Merkel cell carcinoma of the skin v metastatic small cell carcinoma of the lung

Use TTF-1, CK20 and neurofilament in combination:



Merkel cell carcinoma of skin

Small cell carcinoma of lung

Atypical basal cell carcinoma



 0/212, 0/183 ,0/234 ,0/115, 0/136, 0/2110, 0/2211, 1/3012

35/362, 27/283, 43/524, 10/105, 11/136, 28/3310, 9/911, 43/5912


CK 20

33/341, 16/212, 16/183, 23/234, 10/115, 13/136, 95%10, 19/2211

1/371, 1/362, 1/283, 0/524, 0/105 ,1/136, 33%10, 0/911




12/136, 25/407, 17/258, 9/99

0/136, 0/227, negative7, 0/289








0/3012 49/5912  


1 Chan JKC et al. Cytokeratin 20 immunoreactivity distinguishes Merkel cell (primary cutaneous neuroendocrine) carcinomas and salivary gland small cell carcinomas from small cell carcinomas of various sites. Am J Surg Pathol 1997;21:226-234.

2 Bryd-Gloster A et al. Differential expression of thyroid transcription factor 1 in small cell lung carcinoma and Merkel cell tumor. hum Pathol 2000;31:58-62.

3 Ordonez NG. Value of thyroid transcription factor-1 immunostaining in distinguishing small cell lung carcinomas from other small cell carcinomas. Am J Surg Pathol 2000;24:1217-1223.

4 Cheuk W et al. Immunostaining for thyroid transcription factor-1 and cytokeratin 20 aids in the distinction of small cell carcinoma from Merkel cell carcinoma, but not pulmonary from extrapulmonary small cell carcinoma. Arch Pathol Lab Med 2001;125:228-231.

5 Leech, S. N., Kolar, A. J., Barrett, P. D., Sinclair, S. A., Leonard, N. Merkel cell carcinoma can be distinguished from metastatic small cell carcinoma using antibodies to cytokeratin 20 and thyroid transcription factor 1. J Clin Pathol 2001;54:727-729

6 Bobos M, Hytiroglou P, Kostopoulos I, et al. Immunohistochemical distinction between merkel cell carcinoma and small cell carcinoma of the lung. Am J Dermatopathol 2006; 28:99-104

7 Schmidt U, Muller U, Metz KA, et al. Cytokeratin and neurofilament protein staining in Merkel cell carcinoma of the small cell type and small cell carcinoma of the lung. Am J Dermatopathol 1998; 20:346-51

8 Johansson L, Tennvall J,Akerman M Immunohistochemical examination of 25 cases of Merkel cell carcinoma: a comparison with small cell carcinoma of the lung and oesophagus, and a review of the literature. Apmis 1990; 98:741-52

9 Shah IA, Netto D, Schlageter MO, et al. Neurofilament immunoreactivity in Merkel-cell tumors: a differentiating feature from small-cell carcinoma. Mod Pathol 1993; 6:3-9

10 Hanly AJ, Elgart GW, Jorda M, et al. Analysis of thyroid transcription factor-1 and cytokeratin 20 separates merkel cell carcinoma from small cell carcinoma of lung. J Cutan Pathol 2000; 27:118-20

11 Yang DT, Holden JA,Florell SR. CD117, CK20, TTF-1, and DNA topoisomerase II-alpha antigen expression in small cell tumors. J Cutan Pathol 2004; 31:254-61

12 Ralston J, Chiriboga L, Nonaka D. MASH1: a useful marker in differentiating pulmonary small cell carcinoma from Merkel cell carcinoma. Mod Pathol. 2008 Nov;21(11):1357-62.


This page last revised 22.11.2008.