Korean J Dermatol.  2008 Mar;46(3):424-426.

A Case of Merkel Cell Carcinoma Differentially Diagnosed by Thyroid Transcription Factor-1

• Kim MH
• Kim CW
• Moon SG
• Shin DH
• Choi JS
• Kim KH

Abstract

Merkel cell carcinoma is a rare aggressive primary neuroendocrine skin tumor. It is more prevalent in elderly patients and commonly occurs as a solitary lesion on the head and neck. This case reports an 84-year old female with an asymptomatic 1x1.5 cm sized erythematous nodule on the right side of the nose that had rapidly enlarged over a one-month period. Histopathologically, it is difficult to differentiate Merkel cell carcinoma from metastatic small cell lung cancer. Thyroid transcription factor-1 (TTF-1) staining was very useful to differentiate Merkel cell carcinoma from metastatic small cell lung cancer. This case was positive for cytokeratin 20, but negative for TTF-1. We report a case that was diagnosed as Merkel cell carcinoma by TTF-1 staining.

Keyword

Merkel cell carcinoma; Thyroid transcription factor-1

MeSH Terms

Aged
Carcinoma, Merkel Cell
Female
Head
Humans
Keratin-20
Neck
Nose
Skin
Small Cell Lung Carcinoma
Thyroid Gland
Keratin-20