkel cell carcinoma (MCC), we searched MCPyV in specimens taken from MCC patients by electron microscopy. The purpose of this communication is to report the presence of perichromatin granules (PCGs), which can be misinterpreted as virus-like particles (VLP). Tissues from several cutaneous tumors including MCC were examined by electron microscopy (EM). EM revealed intranuclear and spherical electron-dense particles with halo, approximately 55 nm in diameter suggesting possible VLP. However, granular structures were detected in MCPyV DNA positive and also negative MCC. Moreover, the same structures were detected in the tumor cells of SCC associated with MCC, those of malignant melanoma (MM), schwannoma, and also in the lesional melanocyte, fibroblast, apoptotic cell and mitotic cell. Since MCPyV DNA could not be detected in collision MCC with SCC, MM and schwannoma, this observation could mean that the granular structures we dealt with in this report represent PCGs, but not VLP and show an absence of viral particles in MCC.

Merkel-cell carcinoma: preoperative clinical diagnosis and therapeutic implications

The authors report the personal experience of some patients undergoing surgery for carcinoma of Merkel and discuss the diagnosis and therapeutic approach guided by literature and international guidelines. Merkel cell carcinoma (MCC) is a rare and aggressive neuroendocrine tumour, which prefers the Caucasian race in adulthood. Approximately 78% of patients are over than 59 years, the most common location is at the level of the head and neck (50.8%) and less frequently in the limbs (33.7%). The literature is discordant about the causes and risk factors for this cancer. In fact, some authors describe major risk factor the immunosoppression, still others see prolonged exposition to UV radiation increases the risk for the onset of this tumor. Metastasizes early to the skin (28%), the lymph nodes (27%), liver (13%), lung (10%), bone (10%) and encephalon (6%), and may recur both locally (30-60%) and both locoregional (40-73%). Our experience confirms the difficulty of preoperative clinical diagnosis and a correct therapeutic approach to Merkel cell carcinoma for the lack of specific characteristics as first clinical assessment, which may keep the suspect nature. International guidelines provide a wide excision (3 cm in largeness and 2 cm in depth) to reduce the risk of disease recurrence, preferring adjuvant chemotherapy not radiotherapy. For lesions of stage I-II over the wide excision also regional lymphadenectomy is performed or, more rarely, the technique of sentinel lymph node.

Merkel-Zell-Karzinom

Merkel cell carcinoma (cutaneous neuroendocrine carcinoma) is an uncommon, highly malignant, neuroendocrine skin tumour. Typically, the primary is a fast-growing tough dermal nodule that is characterized histologically by uniform round cells with a small cytoplasmic rim. The tumour cells express the cytokeratins 8, 18, 19, 20, neurofilament, synaptophysin, chromogranin, and neuron-specific enolase. A high frequency of local recurrences (25-77%) and lymph-node metastases (50%) are characteristic features of Merkel cell carcinoma. The 5-year survival rate is 30-74%. Merkel cell carcinomas are highly radiosensitive. Thus, besides surgical methods, radiation should be included into the treatment concept in every stage. We present four cases of Merkel cell carcinoma with different courses for a review-like discussion of this disease giving instructions for rapid diagnosis and effective therapy.

Merkel cell carcinoma

A 92-year-old man presented for evaluation with a 1-month history of a rapidly growing asymptomatic pink nodule on his forearm. Biopsy results of the lesion demonstrated pathology consistent with Merkel cell carcinoma (MCC). Immunohistochemical studies displayed positive cytoplasmic staining for cytokeratin AE1/AE3, positive dot-like perinuclear staining for cytokeratin-20, diffuse cytoplasmic staining for neuron specific enolase, and no significant staining for S-100. Subsequent positron emission tomography did not reveal evidence of metastatic disease. Wide excision of the lesion was performed along with a sentinel node biopsy of his left axilla. The sentinel nodes were negative for MCC. Adjuvant radiation treatment of the tumor site was provided because the pathologist noted MCC within 2 mm of the deep margin.

Collision tumour of the breast composed of Merkel cell carcinoma and invasive ductal carcinoma: a case report

We report a case of a 71-year-old female with a palpable breast mass. Pathologic evaluation of the breast mass showed a unique collision tumour with a high-grade invasive and in-situ ductal carcinoma component and a high-grade neuroendocrine carcinoma component. The neuroendocrine component turned out to be Merkel cell carcinoma (MCC), with immunohistochemical confirmation. To the best of our knowledge, this is the first case report of a collision tumour with ordinary ductal carcinoma and MCC in the breast.

Diagnostic performance of fluorine-18-fluorodeoxyglucose positron emission tomography in patients with Merkel cell carcinoma: a systematic review and meta-analysis

BACKGROUND

Some studies reported the usefulness of fluorine-18-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) and PET/computed tomography (CT) in patients with Merkel cell carcinoma (MCC).

OBJECTIVE

The aim of this study was to systematically review and meta-analyze published data about the diagnostic performance of 18F-FDG PET and PET/CT in patients with MCC.

METHODS

A comprehensive literature search of studies published through June 2013 regarding 18F-FDG PET and PET/CT in patients with MCC was performed. All retrieved studies were reviewed and qualitatively analyzed. Pooled sensitivity, specificity, positive and negative likelihood ratio (LR+ and LR−) and diagnostic odds ratio (DOR) of 18F-FDG PET or PET/CT in patients with MCC on a per examination-based analysis were calculated. The area under the summary receiver operating characteristic (ROC) curve was calculated to measure the accuracy of 18F-FDG PET or PET/CT in these patients.

RESULTS

Ten studies comprising 329 patients (549 scans) with MCC were included in the qualitative analysis (systematic review) and discussed. The quantitative analysis (meta-analysis) of six selected studies (including 92 patients with MCC) provided the following results on a per examination-based analysis: sensitivity was 90 % (95 % CI 80–96), specificity 98 % (95 % CI 90–100), LR+ 12 (95 % CI 4.3–33.0), LR− 0.15 (95 % CI 0.08–0.28), and DOR 86.8 (95 % CI 23–327). The area under the summary ROC curve was 0.96. No significant statistical heterogeneity between the studies was found.

CONCLUSIONS

In patients with MCC, 18F-FDG PET or PET/CT demonstrated high sensitivity and specificity, being accurate methods in this setting. Nevertheless, the literature focusing on the use of PET and PET/CT in MCC still remains limited. Prospective studies are needed to substantiate the high diagnostic accuracy of these methods in MCC.

Primary cutaneous small cell carcinoma; a case report with differential diagnosis

Primary cutaneous small cell carcinoma (PC-SmCC) is extremely rare; only two cases have been reported in the world literatures. A 79-year-old woman presented a small cutaneous tumor in the face. Physical examination showed a tumor measuring 1.0x.08x0.6 cm in the shallow skin of the face. Excisional skin biopsy was performed. The biopsy showed complete excision of the tumor. The tumor was located in the shallow dermis and no connections to epidermis were seen. The tumor was invasive into subcutaneous tissue and surrounding dermis. The tumor was very hypercellular tumor composed of small cells with scant cytoplasm, hyperchromatic nu lei, negative nucleoli, and molded nuclei. The shapes of tumor cells are round, ovoid or spindle. The histological appearances fulfilled the criteria of SmCC of WHO. Immunohistochemically, the tumor cells were positive for cytokeratin (CK) AE1/3, CK CAM5.2, CK34BE12, CD5, CD6, CK8, p63, NSE, NCAM, synaptophysin (focal), chromogranin (focal), p53, KIT, PDGFRA and Ki-67 (labeling index (LI)=86%). They were negative for CK7, CK19, CK20, EMA, vimentin, CEA, S100 protein, CA19-9, TTF-1, MUC1, MUC2, MUC5AC and MUC6. Mucin histochemistry revealed no mucins. A molecular genetic analysis of PCR-direct sequencing identified no mutations of KIT (exons 9, 11, 13, and 17) and PDGFRA (exons 12 and 18) genes. The author diagnosed this cutaneous tumor as SmCC. Post-diagnosis whole body examination using various imaging and endoscopic techniques revealed no tumors. This may confirm that the skin tumor was primary. The cutaneous tumor was completely resected with wide margins. The patient is now followed up without therapy 8 months after the diagnosis. No recurrence or metastasis is seen. The differential diagnosis from Merkel cell carcinoma and basal cell carcinoma is very difficult and herein discussed.

Giant metastatic Merkel cell carcinoma

A 68-year-old man presented with a rapidly growing, asymptomatic mass on his left mid-back for the past 3 months. The patient's medical history revealed an intentional 60-pound weight loss over the previous 2 years along with smoking approximately 1 pack of cigarettes per day. On physical examination, a fungating, 11-cm red tumor with palpable broader underlying extension (23 cm total) was present on the left mid-back with distinct red dermal nodules in a dermatomal distribution. In close proximity were two ulcerated nodules, proven histologically to be basal cell carcinomas. In the left groin was massive, fixed lymphadenopathy. A punch biopsy of the tumor was performed, which showed a dense infiltrate of small, round hyperchromatic blue cells that stained positive for CD 56 and pancytokeratin in a perinuclear dot pattern. Tumor cells were negative for CK20, TTF, CK7, and LCA.

[Merkel cell carcinoma: (r)evolution]

Merkel Cell Carcinoma (CCM) is an aggressive cutaneous tumor of the elderly, which has become the second cause of mortality linked to skin cancer. This has led clinicians and scientists to devote more time to the study of this rare tumor, announcing to a revolution in our understanding, diagnosis and therapy of this cancer. We present here these recent advances, which illustrate the exponential growth of knowledge in the medical field, drawing comparisons with more frequent cancers such as melanoma and squamous cell carcinoma.

Merkel cell carcinoma of the head and neck and associated second primary cancers: report of three cases

Merkel cell carcinoma (MCC) is a rare and aggressive neuroendocrine skin carcinoma. The purpose of this study is to describe clinical and pathological characteristics, diagnostic procedure and treatment outcomes of the patients with MCC of the head and neck treated in Otorhinolaryngology, Head and Neck Surgery Department of the University Hospital Center Zagreb between the years 2007 and 2011. Three patients with MCC of the head and neck were treated during this period. First patient was diagnosed with MCC of the left retroauricular region with metastases in the lymph nodes of the left side of the neck, pT2N2M0 Stage IIIB. Second patient was diagnosed with anaplastic carcinoma of the lower lip, pT1N1bM0 Stage IIIB and third patient was diagnosed with MCC of the face which was previously treated as benign lesion, cT1N1bM0 Stage IIIB. Two of the patients had second primary tumor of different histology. All of the patients were treated with wide surgical excision of the tumor and neck dissection combined with adjuvant radiotherapy. Treatment outcome was poor and reason for this was late detection of disease. Menagment of the MCC patients requires multidisciplinary approach with high clinical suspicion of the treating specialist and pathologist due to immunohistochemical techniques required for diagnosis. Detection of the MCC in earlier stages is necessary for the better survival rate.

Diagnostic biopsy does not commonly induce intratumoral CD8 T cell infiltration in Merkel cell carcinoma

Background

Merkel cell carcinoma is a polyomavirus-associated cancer that is strongly linked with T lymphocyte immune suppression in epidemiologic studies. CD8+ T cell infiltration into MCC tumors (intratumoral) has recently been shown to be strongly predictive of improved survival. In contrast, the presence of CD8+ T cells at the border of the tumor (peritumoral) had no independent prognostic value. Spontaneous regression has been reported for MCC approximately one thousand times more often than would be expected given the frequency of this cancer. Many of these events began shortly after biopsy, and in some cases lymphocytic infiltration was described.

Methodology/Principal Findings

To determine whether CD8+ lymphocyte infiltration in MCC tumors is commonly altered by biopsy.33 MCC patients who had microscopic confirmation of MCC on both an initial biopsy and a re-excision specimen were included in this study. Intratumoral and peritumoral CD8 lymphocyte infiltration was quantitated using immunohistochemistry and compared using the paired t-test in biopsy versus re-excision samples. There was a trend toward increased CD8 infiltration after biopsy in a peritumoral (‘stalled’) pattern (p = 0.08), however, biopsy was not associated with a significant increase in CD8 T cells in the clinically more important intratumoral location (p = 0.58).

Conclusions/Significance

The initial diagnostic biopsy for MCC does not commonly alter intratumoral CD8+ T cell infiltration, suggesting it does not directly induce immunologic recognition of this cancer. Because CD8 infiltration is typically stable after biopsy, this parameter may be useful to assess the efficacy of future immune therapies for this virus-associated, immunogenic, often-lethal cancer.

Merkel cell carcinoma--a rare cause of non-healing skin ulcer: a case report

Merkel cell carcinoma (MCC) is a rare tumour of skin which needs to be differentiated from other small cell tumours like small-cell carcinoma of lung, melanoma, and lymphoma. Definitive diagnosis is made by immunohistochemistry and staining positively with cytokeratin. There is very little data regarding treatment of metastatic MCC and many questions remain unanswered. MCC is a chemosensitive tumour and many different chemotherapeutic regimens have been used alone or in combination with radiotherapy to treat metastatic MCC. Although complete and partial responses are achieved, they are mostly short lived and tumour usually recurs. Here a case is reported who had partial remission with chemotherapy (etoposide and cisplatin) and radiation therapy in a patient with metastatic MCC.

Merkel cell carcinoma in a patient with noninvasive vulvar Paget's disease

We present the first case of inguinal Merkel cell carcinoma of unknown primary origin in a patient with vulvar Paget's disease. Correlation with immune suppression of both entities warrants further investigation. Additionally, this case highlights the value of ultrasound scanning in the detection of inguinal metastasis.

A Merkel cell carcinoma presenting as a solitary lymph node metastasis without a primary lesion. Report of a case and review of the literature

Merkel cell carcinoma is an uncommon, aggressive neuroendocrine tumour of the skin. At presentation regional lymph nodes are involved in approximately one third of the patients. In this report a patient is presented in whom Merkel cell carcinoma presented as a solitary lymph node metastasis with an unknown primary skin lesion. The diagnosis of unknown primary merkel cell carcinoma including the use of immunohistochemical markers and treatment options based on data from the literature are discussed.