High molecular weight caldesmon positive stromal cells in the capsule of thyroid follicular tumours and tumour-like lesions.
OBJECTIVE
To investigate the smooth muscle nature of the spindle stromal cells in the capsule of thyroid tumours and tumour-like lesions.


METHODS
Immunostaining for high molecular weight caldesmon (HCD), a highly specific marker for smooth muscle differentiation, was performed in 70 primary thyroid tumours and tumour-like lesions (21 hyperplastic nodules, 29 follicular adenomas, five minimally invasive follicular carcinomas, six widely invasive follicular carcinomas, and nine encapsulated papillary carcinomas).


RESULTS
HCD positive stromal cells (HCD+ cells) were detected in the capsule of 20 of the 21 hyperplastic nodules, and all of the 29 follicular adenomas and five minimally invasive follicular carcinomas, whereas HCD+ cells were seen in the capsule of only four of the six widely invasive follicular carcinomas and no HCD+ cells were seen in the capsule of the nine encapsulated papillary carcinomas examined.


CONCLUSIONS
The presence of HCD+ cells in the capsule is characteristic of thyroid follicular tumours and tumour-like lesions. The stromal cells in the capsule of thyroid follicular tumours and tumour-like lesions are different from those of encapsulated papillary carcinoma.
Nakayama
H
H
First Department of Pathology, Kochi Medical School, Nankoku-city, Kochi 783-8505, Japan. nakayamh@hiroshima-u.ac.jp
Enzan
H
H
Miyazaki
E
E
Moriki
T
T
Kiyoku
H
H
Toi
M
M
Kuroda
N
N
Hiroi
M
M
D018263:Adenocarcinoma, Follicular / Q000737:chemistry* / Q000473:pathology; D000236:Adenoma / Q000737:chemistry; D014408:Biomarkers, Tumor / Q000032:analysis*; D002148:Calmodulin-Binding Proteins / Q000032:analysis*; D006801:Humans; D006965:Hyperplasia; D008970:Molecular Weight; D009361:Neoplasm Invasiveness; D009363:Neoplasm Proteins / Q000032:analysis*; D011230:Precancerous Conditions / Q000737:chemistry; D017154:Stromal Cells / Q000737:chemistry; D013961:Thyroid Gland / Q000473:pathology; D013964:Thyroid Neoplasms / Q000737:chemistry* / Q000473:pathology
D014408:Biomarkers, Tumor; D002148:Calmodulin-Binding Proteins; D009363:Neoplasm Proteins