Overview of Merkel cell carcinoma and recent advances in research

Parotid gland metastasis in Merkel cell carcinoma of the head and neck: A series of 14 cases

Merkel cell carcinoma (MCC) is a rare cutaneous cancer of neuroendocrine cell origin that occurs frequently on the head and neck. With a high incidence of local recurrence and regional and distant metastasis, it carries a poor prognosis. We performed a retrospective study to determine the prognostic implications of parotid gland metastasis in MCC of the head and neck. Our study population was made up of 14 patients—13 men and 1 woman, aged 62 to 87 years (mean: 75.9)—who underwent a parotidectomy for the diagnosis of MCC over a period of 10 years and 9 months. Ten patients had a primary skin lesion of the head and neck and 4 presented with a parotid mass and an unknown primary. In all, 13 of the 14 patients were found to have parotid involvement—either a direct extension of MCC into the gland or a positive intraparotid lymph node; some patients had both. All patients underwent tumor excision, and 10 underwent neck dissection. Eleven patients received adjuvant radiotherapy; none received adjuvant chemotherapy. Of the 10 patients who underwent a neck dissection, 6 were found to have a cervical lymph node metastasis on pathologic examination. Follow-up ranged from 1.3 to 39.2 months (mean: 12.4). Three patients were lost to follow-up shortly after surgery, although some information was available on 2 of them. At the final follow-up, mortality data were available on 12 patients; of these, 11 had died. The lone survivor was the patient without a parotid metastasis. Among those known to have died, survival ranged from 1.6 to 49.2 months (mean: 16.0). We conclude that parotid metastasis in patients with MCC of the head and neck is associated with a dismal survival rate that is even worse than the poor survival associated with cervical node involvement.

Lymphoscintigraphy for Sentinel Node Mapping in Head and Neck Cancer

The aim of this comprehensive review is to describe and analyze the role of the sentinel node mapping in head and neck cancers. For this purpose, head and neck neoplasms have been categorized in cutaneous malignancies and neoplasms of the upper aerodigestive tract. A concise description of lymphatic drainage will be the "prelude" for each section, as well as the description of the injection techniques, when specific. Concisely, the attention has been focused on detection rate of the sentinel node by lymphoscintigraphy for each cancer, and for those patients in which the sentinel lymph node has been identified, true-positives rates, false-negative rates, and overall accuracy has been pointed out. Overall, in cutaneous neoplasms of the head and neck, the detection rate is higher than 90%, however the false-negative rate is still an issue, in particular in melanoma, inducing the need for newer developments. In fact, new tracers and techniques are already available, while prospective multicenter trials exploring the outcome impact are needed in the near future. For the upper aerodigestive tract and in particular oral cavity and oropharynx, sentinel lymph node identification by lymphoscintigraphy allows avoiding unnecessary neck dissection and/or node irradiation. Even in this case, the main limit remains the risk of false-negative rates. While, for patients affected by laryngeal and hypopharyngeal cancers the data seem very limited and, although the feasibility has been demonstrated, performances of this lymphoscintigraphy still need to be confirmed by multicenter studies.

Soft Tissue Tumors of the Hand. 2. Malignant

Soft tissue tumors of the hand arise from skin, subcutaneous tissue, tendons, nerve, and blood vessels. Many of these lesions occur on other parts of the body; however, the hand remains a unique site because these tumors have symptoms, appearances, treatments, and prognoses that may be quite different than when on other parts of the body. Their characteristics and the severity of symptoms vary markedly depending on the exact location, size, and type of tumor-and many of these tumors can have multiple forms of presentation. Two articles are intended to provide an overview of benign (previous article) and malignant tumors (this article) of the hand. The rarer and more deleterious tumors are discussed in detail while the common tumors and epidermal lesions with which practitioners are familiar are briefly overviewed. At the completion of these review articles, participants should be able to identify and diagnose various benign and malignant hand tumors as well as understand the accepted current treatment of these growths.

Merkel cell tumour of the external ear. Report of a case

Merkel cells carcinoma (MCC) is an uncommon skin lesion, considered a malignancy of the neuroendocrine system, which is found mainly in elderly people. Its incidence is highly correlated with sun exposure or immunodeficiency syndromes. MCC is often an aggressive tumour with high tendency for local recurrence, lymph node involvement and distant metastasis. To our best knowledge 20 cases originated from the auricle have been described, 2 of them arising from external ear canal. The authors report a case of the ear canal characterized by two others synchronous tumours and the occurrence of a malignant high grade lymphoma, in which contribute of the pathologist was essential for a critical review. MCC diagnosis is not always easy for its pathological and clinical features and it should always be considered in presence of lymphoma. A multidisciplinary approach is basic.

Merkel cell carcinoma of the head and neck

Merkel cell carcinoma (MCC) is a rare neuroendocrine neoplasm of the skin. The tumor most frequently affects elderly patients, with a preference for the head and neck. Incidence rates increase with sun exposure and after immunosuppression and organ transplantation. A significant proportion of MCC have been reported to occur in intimate association with malignant epithelial neoplasms. The genetic mechanisms underlying the development and tumor progression of MCC are poorly understood, sharing pathogenetic mechanisms with other neoplasms of neural crest derivation. MCC has a propensity for spreading to regional lymph nodes, either at presentation or as a first site of relapse. Sentinel lymph node positivity is helpful in predicting the risk of recurrence or metastasis in patients with MCC. Complete surgical resection is the mainstay of treatment of the primary tumor. Tumor resections are recommended to include a 2-3-cm tumor-free margin around the primary lesion when possible, but this is often difficult to achieve in the head and neck, where Mohs micrographic surgery has proved to be effective. The role of adjuvant radiation therapy is controversial. The role of adjuvant chemotherapy in diminishing the risk of subsequent systemic recurrence in patients with positive nodes remains undefined. Overall response rates to combination chemotherapy for surgically unresectable distant metastatic disease are generally high, although responses are transient. Overall survival of head and neck MCC at 5 years postoperatively ranks between 40% and 68%. MCC has a high incidence of locoregional recurrences, but even after a locoregional failure, a substantial proportion of patients achieve long-term disease-free survival. Finally, factors generally associated with survival are the stage of disease at presentation, distant recurrence usually being the most adverse predictor of survival.