Faculty Collaboration Database

Immunostaining for thyroid transcription factor 1 and cytokeratin 20 aids the distinction of small cell carcinoma from Merkel cell carcinoma, but not pulmonary from extrapulmonary small cell carcinomas. Arch Pathol Lab Med 2001 Feb;125(2):228-31

Date

02/15/2001

Pubmed ID

11175640

DOI

10.5858/2001-125-0228-IFTTFA

Scopus ID

2-s2.0-0035110093 (requires institutional sign-in at Scopus site)   238 Citations

Abstract

OBJECTIVE: To study the expression of thyroid transcription factor 1 (TTF-1) and cytokeratin 20 (CK20) in pulmonary small cell carcinomas, extrapulmonary small cell carcinomas, and Merkel cell carcinomas, and thereby determine whether these markers are helpful in distinguishing these 3 groups of small cell neuroendocrine carcinomas.

MATERIALS AND METHODS: Immunostaining for TTF-1 and CK20 was performed in 102 cases of small cell carcinoma (pulmonary, 52; extrapulmonary, 50) and 23 cases of Merkel cell carcinoma. The results for the 3 groups were compared.

RESULTS: Thyroid transcription factor 1 was expressed in 82.7% of pulmonary small cell carcinomas, 42.0% of extrapulmonary small cell carcinomas (range, 33.3--53.3% for the various sites), and 0% of Merkel cell carcinomas. Cytokeratin 20 staining was consistently negative in pulmonary small cell carcinomas, and positive in 4.0% of extrapulmonary small cell carcinomas and 100% of Merkel cell carcinomas.

CONCLUSIONS: Immunostaining for TTF-1, especially when combined with immunostaining for CK20, can aid in the distinction between Merkel cell carcinoma and small cell carcinoma (both pulmonary and extrapulmonary). However, in individual cases, these markers cannot be used to distinguish between pulmonary and extrapulmonary small cell carcinomas due to the extensive overlap in immunophenotypes.

Author List

Cheuk W, Kwan MY, Suster S, Chan JK

MESH terms used to index this publication - Major topics in bold

Carcinoma, Merkel Cell
Carcinoma, Small Cell
Diagnosis, Differential
Digestive System Neoplasms
Female
Genital Neoplasms, Female
Humans
Intermediate Filament Proteins
Keratin-20
Lung Neoplasms
Male
Nuclear Proteins
Prostatic Neoplasms
Skin Neoplasms
Thyroid Nuclear Factor 1
Transcription Factors
Urinary Bladder Neoplasms