Merkel cell carcinoma (MCC) is a rare neuroendocrine tumor of the skin initially believed to arise from the Merkel cells. In the community setting a general radiation oncologist may only encounter this pathology in a handful of cases over the course of their career. Due to the low incidence of this malignancy, few prospective randomized controlled trials have ever been conducted and therefore guidelines are based on relatively lower levels of evidence upon which the clinical recommendations are made. We discuss the case of a female in her 90s presenting with a classic MCC primary lesion, as well as satellite lesions proximal to both the primary and the draining regional lymph nodes with no evidence of nodal involvement. Here we discuss the presentation, management, treatment planning, underlying pathology, results and sequelae of treatment. We also review new treatment modalities, and the most current staging systems and guidelines.
Carcinoma, Merkel Cell ; Female ; Hand ; Humans ; Incidence ; Lymph Nodes ; Merkel Cells ; Neuroendocrine Tumors ; Pathology ; Prospective Studies ; Skin

Carcinoma, Merkel Cell/pathology* ; Humans ; Skin Neoplasms/pathology* ; Tongue ; Tongue Diseases

Carcinoma, Merkel Cell ; pathology ; Humans ; Male ; Middle Aged ; Neoplasm Recurrence, Local ; Skin Neoplasms ; pathology

Aged ; Carcinoma, Merkel Cell ; pathology ; physiopathology ; Female ; Humans ; Lymphatic Metastasis ; Neoplasm Metastasis ; physiopathology

Carcinoma, Merkel Cell ; Ear Canal ; pathology ; Ear Neoplasms ; Humans ; Male ; Middle Aged

BACKGROUND: Merkel cell carcinoma (MCC) is an increasingly common neuroendocrine cancer of the skin. Merkel cell polyomavirus (MCPyV) is one of the causative agents of MCC. The prevalence of MCPyV in primary MCC and sun-exposed non-MCC tumors has been known to have different results depending on where it was investigated. OBJECTIVE: This study assesses the prevalence of MCPyV from primary MCC and sun-exposed non-MCC tumors in Korea. METHODS: A molecular pathology study was performed on 7 tissue specimens of MCC, 1 tissue specimen of metastatic small cell carcinoma of the lung, and 32 tissue specimens of non-MCC tumors occurring from sun-exposed areas [8 basal cell carcinomas (BCCs), 8 squamous cell carcinomas (SCCs), 8 actinic keratoses (AKs), and 8 seborrheic keratoses (SKs)]. All specimens were analyzed to determine the presence of MCPyV-DNA using both polymerase chain reaction (PCR) and real-time quantitative PCR. Immunohistochemistry with monoclonal antibody of MCPyV large T antigen (CM2B4) was also conducted. RESULTS: Using both PCR, MCPyV sequences were detected in six of seven MCC tissue specimens (85.7%). Five (71%) of seven MCC tumors were immunoreactive for CM2B4. All five immunoreactive cases were positive for MCPyV. However, there was no association of MCPyV with BCC, SCC, AK, and SK. CONCLUSION: Our results implicate that MCPyV may contribute to the pathogenesis of primary MCC, not of non-MCC skin tumors in Korea, and the persons with MCPyV infection are unusual in Korea compared to other areas.
Antigens, Viral, Tumor ; Carcinoma, Basal Cell ; Carcinoma, Merkel Cell ; Carcinoma, Small Cell ; Carcinoma, Squamous Cell ; Humans ; Immunohistochemistry ; Keratosis, Actinic ; Keratosis, Seborrheic ; Korea ; Lung ; Merkel cell polyomavirus ; Pathology, Molecular ; Polymerase Chain Reaction ; Prevalence ; Skin ; Skin Neoplasms

Aged ; Breast Neoplasms ; metabolism ; pathology ; surgery ; Cadherins ; metabolism ; Carcinoma, Merkel Cell ; metabolism ; pathology ; Carcinoma, Small Cell ; metabolism ; pathology ; surgery ; Diagnosis, Differential ; Female ; Humans ; Lymphoma ; metabolism ; pathology ; Melanoma ; metabolism ; pathology ; Phosphopyruvate Hydratase ; metabolism ; Synaptophysin ; metabolism

Merkel cell carcinoma is an unusual skin tumor of neuroendocrine origin. The incidence of tumor in the head and neck region is approximately 50%. Most of these carcinomas occur in the elderly patients. The treatment of choice is wide local excision of the primary lesion and regional lymph nodes followed by irradiation. Local recurrence develops in 26-44% of patients despite treatment, and distant metastasis occurs in one third of all patients. Reported overall five-year survival rates range from 30% to 64%. We report a case of Merkel cell carcinoma on the upper eyelid with parotid lymph node metastasis. The pathology, clinical appearance and management of this rare tumor are discussed.
Aged ; Carcinoma, Merkel Cell* ; Eyelids ; Head ; Humans ; Incidence ; Lymph Nodes* ; Neck ; Neoplasm Metastasis* ; Parotid Gland ; Pathology, Clinical ; Recurrence ; Skin ; Survival Rate

PURPOSE: The incidence of malignancies after an organ transplant has steadily increased along with a significant improvement of the long-term recipient survival. Eighty-seven variable post-transplant malignancies out of 2,140 renal transplantations were encountered at Yonsei University Medical Center. Among them, we recently experienced a Merkel cell carcinoma (MCC), a rare malignancy originates from neuro-endocrine cells. Herein, we report 6 MCC cases in cluding 5 that developed in non-transplant patients. METHODS: The medical records of 6 patients who have been diagnosed with a MCC since 1984 were reviewed. RESULTS: There were four males and two females. The mean age at the time of diagnosis was 57.7 (48-65). Five cases were a primary MCC and one was secondary in nature that was related to long-term immunosuppression after a kidney transplant. The extremities (n=3), the head and the neck (n=2) were the prevalent sites for MCC. Four patients are currently alive after mean follow-up of 33.3 months (2-67). The secondary case was a MCC that developed in a 49 years old male patient 16 years after receiving a living donor renal transplant. He noticed a mass on the antero-lateral side of the left thigh 1 month before admission. The mass was soft, round, red-violet in color and measured 5 cm in diameter. With 5 mm of skin margin, the mass was completely excised and was found to be a MCC. To rule out loco-regional and distant metastasis, thoraco-abdomino-pelvic CT scan was taken which showed no evidence of abnormal images. Considering the aggressive biological nature of the MCC, we radically excised more skin and muscular ascia, but no remnant malignant cells were found by pathology. CONCLUSION: MCC presents as a dermal mass mostly at the head, neck, and the extremities with characteristics of rapid aggressive metastasis and recurrence. Wide excision with a 3 cm margin is recommended in patients without a meta stasis. This is the first report of a MCC after a renal transplantat in Korea.
Academic Medical Centers ; Carcinoma, Merkel Cell* ; Diagnosis ; Extremities ; Female ; Follow-Up Studies ; Head ; Humans ; Immunosuppression ; Incidence ; Kidney ; Kidney Transplantation ; Korea ; Living Donors ; Male ; Medical Records ; Middle Aged ; Neck ; Neoplasm Metastasis ; Pathology ; Recurrence ; Skin ; Thigh ; Tomography, X-Ray Computed ; Transplants

OBJECTIVETo investigate the epidemiology, diagnosis, and treatment status of neuroendocrine tumors (NETs) in our hospital.

METHODSMedical records of 252 patients with neuroendocrine tumors diagnosed and treated in our hospital from January 1, 2004 to December 31, 2009 were collected and retrospectively reviewed in this study. The clinicopathological data including age of onset, initial symptoms, primary site, pathological conditions (Sny, CgA, Ki-67), disease stage at diagnosis, treatment, and follow up were analyzed.

RESULTSThe gender ratio M/F of the 252 cases was 1.9:1, with mean age of 55.2 years, and the high incidence was in age of 60-69 years. The tumors were located in the gastrointestinal tract (117 cases, 46.4%), broncho-pulmonary system (74 cases, 29.4%), other sites (61 cases, 24.2%) and unknown primary site (2 cases, 0.8%). Their first clinical symptoms vary, depending on the primary site. The common symptoms of primary rectal NETs were changes in bowel habits (29.3%) and diarrhea or constipation (17.5%), and most gastric NETs presented epigastric discomfort (86.4%). Most patients (71.4%) were diagnosed with stage I, II, III disease. Among the 252 cases, there were 110 carcinoids (43.7%), 108 neuroendocrine carcinomas (42.9%), 23 atypical carcinoids (9.1%), five neuroendocrine tumors (2.0%), four Merkel cell tumors (1.6%), and two composite carcinoids (0.8%). 206 patients (81.7%) received surgery, 39 (15.5%) received chemotherapy, and 31 cases (12.3%) were treated by palliative radiotherapy.

CONCLUSIONSThis single-center retrospective analysis of data demonstrated that males have a higher incidence rate than females. The most common primary sites of NETs are the digestive tract and lungs. The initial symptoms of NETs are different depending on their primary sites. Good prognosis can be achieved in the majority of patients after surgery, chemotherapy and palliative radiotherapy.

Adolescent ; Adult ; Age Factors ; Aged ; Aged, 80 and over ; Antineoplastic Combined Chemotherapy Protocols ; therapeutic use ; Carboplatin ; administration & dosage ; Carcinoid Tumor ; drug therapy ; pathology ; radiotherapy ; surgery ; Carcinoma, Merkel Cell ; drug therapy ; pathology ; radiotherapy ; surgery ; Carcinoma, Neuroendocrine ; drug therapy ; pathology ; radiotherapy ; surgery ; Cisplatin ; administration & dosage ; Digestive System Neoplasms ; drug therapy ; pathology ; radiotherapy ; surgery ; Etoposide ; administration & dosage ; Female ; Fluorouracil ; administration & dosage ; Follow-Up Studies ; Humans ; Lung Neoplasms ; drug therapy ; pathology ; radiotherapy ; surgery ; Male ; Middle Aged ; Neoplasm Staging ; Neuroendocrine Tumors ; drug therapy ; pathology ; radiotherapy ; surgery ; Organoplatinum Compounds ; administration & dosage ; Paclitaxel ; administration & dosage ; Palliative Care ; Retrospective Studies ; Sex Factors ; Survival Rate ; Young Adult