Immunohistochemistry of medullary thyroid carcinoma and C-cell hyperplasia by an affinity-purified anti-human calcitonin antiserum.
BACKGROUND
The diagnosis of medullary thyroid carcinoma (MTC) depends on the calcitonin immunohistochemistry. Familial MTC is associated with C-cell hyperplasia (CCH), whereas sporadic MTC is not. A specific and sensitive calcitonin immunohistochemistry is necessary for the diagnosis of MTC and CCH.


METHODS
An affinity-purified anti-calcitonin antiserum (APxCT) was used for immunohistochemistry of the thyroids of 15 patients with MTC. The thyroids of five patients with familial MTC were studied in detail, with each gland sectioned in 48 areas.


RESULTS
Between three and ten independent MTC were found in each thyroid, and CCH was found in all five patients (24.2%, varying from 8.4-56.3% of the 48 areas from each thyroid). MTC and CCH were localized mainly in the middle third and in the central axis of the thyroid lobes. They often were found together in the same area (in a total of 21 areas for the five thyroids sectioned in 48 areas) but ten areas with MTC did not have CCH, and 37 areas with CCH did not have MTC. In ten thyroids partially studied, CCH was indicated in three patients thought to have sporadic MTC. In two thyroids, with follicular and papillary carcinoma, a higher density of C-cells was found around the tumors, but disease was not characterized as CCH.


CONCLUSIONS
APxCT antiserum increased the immunohistochemical specificity and sensitivity. The distinction of the familial from the sporadic MTC requires a careful and extensive search of CCH. C-cells in high density may be found around follicular cell carcinomas, being a potential source of diagnostic error.
Hayashida
C Y
CY
Department of Medicine, São Paulo University School of Medicine, Brazil.
Alves
V A
VA
Kanamura
C T
CT
Ezabella
M C
MC
Abelin
N M
NM
Nicolau
W
W
Bisi
H
H
Toledo
S P
SP
D000293:Adolescent; D000328:Adult; D002116:Calcitonin / Q000032:analysis* / Q000276:immunology; D002277:Carcinoma / Q000737:chemistry / Q000473:pathology*; D002648:Child; D002846:Chromatography, Affinity; D005190:Family; D005260:Female; D006801:Humans; D006965:Hyperplasia / Q000473:pathology; D007106:Immune Sera; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D013961:Thyroid Gland / Q000737:chemistry / Q000473:pathology*; D013964:Thyroid Neoplasms / Q000737:chemistry / Q000473:pathology*
D007106:Immune Sera; D002116:Calcitonin