2016 Volume 55 Issue 4 Pages 256-262
Background : Merkel cell carcinoma (MCC) is considered to be a rare neuroendocrine tumor originating from the Merkel cell of the skin. It commonly arises in the head and neck region, especially in sun-exposed skin areas or subcutaneous tissue ; however, it can also be found as a metastatic tumor in the lymph nodes. We treated a patient with Merkel cell carcinoma of a lymph node in the parotid gland, who did not exhibit any skin lesions.
Case : A 70-year-old woman presented to us with a history of noticing a swelling in her right neck 15 months earlier. Fine-needle aspiration cytology revealed scattered small atypical cells, in addition to cell clusters exhibiting epithelial adhesion. The atypical cells had fine granular to smudgy chromatin and inconspicuous cytoplasm, similar to the features of a malignant lymphoma. The tumor was finally diagnosed as a Merkel cell carcinoma on the basis of the histological and immunohistochemical findings. No skin lesions were apparent yet.
Conclusion : The characteristic features of MCC, such as the structural pattern of the single cells or cell clusters and the fine granular to smudgy chromatin, are very important cytological features for the diagnosis of MCC in cases where no skin lesions are evident.
