title: Metastatic Merkel cell carcinoma with an unknown primary tumour presenting as lichenoid dermatitis.
abstract: Metastatic Merkel cell carcinoma uncommonly presents with an unidentified primary tumour. We report a patient who first presented with lichenoid dermatitis and was found to have Merkel cell carcinoma involving lymph nodes with an unknown primary site. With the rising incidence of Merkel cell carcinoma, it is important to recognize unusual manifestations of this disease as they may become more common in the future.
authors.affiliation: Department of Dermatology, Greenlane Clinical Centre, Auckland, New Zealand. kwon079@gmail.com
authors.forename: Kenneth Kien Siang
authors.initials: KK
authors.lastname: Wong
authors.forename: Guy Fergus
authors.initials: GF
authors.lastname: Oliver
mesh_terms: D000369:Aged, 80 and over; D019002:CD56 Antigen / Q000032:analysis; D015266:Carcinoma, Merkel Cell / Q000175:diagnosis* / Q000532:radiotherapy / Q000556:secondary*; D018278:Carcinoma, Neuroendocrine / Q000175:diagnosis* / Q000473:pathology / Q000532:radiotherapy; D002294:Carcinoma, Squamous Cell / Q000601:surgery; D015897:Comorbidity; D003872:Dermatitis / Q000175:diagnosis / Q000473:pathology; D017809:Fatal Outcome; D006801:Humans; D007633:Keratins / Q000032:analysis; D017512:Lichenoid Eruptions / Q000175:diagnosis* / Q000473:pathology; D008207:Lymphatic Metastasis; D008297:Male; D009382:Neoplasms, Unknown Primary / Q000473:pathology*; D010751:Phosphopyruvate Hydratase / Q000032:analysis; D012878:Skin Neoplasms / Q000175:diagnosis* / Q000532:radiotherapy / Q000556:secondary*; D016708:Synaptophysin / Q000032:analysis
chemical_list: D019002:CD56 Antigen; D016708:Synaptophysin; D007633:Keratins; D010751:Phosphopyruvate Hydratase