Kristine Kucera, PA-C, MPAS, DHS
“Wrinkles only go, where the smiles have been,” is one of my favorite Jimmy Buffett quotes. A few days ago, Jimmy passed away from complications of Merkel Cell Carcinoma, which is a very rare form of skin cancer. In my 28 years of clinical practice, I have seen this type of cancer once, and it was when I was employed at MD Anderson Cancer Center. Let’s take this opportunity to do a quick review of the signs and symptoms of Merkel Cell Carcinoma.
Merkel cells were originally described in the late 1800s by Friedrich Merkel, a German anatomist. These cells are found in the epidermis of human skin and, although their role is not completely understood, they are thought to be a type of neuroendocrine cell exhibiting features of nerve cells and hormone producing cells. They are positioned very close to nerve endings in the skin and serve as touch cells relaying information such as texture and pressure to the brain. They are found mostly on the fingertips, face and lips.
The reported annual incidence of Merkel cell carcinoma (MCC) is 0.2-0.45 cases per 100,000 population. This rare cancer occurs 100 times less frequently than melanoma. More than half occur on the head and neck of elderly people, in areas of actinically damaged skin. Common appearance is an erythematous or violaceous mass that is painless and often gets ignored due to the lack of symptoms. Bleeding and superficial ulceration are late findings suggestive of advanced disease. Regional lymph node metastasis is common, even with tumors smaller than 2 cm.
Guidelines released in 2015 by a collaborative group of multidisciplinary experts from the European Dermatology Forum (EDF), the European Association of Dermato-Oncology (EADO), and the European Organization of Research and Treatment of Cancer (EORTC) included the following regarding the management of Merkel cell carcinoma (MCC):
- The primary tumor should be excised with 1-2 cm margins
- In patients with regional lymph node involvement, radical lymphadenectomy is recommended
- Adjuvant radiation therapy may be considered in patients with multiple affected lymph nodes of extracapsular extension
- In unresectable metastatic Merkel cell carcinoma, chemotherapy achieves high remission rates; however, responses are usually short-lived
- Treatment within clinical trials is regarded as a standard of care in disseminated Merkel cell carcinoma
Merkel cell carcinoma (MCC) is a deadly disease with a poor outlook for survival. Local recurrence occurs in 44% of patients, usually within 5 months after the primary lesion is treated. About 15% of patients have palpable nodes at the time of diagnosis. Lymph node metastases eventually develop in 55% of patients, and distant metastases develop in 34%. Most metastases occur before the eighth month after diagnosis.
You can read more about rare cancers in previous blog posts.
Kristine Kucera, PA-C, MPAS, DHS, is Assistant Clinical Professor, University of Texas Southwestern, Medical Center PA Program, Dallas, TX. She is a member of the DEF Advisory Council.
References:
1. https://emedicine.medscape.com/article/870538-overview
2. https://merkelcell.org/about-mcc/what-is-a-merkel-cell/