Note: last updated before 2017

Merkel cell carcinoma is an aggressive neuroendocrine carcinoma arising in the skin. Approximately 50% of cases occur in the head and neck region - with a male predominance and higher incidence in the elderly. Merkel cell carcinom is associated with sun exposure, immunosuppression and has recently been identified to be associated with a new polyomavirus termed Merkel cell polyomavirus (Houben et al. 2010). Five year survival rates range from 35 to 75% with up to 75% developing a loco-regional recurrence (Balakrishnan et al. 2013).

54 consecutive cases of Merkel cell carcinoma of the head and neck (culled from 116 cases overall during this period) were managed from 1998 to 2009 at the Peter MacCallum cancer in center in Melbourne Australia. Analysis of this group of patients resulted in the suggestion that treatment include excision of the primary to clear margins if possible with adjuvant radiotherapy to the surgical bed and to the regional lymphatics (Balakrishnan et al. 2013). A positive margin identified from the resection was not associated with a worse outcome - leading these investigators to suggest conservative resection when vital structures are encroached upon with the need for postoperative irradiation emphasized. Although these authors recognized reports of benefit from treatment with chemotherapy reported with 60% response rates, they did not find benefit from their instituitions use of carboplatin and etoposide through their retrospective review (class 2C evidence) and therefore did not recommend its use.

A recent case report of treatment of a 92 yo with a large cheek merkel cell carcinoma with imatinib with a complete response (and death due to other causes 6 months later without sign of recurrence) offers support for targetted use of tyrosine kinase inhibitor therapy for selected cases (Dagmara et al. 2013).

References

Dagmara L et al: Clinical remission of Merkel cell carcinoma after treatment with imatinib  Journal of the Ameircan Academy of Dermatology 2013 vol:69 isse:4 p181-3

Balakrishnan V et al: Benefits of combined modality treatment of Merkel cell carcinoma of the head and neck: single institution experience. Journal of laryngology and otology  2013 vol:127 iss:9 p 908-916

Houben R. Shuda M, Weinkam R, Schrama D, Feng H, Chang Y, Moore PS, and Becker JC: Merkel cell polyomavirus-infected Merkell cell caricnoma cells require epxression of viral T antigens. J Virol 2010 Jul;84(14):7064-72