Three-phase bone scintigraphy pattern of loosening in uncemented hip prostheses

The three-phase bone scintigraphy pattern of loosening in uncemented hip prostheses (UHPs) has not previously been elucidated. We evaluated 28 patients with complicated UHPs who had undergone total hip arthroplasty a very long time previously (range 3-20 years, mean 8.4). All the patients were surgically reviewed: 26 UHPs were found to be loosened and two infected. Nine asymptomatic UHPs were taken as controls. The dynamic phase was invariably negative in both loosened and asymptomatic UHPs while markedly positive in the infected ones. The blood pool phase was positive to various degrees in 16 of the 26 loosened UHPs as well as in the infected UHPs, but was invariably negative in painless replacements. In the bone phase, areas of significantly (discrete to marked) increased uptake were observed in all the loosened prostheses as well as in two-thirds of the asymptomatic ones. However, the regions of the lesser trochanter and/or tip and/or shaft were involved exclusively in the case of the loosened UHPs, and diffuse periprosthetic uptake was found only with loosened or infected implants. Areas of slight methylene diphosphonate (MDP) uptake were found at every periprosthetic site and areas of discrete to marked MDP uptake were commonly found in the acetabulum and/or the greater trochanter with both loosened and painless prostheses and are thus considered to be nonspecific findings.

Natural course of subclinical hypothyroidism in Down's syndrome: prospective study results and therapeutic considerations

Pathogenesis, natural course and therapeutic management of subclinical hypothyroidism (SH) in Down's syndrome (DS) remain object of debate in literature. In the present study thyroid function, antithyroid antibody (ATA) prevalence and serum lipid concentrations were investigated in a group of 344 Down patients (DP) and data were compared with those obtained from a control group of 257 age and sex matched healthy subjects. Thyroid function and ATA prevalence were also studied in 120 parents of DP. SH prevalence was clearly higher in DP (32.5% of cases) than in controls (1.1%) and parents (0%). Similarly, ATA prevalence was higher in DP (18% of cases) than in controls (5.8%) and parents (6.6%). In spite of this, no correlation was found in DP between SH and ATA prevalences, since ATA were detected in 18.7% of SH-DP and in 15.8% of euthyroid DP. Thus, circulating ATA were not detected in the majority of SH-DP. No significant differences regarding T4, FT4, T3 and serum lipid levels among SH and euthyroid DP and controls were found. Moreover, TSH levels were only slightly increased, generally less than 10 microU/ml, in most cases of SH-DP. Follow-up was longer than 24 months (range 2-7 years, mean 3.1) in a group of 201 DP: two different patterns of SH course were observed, mainly depending on the presence or the absence of circulating ATA. In particular, 35.7% of ATA-positive SH-DP developed a clinically evident thyroid disease (overt hypothyroidism or hyperthyroidism), while no similar case was recorded among ATA-negative SH-DP.(ABSTRACT TRUNCATED AT 250 WORDS)

Different features of pulmonary metastases in differentiated thyroid cancer: natural history and multivariate statistical analysis of prognostic variables

We studied 134 patients with differentiated thyroid cancer and pulmonary metastases. All were treated with total or near total thyroidectomy, radioiodine and L-thyroxine. The prognostic value of the following variables in three groups of patients were evaluated by univariate and multivariate analysis: age at diagnosis, sex, histologic type, tumor extension, cervical lymph node metastases, mediastinic metastases, presence of metastases in distant sites other than lungs (multiple distant metastases) and morphological (chest x-rays) and functional (131I uptake) features of lung metastases. Univariate analysis identified patient age (p < 0.0001), morphological and functional features of lung metastases (p < 0.0001), presence of multiple distant metastases (p < 0.0001) and histologic type (p = 0.04) as significant prognostic factors. Multivariate analysis showed only morphological (p = 0.0014) and functional (p < 0.0001) features of lung metastases and the presence of multiple distant metastases (p = 0.01) as significant and independent variables. The data show that early (pre-radiological) scintigraphic diagnosis and 131I therapy of lung metastases appear to be the most important elements in obtaining both a significant improvement in survival rate and a prolonged disease-free time interval in these patients.

TSH-receptor antibody (TSH-R Ab) variations in patients undergoing subtotal thyroidectomy for Graves' disease: a prospective study

Variations in circulating TSH-R Ab were correlated to the thyroid function outcome in a group of 43 patients who received subtotal thyroidectomy for Graves' disease. There were 36 females and 7 males, ranging in age from 18 to 63 years (mean +/- SD = 41.3 +/- 9.5 years). All patients were operated on by the same surgeon, with the same surgical technique, leaving a remnant of 4-5 grams of thyroid. When a condition of subclinical hypothyroidism was found after surgery, thyroid function was tested again within 2-3 months. Thus, in cases with persisting elevated TSH levels, L-thyroxine was administered. During follow-up a progressive decrease in the prevalence of euthyroid patients was documented (51.2% at 3 months, 30.2% at 2 years, 28% at 4 years), with a parallel increase in cases of subclinical and overt hypothyroidism. Two patients with persisting detectable TSH-R Abs showed recurrent disease within 2 years after surgery. No case of relapse was observed among patients who became TSH-R Ab negative. TSH-R Abs remained detectable in 68% of euthyroid and in 63.6% of subclinical hypothyroid patients before L-thyroxine administration, whereas TSH-R Abs remained positive in only 30% of patients with overt hypothyroidism, and became undetectable in most patients with subclinical hypothyroidism after L-thyroxine was begun. The persistence of TSH-R Abs in patients who have undergone surgery for Graves' disease should be considered a risk condition for relapse. These patients must be carefully followed-up.(ABSTRACT TRUNCATED AT 250 WORDS)

Pregnancy after high therapeutic doses of iodine-131 in differentiated thyroid cancer: potential risks and recommendations

Seventy female patients who had been treated with high doses of iodine-131 for differentiated thyroid cancer (DTC) and who had a subsequent pregnancy were evaluated. The total 131I dose ranged from 1.85 to 16.55 GBq (mean +/- SD = 4.39 +/- 25.20 GBq). Age at first therapy ranged from 15 to 36 years (mean +/- SD = 24.3 +/- 5.0 years) and the interval from 131I therapy to pregnancy varied from 2 to 10 years (mean +/- SD = 5.3 +/- 2.8 years). The estimated radiation dose to the gonads ranged from 10 to 63 cGy (mean +/- SD = 24.0 +/- 13.5 cGy). All patients were treated with L-thyroxine at doses capable of suppressing thyroid-stimulating hormone. Seventy-three children were followed-up and seven pregnancies are still in progress. One child was affected by Fallot's trilogy and three had a low birth weight through with subsequent normal growth; the others were healthy with subsequent normal growth. No newborn with clinical or biochemical thyroid dysfunctions was found. Two spontaneous abortions during the second month of pregnancy were recorded. One of two patients in question subsequently had two healthy children. On the basis of these data, previous administration of high 131I doses does not appear to be a valid reason for dissuading young female DTC patients from considering pregnancy. However, patients should be advised to avoid pregnancy after 131I administration for a period sufficient to ensure complete elimination of the radionuclide and to permit confirmation of complete disease remission, i.e. at least 1 year in our opinion.

Metastatic thyroid carcinoma of the adrenal gland

Follicular thyroid carcinoma may spread distant metastases in sites such as bone, lung and brain. In our series of 448 patients with follicular thyroid carcinoma, distant metastases were present in 25% of cases. We report here a case of follicular thyroid carcinoma with a single metastasis at the right adrenal gland, that was found 12 years after total thyroidectomy and radioiodine therapy. Chest X ray, neck and liver echography and total body scan (TBS), performed after radioiodine therapy, were negative. During hormone therapy, serum thyroglobulin (Tg) levels were less than 1 ng/ml until 1990, and then Tg progressively increased in eighteen months up to 149 ng/ml. A new TBS was negative. At computer tomography a node at the right adrenal gland was found. The patient underwent adrenalectomy and histology showed a metastatic follicular thyroid cancer with Hurthle cells. After 1 and 5 months from surgery Tg serum levels were 0.9 ng/ml. This case shows once again the importance of Tg serum levels during follow-up of differentiated thyroid cancer.

Differentiated thyroid carcinoma in the elderly

Prognostic factors and therapeutic results in a group of 268 patients with differentiated thyroid cancer (DTC) aged over 60 years are reported. These cases were selected from a total of 1457 DTC-patients seen at our Center from 1967 to 1987. All elderly patients underwent total thyroidectomy, and were treated with 131I therapy and suppressive hormonal therapy. Moreover, external radiotherapy was performed in 20% and chemotherapy in 3.8% of all cases. Follow-up included periodical clinical examination, serum Thyroglobulin (Tg) determination, 131I total body scan (TBS), and echographic and radiologic survey. Several unfavorable prognostic factors were identified in elderly patients with DTC. In comparison with data obtained in a group of patients under 60 years of age, 1) the follicular histologic type was increased, papillary/follicular ratio was 1.1 vs 2.6; 2) the F/M ratio was decreased, 1.5 vs 2.8 for papillary tumors, and 1.7 vs 3.6 for follicular tumors; 3) the rate of cases with local extrathyroid tumor growth and distant metastases was higher, and 4) rates of metastases to bone and metastases with low 131I uptake were increased. Moreover, the 10-year survival rate in elderly patients with lymph node and distant metastases was significantly reduced compared to younger patients, both for papillary and follicular cancer. The finding of detectable serum Tg levels was well correlated with the presence of metastatic disease. Moreover, Tg sensitivity was higher than TBS in showing the presence of metastatic foci. DTC in elderly people must be considered an aggressive tumor both for follicular and papillary histologic types. A radical approach is recommended: total thyroidectomy, 131I administration, and suppressive hormonal therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical meaning of circulating antithyroglobulin antibodies in differentiated thyroid cancer: a prospective study

In recent studies of patients with differentiated thyroid cancer (DTC), an association between the persistence of tumor and the presence of circulating anti-thyroglobulin antibodies (TgAbs) have been described. The aim of the present study was to evaluate TgAb variations before and after total thyroid ablation and to correlate TgAb levels to the outcome of disease. Forty-three patients with DTC were studied (35 female, 8 male; 33 patients had papillary cancer and 10 follicular cancer). Tumor was intrathyroid in 20 cases, had spread to the lymph nodes in 19 and to the lungs in 4. All patients underwent total thyroidectomy and 131I therapy, and were then treated by suppressive doses of L-thyroxine. After a mean follow-up of 3.55 yr, TgAbs became undetectable in 24 patients (all were considered tumor-free), whereas TgAbs remained elevated in 19 cases. In 5 of these 19 patients, disease progression or persistence was documented (to the lymph nodes in three and to the lungs in two). TgAb levels were higher in patients with persistent disease in comparison with those tumor-free. Serum thyroglobulin (S-Tg) results were only elevated in the two patients with persistent disease in the lungs. Our data suggest that TgAbs determination may give some additional information to the follow-up of patients with DTC: the disappearance of TgAbs after therapy seems to represent a favorable prognostic factor, while the persistence of circulating TgAbs, particularly at high levels and in the absence of detectable S-Tg, may be representative of disease.

Acute and chronic effects of high glucocorticoid levels on hypothalamic-pituitary-thyroid axis in man

It is known that glucocorticoids can influence anterior pituitary hormones other than ACTH. Their effects on the hypothalamic-pituitary-thyroid axis are controversial. To further investigate this issue, the acute and chronic effects of high plasma cortisol levels on TSH secretion were evaluated in 20 normal subjects and in 14 patients with Cushing's syndrome. In normals, high plasma cortisol levels were obtained by giving ACTH 250 micrograms or CRH 100 micrograms iv as a bolus or by an hydrocortisone 500 mg infusion over 1 h. Acute cortisol increase produced no effect both on basal and TRH-stimulated TSH secretion. In patients with Cushing's syndrome, basal TSH levels, low or suppressed, showed an impaired response to TRH, inversely correlated with urinary cortisol values. After successful surgery, TSH and its response to TRH became normal in concomitance with the normalization of plasma and urinary cortisol levels. Our data show the lack of an acute inhibitory effect of high plasma cortisol levels on TRH-TSH axis. However, after long-term exposure to high plasma cortisol levels, i.e. Cushing's syndrome, inhibition of both basal and TRH-stimulated TSH secretion was demonstrated. These findings indicate that only prolonged hypercortisolism does interfere with pituitary TSH secretion. The underlying mechanisms are still unclear.

Usefulness of the combined antithyroglobulin antibodies and thyroglobulin assay in the follow-up of patients with differentiated thyroid cancer

A total of 1050 patients with differentiated thyroid cancer (DTC) have been followed in the Thyroid Center of Padua by means of serum thyroglobulin (Tg) measured with IRMA method and anti-Tg antibodies (TgAb) assays. Circulating TgAbs were detected in 102 (9.7%) patients. In 32 of these 102, TgAbs were evaluated before and after total thyroidectomy and 131I ablation. In these patients no relationship was found between preoperative serum TgAb levels on the one hand and tumor stage at diagnosis or outcome of the disease on the other. During the follow-up, TgAb serum levels decreased or disappeared in 21 cases considered tumor-free, while they remained unchanged or even increased, in comparison with the preoperative ones, in 11 patients, 5 with proven metastases and 6 considered tumor-free. Evaluating the whole group of 102 TgAb-positive patients, we observed that TgAb serum levels, measured after thyroid ablation, were significantly higher in cases with metastases than in those considered tumor-free (653.0 +/- 196.9 vs 157.7 +/- 116.5 U/ml, m +/- SD, p less than 0.0001). In the group of patients with metastases and circulating TgAbs, Tg serum levels were elevated in 27% of cases on TSH-suppressive therapy and in 44% off therapy when nodal metastases were present, and in 67% of cases on TSH-suppressive therapy and in 83% off therapy when distant metastases were present.(ABSTRACT TRUNCATED AT 250 WORDS)

Severe hyperthyroidism due to metastatic papillary thyroid carcinoma with favorable outcome

A case of extremely severe hyperthyroidism due to bone metastasis of papillary thyroid cancer is described. Hyperthyroidism began in this patient soon after the discovery of pelvic metastasis and worsened after total thyroidectomy and after the first dose of radioiodine. The administration of methimazole, prednisone and multiple, fractioned and small doses of radioiodine cured the hyperthyroidism and stabilized the neoplastic growth. Hyperthyroidism lasted for at least six months and hypothyroidism appeared only after seven months. Thus, the fractionation of the doses of radioiodine together with antithyroid drugs appears to be an effective treatment in patients with hyperthyroidism due to metastatic thyroid cancer.

Clinical role of TSH binding inhibiting antibodies (TBIAb) assay

Anti TSH-receptor antibodies (TBIAb) were measured by a radioreceptor assay in 277 patients with Graves' disease, 101 with autoimmune thyroiditis, 43 with autonomous adenoma, 15 with subacute thyroiditis, 15 with euthyroid ophthalmopathy, 155 with euthyroid multinodular goiter, 10 with amiodarone-induced hyperthyroidism and 2 with tumoral TSH hypersecretion. TBIAb were present at high titers in 74% of patients with untreated or relapsed Graves' disease and, at lower titers, in only 10% of patients who had recovered from Graves' disease, in 8% of patients with autoimmune thyroiditis and in 4% of patients with euthyroid goiter. TBIAb were absent in normal subjects as well as in the other groups studied. These findings suggest that TBIAb represent a specific marker of Graves' disease, particularly of the untreated form. Their presence in non Graves' patients may be considered expression of inactive or inhibiting antibodies.

Severe hyperthyroidism due to neoplastic TSH hypersecretion in an old man

A case is reported of neoplastic TSH hypersecretion in a 62-year-old man with severe hyperthyroidism and cardiovascular disease. He had been known to be hyperthyroid for 14 yr, and had been treated by thyreostatic drugs and subtotal thyroidectomy without satisfactory results. When he was referred to our Center, he was frankly hyperthyroid with both TSH (14 microU/ml) and thyroid hormone serum levels (TT4 24 micrograms/dl, TT3 370 ng/dl, FT41 7.9) above the normal range. alpha-subunit serum level was markedly increased (7.2 ng/ml), while beta-subunit was only 0.3 ng/ml. Skull X-ray showed an enlarged sella turcica with destruction of the dorsum and an intrasellar tumor was visualized on conventional and computer tomography. TSH response was absent after TRH and domperidone, while TSH serum levels decreased by 25% after bromocriptine. Methimazole therapy temporarily decreased serum thyroid hormones to normal levels, while TSH levels rose to 34 microU/ml, thus indicating that pituitary-thyroid feed-back was maintained at a higher set point. Surgical attempt failed because of cardiac problems during anesthesia. Radiotherapy plus methimazole was begun and TSH serum levels first increased markedly, up to 140 microU/ml, and then progressively decreased without reaching normal values. After methimazole withdrawal hyperthyroidism recurred.

Long term thyroid function after subtotal thyroidectomy for Graves' disease

Between 1973 and 1980, 93 patients with Graves' disease underwent subtotal thyroidectomy by the same surgeon (the size of thyroid remnant was 4 g per side). No case of operative mortality, no case of thyroid storm nor of surgical complications occurred. Three months after surgery 40% of patients were euthyroid, 25% had overt hypothyroidism, 35% had subclinical hypothyroidism. In the following yr important variations of thyroid function were observed. The number of patients with subclinical hypothyroidism decreased slowly (22% and 9% at 3 and 6 yr, respectively), and some became euthyroid, some hypothyroid, others relapsed. Seven patients had recurrent hyperthyroidism. In particular at 3 yr 45% of patients were euthyroid, 28% had overt hypothyroidism, 22% had subclinical hypothyroidism, 4% had recurrence; at 6 yr 56% were euthyroid, 32% had overt hypothyroidism, 9% had subclinical hypothyroidism, 3% had recurrence. Four out of the 8 patients operated under 20-yr-old became hypothyroid in comparison with only 2 out of the 15 patients over 50-yr-old. Relapses were present only in patients operated at less than 40-yr and only in females. No correlation was found between thyroid lymphocytic infiltration and thyroid function after surgery, nor between the presence of antithyroid antibodies and hypothyroidism. All cases who relapsed had high TMA titers both before and after operation. This study confirms the need for accurate follow-up after subtotal thyroidectomy for Graves' disease.