Expression of stratified epithelial-type cytokeratins in hyalinizing trabecular adenomas supports their relationship with papillary carcinomas of the thyroid.
OBJECTIVE
To evaluate the cytokeratin pattern of expression of hyalinizing trabecular adenomas and to verify whether or not these tumours, that share morphological features with papillary carcinomas, present the stratified epithelial-type cytokeratins commonly found in ordinary papillary carcinomas.


RESULTS
This study consisted of the immunohistochemical detection of simple and stratified epithelial type cytokeratin filaments in a series of six hyalinizing trabecular adenomas, three papillary carcinomas with a trabecular growth pattern and two carcinomas combining hyalinizing trabecular and papillary patterns. Simple epithelial-type cytokeratins 7, 8, 18 and 19 were found in every case. Expression of the stratified epithelial-type cytokeratins 1, 5/6 and/or 13 was detected in four hyalinizing trabecular adenomas.


CONCLUSIONS
Based on this, as well as on the cytological features and on the frequent co-occurrence of hyalinizing trabecular adenoma and papillary carcinoma, we suggest that the former lesion may be considered a peculiar encapsulated variant of papillary carcinoma.
Fonseca
E
E
Department of Pathology, University of Porto (IPATIMUP), Portugal.
Nesland
J M
JM
Sobrinho-Simões
M
M
D000236:Adenoma / Q000378:metabolism*; D000328:Adult; D000368:Aged; D002291:Carcinoma, Papillary / Q000378:metabolism* / Q000473:pathology; D004848:Epithelium / Q000378:metabolism; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007633:Keratins / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D013964:Thyroid Neoplasms / Q000378:metabolism* / Q000473:pathology
D007633:Keratins