Follicle structure-dependency of thyroglobulin and thyroxin staining in the thyroid glands of Graves' disease

H.E. morphology of the thyroid glands from 170 patients with Graves' disease was studied, and the thyroid follicles were classified into two main groups: (1) F pattern, in which the follicles show circle/ellipse on cut sections; (2) P pattern, in which the follicular epithelium protrudes into the lumen or a follicle, is accompanied by proliferation of tubular or microfollicular structures. Studies on three serial sections of 88 thyroid glands stained with hematoxylin and eosin, thyroglobulin (TG), and thyroxin (T4), respectively, revealed the followings: (i) TG/T4 staining is dependent on the follicle structure (i.e., F or P); while the epithelium and colloid including scalloped vesicles in F follicles generally exhibited a direct relationship between TG and T4 staining, those in P follicles often showed an intense TG, but negative T4 staining. (ii) The results of morphological and immunohistochemical studies of P follicles among the cases are consistent with the view that P follicles are in the process of proliferation of immature daughter follicles from a main follicle and of their maturation. (iii) P follicles of Graves' thyroid glands were evaluated as possible non-neoplastic counterparts of well-differentiated follicular and papillary tumors.

Direct evidence for a primary immune response of murine B-lymphocytes after in vitro immunization of dissociated splenocytes

Monoclonal antibodies against human thyroglobulin were generated using splenocytes cultured in vitro with the antigen. When splenocytes from non-immunized mice were used, about 90% of the hybridomas obtained produced immunoglobulins of the IgM class. In contrast, when splenocytes from mice previously immunized in vivo with human thyroglobulin were cultured in vitro with the antigen about 85% of the hybridomas obtained produced immunoglobulins of the IgG class. The properties of the monoclonal antibody produced by hybridoma 3D12, obtained after culturing splenocytes from non-immunized mice with human thyroglobulin, were examined in detail. Monoclonal antibody 3D12 reacted only with human thyroglobulin and not with the murine homologue in an enzyme-linked immunosorbent assay, in immunoblotting experiments and in an immunohistochemical test. These results provide direct evidence that a primary response to an antigen can be elicited by adding the antigen to cultures of splenocytes from non-immunized mice.

Follicular tumor in the sellar region without primary cancer of the thyroid. Heterotopic carcinoma?

A case of a follicular tumor in the sellar region is described without evidence of a primary tumor within the thyroid gland or at a site known to harbor ectopic thyroid tissue. Large amounts of thyroglobulin were readily demonstrated mainly within the colloid of the follicles. The possible development from heterotopic thyroid tissue at this unusual site is discussed.

Immunohistology of anaplastic thyroid carcinoma. A study of 43 cases

Forty-three cases of large cell anaplastic thyroid carcinoma were examined with various antisera. Four histological patterns were identified: spindle cell, giant cell, trabecular and squamous. In 38 cases the epithelial origin was demonstrated with various epithelial markers: 11 cases stained positively for thyroglobulin, 19 for T3 and/or T4, 35 for fat globule membrane antigens, 28 for keratin, 29 for lactoferrin, and one for calcitonin. Five cases were negative for all epithelial markers but could not be characterized further since, except for vimentin, they did not have mesenchymal markers. The immunohistochemical proof of the epithelial nature of anaplastic thyroid tumours is given by staining with anti-keratin and anti-fat globule membrane antigen. In addition the detection of lactoferrin seems useful, but not that of thyroglobulin which was present in only 4% of the spindle cell tumours and in 32-56% of the other histological types. Thirty carcinomas were positive for vimentin; the co-expression of vimentin and epithelial markers seems frequent in thyroid anaplastic carcinomas.

Purification of human thyroid peroxidase using ion exchange liquid chromatography

We have utilized a one step ion-exchange (FPLC Mono Q) purification procedure for the isolation of human thyroid peroxidase (TPO). The purified TPO had the properties of a major microsomal antigen and inhibited the binding of human microsomal autoantibodies to thyroid microsomal membranes. The isolated TPO was free from thyroglobulin and showed, compared with crude microsomal proteins, a reduced background binding with control sera in enzyme-linked immunoassay (ELISA). SDS-gel electrophoresis of the isolated TPO detected one major band with an apparent molecular weight of 105 kD. The antigenicity of the protein was demonstrated by immunoblotting using sera from patients with autoimmune thyroiditis. These results demonstrate that FPLC Mono Q chromatography offers a rapid, quantitative and precise method for large scale purification of TPO with retained enzymatic and antigenic activity for use in ELISA and for further studies on the structure and function of this protein.

Strumal carcinoids of the ovary. An immunohistologic and ultrastructural study

A series of six ovarian strumal carcinoids was examined. The presence of thyroid follicular epithelium was conclusively proved by the presence of follicular cells immunohistochemically positive for thyroglobulin, and by the ultrastructural identification of non-neuroendocrine cells with features of thyroid epithelium lining the follicles. Progressive replacement of thyroid epithelial cells by carcinoid cells accounts for the predominance of neuroendocrine granule-containing cells and the scarcity of thyroid epithelial cells lining many of the follicles. A variety of neuroendocrine hormones and other immunoreactive substances was demonstrated within carcinoid cells, including somatostatin (five cases), chromogranin (five cases), serotonin (five cases), glucagon (four cases), insulin (two cases), and gastrin (one case). Only one case contained calcitonin-positive cells. None were carcinoembryonic antigen-positive or had amyloid deposits. The carcinoid element in five cases stained positively for prostatic acid phosphatase. While strumal carcinoid shares some features with medullary carcinoma of the thyroid gland, it has sufficient differences to warrant a separate designation.

Anaplastic thyroid tumors. Immunohistology

Using an avidin-biotin immunoperoxidase technic, the authors studied 29 anaplastic thyroid tumors (ATTs) to determine the frequency of hormonal (thyroglobulin--TG; calcitonin--CT), epithelial (epithelial membrane antigen, monoclonal keratin), or sarcoma (desmin; alpha-1-antichymotrypsin--ACT; vimentin) markers. Their results indicate that 27% of ATTs stain for TG and none for CT. Fifty-five percent showed epithelial markers, 48% marked for ACT, and 47% for vimentin. Coexpression of keratin and vimentin was found in 39% of cases tested. The expression of the tested antigens did not correlate significantly with histologic pattern (epithelial vs. "sarcomatous"). Of note is the fact that 30% of the ATTs the authors tested expressed none of the markers they examined, indicating total lack of differentiation.

Monoclonal antibodies to human thyroglobulin as probes for thyroglobulin structure

A panel of monoclonal antibodies (mAbs) against human thyroglobulin (hTg) was obtained by somatic fusion of the nonsecreting myeloma cell line P3X66 Ag8/0 and spleen cells of Balb/c mice immunized with purified hTg. Antibody secreting clones were selected by solid phase enzyme immunoassay and analyzed for cross-reaction with Tg from several animal species. Twelve out of 15 mAbs cross-reacted with both rat and mouse Tg and 11 Mabs cross-reacted with bovine Tg. The cross-reaction with mouse Tg paralleled that of rat Tg, whereas discrete differences between the cross-reactivity patterns with bovine Tg were observed. Two clones secreted mAbs specific for hTg. We further characterized the mAbs and found that three mAbs recognized T4-containing determinants and one mAb reacted with both T4 and T3-containing determinants on the Tg molecule. The binding of the mAbs to hormonogenic determinants depended upon the thyroid hormone content of the molecule and the integrity of the three dimensional structure of Tg. One other mAb reacted with four peptides of CNBr-cleaved hTg, indicating the recognition of a repetitive determinant in the hTg molecule distinct from the hormonogenic regions.

Clear cell follicular adenoma of the thyroid

A rare case of follicular adenoma of the thyroid gland composed exclusively of clear cells is described. This case differs from most of the previously reported cases of clear cell thyroid neoplasm in that it was clinically and histologically benign.

Immunohistochemical study of thyroglobulin in thyroid carcinomas with monoclonal antibodies

The effectiveness of an immunoperoxidase technique using four monoclonal antibodies (mAb) is compared to a technique using one polyclonal antibody (pAb) to detect human thyroglobulin (Tg) in paraffin sections of 55 thyroid carcinomas. With the pAb, a positive reaction was found in 82% of the cases. With the four mAb, the presence of Tg was demonstrated in 96.5% of the cases. The mAb gave better results than the pAb on poorly differentiated and anaplastic thyroid carcinomas. Many of the thyroid carcinomas in this study, especially the poorly differentiated and anaplastic type, failed to react with all four mAb to Tg. These results confirm the notion of the heterogeneity of Tg in thyroid carcinomas and indicate that a battery of carefully selected mAb can be successfully used for routine histopathologic detection of Tg in these tumors.

Immunohistochemical study of solid cell nests of the thyroid gland found from an autopsy study

An immunohistochemical study was performed to identify the histogenesis of solid cell nests (SCN) found in 30 of 202 thyroids obtained at autopsy. Immunoperoxidase staining was used to detect the presence of calcitonin, thyroglobulin, thyroxin, low and high molecular weight keratins, and carcinoembryonic antigen (CEA). Results showed that cells forming solid nests had immunoreactivity for calcitonin, low molecular weight keratin, and CEA, but not for thyroglobulin, thyroxin and high molecular weight keratin. Thus, SCN do not result from tangentially cut thyroid follicles (absence of staining for thyroglobulin and thyroxin), nor from a squamous metaplastic process (absence of staining for high molecular weight keratin), but instead they are formed by C-cells because they showed calcitonin immunoreactivity, and neurosecretory granules.

Diffuse sclerosing variant of papillary carcinoma of the thyroid: a histological and immunohistochemical study of three cases

Three cases of an unusual diffuse sclerosing variant of papillary carcinoma of the thyroid occurring in young adults are reported. The tumour is characterized by diffuse involvement of one or both lobes of the thyroid, marked squamous metaplasia, numerous psammoma bodies, extensive interstitial fibrosis and heavy lymphocytic infiltration with formation of germinal centres. Lymphatic and vascular permeation was found in all three cases. An interesting finding was the presence of irregularly disposed thin bundles of smooth muscle within the fibrous stroma, presumably a result of splaying of the smooth muscle of vessel walls by the sclerotic process. The papillary areas of the tumour stained for thyroglobulin and cytokeratin, while the squamous areas stained strongly for cytokeratin but not for thyroglobulin. The tumours were negative for calcitonin and carcinoembryonic antigen, but showed weak staining for S-100 protein. Numerous S-100 positive Langerhans/interdigitating reticulum cells were scattered within the tumour islands and the lymphoid infiltrate, suggesting an immunological reaction mediated by these antigen-presenting cells.

Normal and defective expression of the thyroglobulin gene

Molecular studies of the thyroglobulin (Tg) gene have progressed significantly in recent years. Cloning and sequencing the complete bovine Tg cDNA led to the knowledge of the primary structure of the Tg subunit. This large polypeptidic chain displays a repetitive structure, especially in its amino-terminal half, and bears a striking homology with the acetylcholinesterase molecule of Torpedo californica in its carboxy-terminal portion. The four specific domains known to be involved in the formation of the thyroid hormones have been assigned to both terminal parts of the polypeptide, a location which could play a role in the process leading to hormone release. The very large (greater than 250 kb) Tg gene has been localized on the long arm of chromosome 8 in man, in close linkage with the c-myc oncogene. The study of its structure allowed the characterization of the molecular defect responsible for a congenital flaw in Tg gene expression in a herd of South-African cattle. This work led to the unexpected finding that the Tg pre-mRNA undergoes alternative splicing in normal animals, too. A DNA segment involved in the transcriptional control of Tg gene expression by cAMP has been identified by transfecting primary cultured thyrocytes with recombinant genes.

Hurthle cell thyroid tumors. An immunohistochemical study

Twenty-three Hurthle cell neoplasms of the thyroid were analyzed immunohistochemically for thyroglobulin, carcinoembryonic antigen (CEA), and for immunoreactivity with a monoclonal antibody to p21 ras oncogene product. Both benign and malignant tumors defined by the presence or absence of invasion and metastasis stained positively for thyroglobulin. Most tumors expressed both CEA and p21 ras oncogene product. Clinicopathologic analysis showed that malignant tumors were larger, occurred in slightly older patients (mean age, 52.8 years), and had an almost equal sex distribution, whereas benign tumors were more common in women and occurred in younger patients (mean age, 44.7 years). These results indicate that both benign and malignant Hurthle cell thyroid tumors produce thyroglobulin and express both CEA and p21 ras oncogene product, whereas adjacent normal thyroid tissues showed weak to absent immunoreactivity for p21 ras oncogene product. Because there are no specific immunohistochemical markers to distinguish between benign and malignant Hurthle cell tumors, one needs to rely on traditional histologic features such as invasion and metastasis to distinguish between benign and malignant Hurthle cell neoplasms.

The immunohistochemical demonstration of thyroglobulin in human thyroid tumour xenografts using a monoclonal antibody

A monoclonal antibody (RBU/01) was raised against human thyroglobulin and its suitability for the immunohistochemical staining of thyroglobulin was determined on fixed, wax-embedded tissue, using the peroxidase anti-peroxidase (PAP) method. The antibody was then used to demonstrate the expression of human thyroglobulin in sections of a human follicular carcinoma of the thyroid which had been grown in immunodeficient mice. It is concluded that the immunohistochemical evaluation of the xenografts with the antibody provides useful information on this xenograft system as a potential model for thyroid carcinoma.

Congenital goiter sustaining normal level of serum triiodothyronine

We attempted to elucidate the deficient site of thyroid hormone biosynthesis in the thyroid gland and the mechanism of sustaining normal T3 level in sera of a patient with congenital goiter. TY, a 8-yr-old boy, first noted the onset of a diffuse goiter at the age of 2. There was no clinical evidence of hypothyroidism except for the slight impairment of intellectual development and the awkward physical activity. BMR, T3-RSU and T4 showed low values (-13%, 20.8% and 2.2 micrograms/dl), but serum T3 was normal (180 ng/dl). Serum TSH was 18 microU/ml. The intrathyroidal T3 and T4 were slightly low. Thyroidal 131I uptake was high, but KSCN discharge test was negative. Percent distribution of 131I labelled amino acids in the pancreatin digested thyroid homogenate was 17.4% in MIT, 33.4% in DIT and 11.3% in T3 and T4. Thyroid iodide peroxidase activities in mitochondrial and microsomal fractions were slightly low (19.6 and 26.8 (normal: 32 +/- 3.0 and 37.4 +/- 9.5) mumoles/mg protein). The activity was not increased by the addition of hematin. Thyroglobulin was found to be normal. A biological half life of 131I labelled T4 was shorter (3.5 days) than that of the normal. Electron microscopic examination exhibited the increment and expansion of endoplasmic reticulum in the follicular cell. Low iodide peroxidase activity of this patient may correlate to low T3 and T4 level in the thyroid cell. Moreover, shortened biological half life of T4 implies that normal T3 level in serum is sustained by the accelerated conversion of T4 to T3 in peripheral tissues.(ABSTRACT TRUNCATED AT 250 WORDS)

Some characteristics of soluble thyroid proteins in human fetus during morphogenesis of follicular structure

Soluble thyroid proteins of the human fetus were studied in parallel with the formation of the follicular structure of the gland using polyacrylamide disc electrophoresis and a radioimmunological method for measuring thyroglobulin (Tg). The study covered 24 fetuses obtained after sectio parvae performed at 12-28 weeks of gestation for socio-medical reasons. Before the first trimester of gestation the human fetal thyroid, which did not have an organized follicular structure contained a significant amount of the 12S protein fraction, but only trace amounts of Tg. In the cells of a gland of afollicular structure immunofluorescent material was confirmed by reaction with anti-Tg antibodies. Later, with the formation of follicles and the appearance of follicular colloid, the absolute and relative amounts of Tg in the fetal gland increased, while the 12S subunit decreased. The Tg content in the fetal thyroid was positively correlated with the total weight of the gland, i.e. gestational age. The T4 and T3 contents in Tg of human fetal thyroids (20-24 weeks) amounted to 0.54 +/- 0.39 and 0.12 +/- 0.09 mole/Tg mole, respectively. The 27 S iodoprotein was not found in any of the extracts of fetal thyroids with formed follicles and considerable amounts of follicular colloid. The finding of the 12 S protein in the human thyroid during early fetal life, i.e. in the prefollicular phase, implies a low rate of aggregation of Tg subunits (12 S). The absence of the 27 S iodoprotein from the fetal thyroid with organized follicular structure suggests the yet incomplete morphological and biochemical maturation of the fetal gland.

Characterization of a hormonogenic domain from human thyroglobulin

A polypeptide domain of molecular mass near 22 kDa was purified from CNBr-digest of iodine poor human thyroglobulin (hTgb). This fragment represents the N-terminal part of the hTgb molecule and consequently contains the preferential hormonogenic tyrosine 'acceptor' of the protein. This fragment could correspond to the non-iodinated and unreduced form of the thyroxinyl-containing 26 kDa peptide previously purified from reduced and iodinated hTgb. This 22 kDa fragment is capable by itself, i.e. independently of the remaining hTgb molecule, of synthesizing thyroxine with a high efficiency after in vitro iodination. Its study should constitute a valuable way to identify at least one of the hormonogenic tyrosine 'donor' residues of hTgb.

Small cell carcinoma of the thyroid. A reclassification of cases originally diagnosed as small cell carcinomas of the thyroid

99 cases of undifferentiated carcinomas of the thyroid and nine cases of primary malignant Non-Hodgkin lymphomas of the thyroid were examined from 1967 to 1983 in our institute. Among the undifferentiated carcinomas nine cases were classified as small cell subtype. Over the years, the histopathological handling in regard to small cell subtype of undifferentiated carcinoma and primary malignant Non-Hodgkin lymphoma has changed. The frequency of primary malignant Non-Hodgkin lymphoma has increased conspicuously in the last few years, whereas the number of small cell carcinomas decreased. A reclassification, based on immunohistochemical investigation for tumor markers of the nine cases originally diagnosed as small cell carcinomas from 1967 to 1983 revealed that five cases were poorly differentiated carcinomas or undifferentiated carcinomas of the spindle cell type. In three cases the primary diagnosis had to be revised into malignant Non-Hodgkin lymphoma of the diffuse "histiocytic" type. The postmortem examination of the patient with the remaining small cell carcinoma "of the thyroid" revealed a clinically undetected small cell carcinoma of the lung with metastases to the cervical lymph nodes and the thyroid gland. These findings are in agreement with the results of several recently published papers indicating that true small cell carcinoma of the thyroid must be a very rare tumor.

Goiter size and thyroid function in an endemic goiter area in northern Italy

Thyroid function was studied in a large number of subjects residing in Varsi, a town in the province of Parma, Italy. In this area, endemic goiter associated with moderate iodine deficiency [59 +/- 3 (+/- SE) microgram iodine/g creatinine], as defined by WHO criteria, affects 65% of the population. Serum T4, T3, thyroglobulin (Tg), and TSH concentrations were measured by RIA in 1218 subjects. The TSH response to TRH was determined in 108 subjects selected randomly from the groups with different grades of goiter. No significant change in serum T4 concentrations was found in subjects with different grades of goiter. Serum T3 concentrations were higher in subjects with the larger goiters. Serum Tg concentration progressively increased, and serum TSH progressively decreased with increasing goiter size. The TSH response to TRH was diminished in subjects with larger goiters. The findings of decreasing serum TSH concentrations and blunted TSH responses to TRH as goiter size increased suggest the possibility of autonomous thyroid function in the larger goiters in subjects residing in this area of moderate iodine deficiency.

Epithelial markers in thyroid carcinoma: an immunoperoxidase study

Ten cases each of papillary, follicular, anaplastic and medullary carcinoma of the thyroid were stained for thyroglobulin, calcitonin, epithelial membrane antigen (EMA), carcinoembryonic antigen (CEA) and cytokeratin (CAM 5.2). Monoclonal or affinity purified polyclonal antibodies, and an indirect immunoperoxidase technique were used. All the papillary and follicular tumours, 5/10 anaplastic and 3/10 medullary carcinomas contained thyroglobulin. Only the 10 medullary carcinomas stained positively for calcitonin. Three out of 10 papillary, 1/10 follicular, 0/10 anaplastic and 10/10 medullary carcinomas were positive for CEA. Nine out of ten papillary, 7/10 follicular, 2/10 anaplastic and 3/10 medullary carcinomas were positive for EMA. Ten out of 10 papillary, 10/10 follicular, 5/10 anaplastic and 10/10 medullary carcinomas were positive for cytokeratin. The presence of calcitonin and CEA is of value in the diagnosis of medullary carcinoma, and enable its distinction from anaplastic thyroid carcinoma. Thyroglobulin is a useful marker in thyroid carcinomas.

Identification of unsuspected thyroid carcinoma using immunoperoxidase for thyroglobulin

Two patients with poorly differentiated metastatic cancer were shown to have metastatic thyroid carcinoma. Each patient had poorly differentiated cancer and remaining thyroid tissue in the neck. The diagnosis was secured using the immunoperoxidase technique with an antibody against thyroglobulin. The proper evaluation of patients with carcinoma of unknown primary involves specific tissue identification using special techniques in pathology.

Fine needle aspiration in studies of thyroglobulin (Tg). Iodothyronine and iodine contents of Tg from patients with multinodular euthyroid goitre

Fine needle aspiration from the thyroid gland was performed in 10 patients with multinodular euthyroid goitre. This was done to evaluate the possibility of obtaining sufficient quantities of thyroglobulin by this procedure to allow biochemical characterization. For comparison aspiration from normal thyroid tissue was performed in seven subjects during operation for solitary thyroid lesions (cancer or cysts). The total amount of Tg in aspirate was, goitre 666 +/- 171 micrograms (mean +/- SE), normal 177 +/- 52 micrograms; purified Tg contained, goitre vs. normal: iodine 9.1 +/- 2.2 vs. 26 +/- 3.9; T4 0.86 +/- 0.39 vs. 4.0 +/- 0.7; T3 0.080 +/- 0.024 vs. 0.28 +/- 0.06 mol/mol Tg (all significantly different), compatible with iodine deficiency pattern in Tg from the patients with goitre. Similar values were obtained if iodine and iodothyronines were measured in crude aspirate (after alkaline ashing and pronase hydrolysis, respectively) and related to the amount of Tg in aspirate measured by radioimmunoassay; thus avoiding the cumbersome purification of Tg. Hence fine needle aspiration of the thyroid can be used to obtain Tg for biochemical analyses. This considerably facilitates Tg studies in humans for clinical or investigative purposes.

Phosphorylation of the oligosaccharide of uteroferrin by UDP-GlcNAc:glycoprotein N-acetylglucosamine-1-phosphotransferases from rat liver, Acanthamoeba castellani, and Dictyostelium discoideum requires alpha 1,2-linked mannose residues

We have investigated the oligosaccharide requirements of the UDP-GlcNAc:glycoprotein N-acetylglucosamine-1-phosphotransferases from rat liver, Acanthamoeba castellani, and Dictyostelium discoideum. Uteroferrin, an acid hydrolase, was phosphorylated by the three N-acetylglucosaminylphosphotransferases, and the phosphorylated oligosaccharides were isolated and analyzed by ion suppression high performance liquid chromatography. In all three cases, the phosphorylated species contained 6 or more mannose residues. Phosphorylation of the Man5GlcNAc2 oligosaccharide could not be detected even though this was the major species on the native uteroferrin. The Man5GlcNAc2 oligosaccharides lack alpha 1,2-linked mannose residues, whereas the larger oligosaccharides contain 1 or more mannose residues in this linkage. Treatment of intact uteroferrin with an alpha 1,2-specific mannosidase-generated molecules whose oligosaccharides consisted almost entirely of species with 5 mannose residues. The N-acetylglucosaminylphosphotransferases could no longer phosphorylate such molecules. These data indicate that at least 1 alpha 1,2-linked mannose residue must be present on uteroferrin's oligosaccharide for phosphorylation to occur.