Coexistence of a parathyroid adenoma and parathyroid cyst causing primary hyperparathyroidism.

The association of a functional parathyroid cyst with a parathyroid adenoma is an uncommon finding. In this report we describe the clinical history of a 60-yr-old man, presenting with the following findings: hypercalcemia (18.9 mg/dl), elevated serum parathormone levels (1320 pg/dl), hypercalciuria (228 mg/dl), and hyperphosphaturia (155 mg/dl). Neck ultrasound, magnetic resonance imaging (MRI) and 99Tc Sestamibi scintigraphy led to the identification of a left parathyroid adenoma, located at the lower pole of the left thyroid gland lobe, associated with a parathyroid cyst, located at the upper extremity of the same thyroid lobe. Parathyroidectomy was performed and the histological examination confirmed the diagnosis of a parathyroid adenoma with aspects of cystic degeneration and an upper parathyroid cyst. Analysis of the crystal clear intracystic fluid showed elevated parathyroid hormone (PTH) levels (137.000 pg/ml). The patient is normocalcemic at 2 yr after surgery without signs of recurrent parathyroid enlargements. Aetiology, diagnosis and management of parathyroid cyst will be discussed.

Age-related prevalence of platelet-associated immunoglobulins G in nonthrombocytopenic patients with autoimmune thyroid disease and autoimmune polyglandular syndrome.

OBJECTIVE: The prevalence of platelet-associated IgG (paIgG) in nonthrombocytopenic patients with autoimmune thyroid disease (AITD) alone or associated with autoimmune polyglandular syndrome (APS) has been studied. SUBJECTS: A total of 164 individuals were enrolled in this study: 81 patients with AITD alone, 33 patients with APS, and 50 healthy controls. RESULTS: The presence of paIgG was recorded in 41 of 81 patients with AITD (51%) as compared with 2 of 50 control subjects (4%, p < 0.0001). The prevalence of paIgG in patients with APS was higher even when compared with patients with AITD alone (25/33, 76%; p = 0.02). The presence of paIgG was not related to the functional thyroid parameters. The prevalence of paIgG was higher in the older than in the younger patients (75 vs. 47%, p = 0.0037). CONCLUSIONS: The results indicate that the prevalence of paIgG in patients with AITD is higher than previously thought, namely in elderly patients and in patients with APS, and not related to the thyroid function.

Hyperthyroidism with concurrent thyroid cancer.

The occurrence of thyroid malignancy is considered a rare event in hyperthyroid patients. With the aim of assessing the clinical relevance of this association, we have analyzed the incidence of thyroid cancer in hyperthyroid patients treated by surgery. The incidence of thyroid cancer was retrospectively evaluated in 202 hyperthyroid patients who underwent thyroidectomy during a twenty-year period. A thyroid cancer was diagnosed in 12 cases (5.9 per cent). Histologic examination revealed the presence of papillary carcinoma in 9 cases, follicular carcinoma in 1 case and Hürthle cell carcinoma in 2 cases. The association between thyroid cancer and hyperthyroidism was more frequent in toxic adenomas (17.8 per cent) than in toxic diffuse (5.3 per cent) or multinodular goiters (1.7 per cent). In 8 patients they presented as an occult carcinoma (maximum diameter below 1 cm), but unfavourable histologic features, such as local invasiveness and multifocality, were found in 5 of them. Follow-up data indicate that all 12 patients are currently alive and apparently free of disease. Hyperthyroid patients, particularly those affected by toxic adenomas, should be carefully evaluated to exclude the presence of concurrent malignancy. A special attention should be made moreover to the presence of "occult" lesions that, in our study was characterized in a higher proportion (62.5 per cent) of cases, by unfavourable histologic features.

Clinical and laboratory follow-up in differentiated thyroid carcinoma.

Thyroid carcinoma is the most frequent endocrine malignant neoplasm even if a rare occurrence (0.5%-1.0%) of all human malignant tumors. Primary differentiated (papillary and follicular) forms represent over 90% of the total. Since recurrence of thyroid carcinoma can occur even after several years, patients must undergo a life-long follow-up. Thyroglobulin, being organ-specific, plays a major role as tumor marker and it is used essentially in the monitoring and follow-up of patients with differentiated thyroid carcinoma, both during L-thyroxine suppressive therapy and when it is discontinued or after recombinant TSH administration. The presence of antithyroglobulin antibodies masks the real value of thyroglobulin and therefore, at the same time, antithyroglobulin antibodies should always be determined.

Molecular genetics of benign thyroid disease.

Thyroid diseases include forms amenable to alterations in genes involved in functional regulatory processes, morphofunctional development, hormogenesis and hormone functional expression. A number of genetic diseases are consequent of a point mutation, the cause of the replacement of a single nucleotide which may alter the chromosome number structure and morphology. Among structural anomalies there is deletion, duplication, inversion, translocation and isochromosome formation. Among thyroid diseases, the underlying cause of some of them is represented by alterations in genes regulating the thyroid function, alterations in genes of thyroid differentiation. Less common are the alterations in genes connected with the synthesis of proteins involved in hormone transport while alteration in genes encoding thyroid hormone receptors and in genes involved in thyroid neoplastic transformation are extensively described in literature. The studies of molecular biology will allow in-dept knowledge of the pathogenesis of thyroid disease associated to genetic alterations.

Prevalence of thyroid cancer in hyperthyroid patients treated by surgery.

A retrospective study has been carried out to evaluate the prevalence of malignant thyroid tumors in 202 patients submitted to surgery for hyperthyroidism. Thyroid cancer was diagnosed in 12 cases (5.9%); the final histologic examination revealed nine papillary carcinomas, one follicular carcinoma, and two Hürthle cell carcinomas. Concurrence of hyperthyroidism and thyroid cancer was more frequent in patients with single toxic adenomas than in those with toxic diffuse or multinodular goiters. In five cases thyroid malignancy was detected in the context of the hyperthyroid lesion (three toxic adenomas and two diffuse goiters). In eight patients the malignant lesion showed a maximum diameter of less than 1 cm, although in five of these cases unfavorable histologic features, such as minimal capsular invasion or multifocality, were present. All patients presenting with thyroid cancer are currently alive and apparently free of residual disease. It is concluded that hyperthyroid patients, particularly those with single toxic adenomas, should be carefully evaluated to exclude the presence of an associated malignancy and to plan the most appropriate therapeutic options.

Diagnostic accuracy of conventional versus sonography-guided fine-needle aspiration biopsy of thyroid nodules.

Fine-needle aspiration biopsy (FNAB) is an accurate, slightly invasive, and safe method for the preoperative diagnosis of thyroid nodules. Recently, ultrasound guidance has been suggested as a valuable aid to enhance FNAB diagnostic performance. In this study, we have compared diagnostic accuracy of conventional FNAB (C-FNAB) versus sonography-guided FNAB (SG-FNAB) on a large sample population of 9683 patients with thyroid nodules. Over a 15-year period, 4986 patients were investigated by C-FNAB and 4697 underwent SG-FNAB. A valid cytological diagnosis was obtained in 85.9% of C-FNAB and in 91.5% of SG-FNAB cases, allowing detection of thyroid cancer in 1.6% and 2.1% of patients, respectively. The indeterminate pattern of follicular neoplasia was observed in 238 C-FNAB (5%) and in 272 (5.4%) SG-FNAB nodules. Specimens were cytologically inadequate in 433 C-FNAB (8.7%), but only in 167 SG-FNAB cases (3.5%). A total of 535 C-FNAB and 540 SG-FNAB nodules underwent surgery. False-negative results occurred in 7 C-FNAB nodules (2.3%), but only in 3 SG-FNAB cases (1%). Sensitivity, specificity, and global diagnostic accuracy of C-FNAB compared with SG-FNAB were 91.8% versus 97.1%, 68.8% versus 70.9%, and 72.6% versus 75.9%, respectively. Our results, based on a large population of thyroid nodules, demonstrate that SG-FNAB allows a more precise and adequate sampling of thyroid nodular lesions and is associated with a lower rate of false-negatives, thus improving global diagnostic accuracy in the preoperative selection of thyroid cancer.

Diagnosis of thyroid carcinoma.

Despite being one of the most frequent neoplasms occurring in the endocrine system, thyroid carcinoma is, nevertheless, a relatively rare event (0.5-1.5% of all malignant tumours in man); the differentiated forms are the most prevalent and are characterized by a high mean survival rate, whereas the very aggressive forms are rare and prognosis is unfavourable. Diagnostic evaluation of carcinomatous lesions, particularly in the early stages, may give rise to considerable difficulties at a clinical level due to the differentiation of the benign lesions, which are a frequent finding. The traditional clinico-semeiological and instrumental parameters, which, in the past, were used in the assessment of suspected malignancy, should not be considered as markers of malignancy; however, exposure to ionizing radiations during childhood may have a well defined role of risk. Following the recent progress in genetic and molecular studies, it is now possible to exploit genetic-molecular tumor markers and, at present, thyroid medullary carcinoma may be identified also in the absence of clinical evidence, particularly the familial form, thus allowing suitable prophylaxis in those subjects with specific genetic impairment (e.g. preventive thyroidectomy in infancy). Since no discriminating clinico-semeiological parameters are available, considering the aspecificity of scintigraphic findings and the lack of reliability of echographic imaging in providing data which enable us to distinguish a rare neoplastic pattern from the more frequent finding of a benign thyroid mass, fine-needle aspiration (FNA) cytology may today be considered the technique of choice in the screening of the thyroid nodule. Our experience in over 12,000 nodular lesions since 1982, has confirmed that the cytological examination is the most discriminating investigation, diagnostic reliability being far greater than that of traditional techniques. Considering the high frequency of thyroid nodule disease which rarely harbours a carcinomatous lesion, a very scrupulous diagnostic algorithm is mandatory. The FNA cytology, together with morphofunctional and immunological examinations, as well as dynamic exploration of the thyroid hypothalamo-pituitary axis, which allows a nosographic picture of the thyroid nodule disease, provides a more discriminating appraisal for the surgical approach to a single, solitary or prominent nodule.

[Clinical significance of Hürthle cell in the cytology of thyroid disease]. / Significato clinico della cellula di Hürthle nella citologia tiroidea.

The natural history of Hürthle cell (HC) lesions has been the focus of a considerable debate. The difficulties in defining the malignant potential of HC has led to the current designation of HC tumor, with the implication that it may behave as either a benign or a malignant lesion. The objective of our study was to verify the clinical and prognostic relevance of the cytological diagnosis of HC in the thyroid lesion, 10,950 consecutive patients (F/M = 5.6/1) with thyroid nodules were evaluated by means of fine needle aspiration biopsy (FNAB). Cytological diagnosis showed the presence of HC in 285 cases (2.6%), with a F/M ratio of 8.2/1. In 123 cases (43.2%) cytologic diagnosis resulted benign. A suspicious pattern of follicular neoplasm was observed in 159 cases (55.8%). Only in 3 cases (1%) thyroid carcinomas were preoperatively identified. No false positive or negative cases were observed. Among the HC lesions, 85 patients (29.8%) underwent thyroid surgery because of a malignant or suspicious cytologic diagnosis, continuous nodular growth despite LT4 therapy, mechanical compression or clinical judgement. The other two hundred patients were clinically evaluated and, one year later, repeated FNAB confirmed the cytologic diagnosis of benignity. Among the follicular neoplasm nodules, 80 cases (55.3%) were surgically explored, and thyroid carcinoma diagnosed in 30 of them (37.5%), this percentage being greater than that observed in the group of non-HC follicular neoplasm (17%). Pathologic criteria for malignancy (vascular invasion, transcapsular penetration, destructive capsular invasion) were described in 25 out of all carcinomas.

Thyroid carcinoma in children and adolescents.

UNLABELLED: A clinical and pathological study was undertaken to define the prevalence, clinical presentation and outcome of thyroid carcinoma in children and adolescents. Clinical records from 48 patients under 20 years of age at diagnosis, out of 372 patients with thyroid cancer examined between 1980 and 1994, were retrospectively reviewed. Female/male ratio was 3.8/1. None had a previous positive history of head and neck irradiation. Patients underwent near-total (44 patients) or partial (4 patients) thyroidectomy followed by 131I ablation of residual thyroid tissue. The mean follow up period was 58.4 months, ranging between 2 and 190 months. Clinically a thyroid mass was present in 41 patients, 28 of whom also showed neck lymph node involvement. Node metastases were present in 50% of the patients and lung metastases in 4.2%. Histological type was papillary in 41, follicular in 6, and medullary in 1 case. Surgical complications were observed in 19 patients (40%). In 3 patients papillary thyroid cancer was associated with chronic lymphocytic thyroiditis. All patients were treated with 1-thyroxine suppressive therapy. Recurrences of cancer after surgical and radio-iodine treatment was observed only in one patient 8 months after surgery. CONCLUSION: Our experience demonstrates that thyroid carcinoma in childhood cannot be considered a rare occurrence, since it represents about 13% of all thyroid cancers, and is frequently associated with lymph node but rarely with distant metastases. Nevertheless, the prognosis of thyroid carcinoma in childhood is fairly good.

Subclinical hypothyroidism in flight personnel: evaluation for suitability to fly.

NASA: A group of 3,324 Italian flight personnel were examined to test the usefulness of TSH assay as a screening test for subclinical hypothydroidism. Forty-two individuals with low serum T4 and high free T4 had further thyroid function tests. High TSH levels were found in 14 individuals, seven of whom were started on levothyroxine. Four individuals also had titers of antiperoxidase antibodies greater than 1:1,000 U/ml; three of these individuals were over age 65. TSH screening is deemed useful in the selection of flight personnel and determination of suitability to fly.^ieng

[Post-operative hypothyroidism]. / L'ipotiroidismo post-chirurgico.

Hypothyroidism is not a rare condition, since it represents about 10% of thyroid diseases. It is more frequent in women (F/M = 5/1), and in patients older than 60 years of age. Postoperative hypothyroidism is secondary to thyroidectomy, and the incidence varies, with a reported range between 14% and 75%. This may be related to the amount of thyroid removed, the experience of the surgeon, age of patient, the function of remaining thyroid, and duration of postoperative observation. The analysis of our cohort of more than 23,000 thyroid patients showed a prevalence of hypothyroidism of 11.1%. Postoperative hypothyroidism represents about 39.7% of all hypothyroid cases, and 44% of patients underwent surgery. The prevalence is six fold higher in patients over the age of 60. Factors favoring development are the presence of lymphocytic infiltration of the thyroid and a positive serological test for thyroid antibodies. Overt hypothyroidism represented the largest proportion, prevailing in 60% of postoperative hypothyroid patients. In view of the insidious development of postoperative hypothyroidism in some patients, an accurate follow-up should be required, allowing an opportune treatment with LT4.

[The autonomous nodule. Clinical aspects]. / Il nodulo autonomo. Aspetti clinici.

Autonomously functioning thyroid nodule (AFTN) includes a wide spectrum of unique or multifocal diseases, either hyper or euthyroid, which share the same independence from thyroid stimulating hormone (TSH) regulation in terms of growth and function. The pathological basis and the recent molecular implications of the disease are briefly discussed. Clinical and epidemiologic data of 1572 patients with AFTN, out of a population of 14107 patients with thyroid diseases, sequentially evaluated from 1974 to 1992, have been retrospectively examined. The mean age of AFTN occurrence is 41 years and it appears more frequently in women (F/M = 5.3/1). Clinical hyperthyroidism occurs only in 17% of patients and is more frequently observed in men over 40 years of age. The presence of sonolucent area inside the nodule is detectable in 8.6% of cases and may be associated with spontaneous arrest of growth. When AFTN is submitted to cytologic evaluation, patterns similar to those observed in nodular goiter are shown (colloid lesion, cyst and nodular hyperplasia). Signs of hyperactivity are also shown by follicular cells. In the presence of a cyst, a fine needle aspiration was performed and a complete resolution was observed in 40% of cases. When cyst recurred after aspiration, a solution of tetracycline was inserted into the cavity. Sclerosing therapy was efficient in evacuating the volume of the nodule in 50% of the cases. Patients with AFTN were followed for a mean period of 61 months and 84.7% of them did not show any morphological or functional change, while the remaining 15.3% of cases became hyperthyroid.(ABSTRACT TRUNCATED AT 250 WORDS)

[The thyroid nodule. Diagnostic considerations]. / Il nodulo tiroideo. Considerazioni diagnostiche.

Thyroid nodule is extremely common. Its prevalence has been estimated to be more than 5% in the adult population. If thyroid nodule is a rare condition, 0.004% a year, identifying those nodules, which are likely to be malignant, is very important for physicians. The evaluation of thyroid is carried out using the fine needle aspiration biopsy (FNAB), the ultrasonography, and scanning with 131I and 99Tc. Before FNAB thyroid scans was the most common test in clinical evaluation of thyroid nodules, used to identify "hot" and "cold" lesions. Hot or warm nodules, about 5%, are seldom malignant, whereas cold or hypofunctional have a 10% to 25% chances of being malignant. FNAB is the elected laboratory test: this procedure is easily, simple, non traumatic, and very acceptable to the patients. Ultrasound is useful in several settings: it provides a non invasive and relatively inexpensive means of following the size of nodule, after medical therapy and FNAB.

Circadian rhythmicity of plasma amino acid variations in healthy subjects.

The circadian periodicity of plasma amino acids (AA) was explored using Cosinor analysis. Six healthy subjects eating a standard diet (30 Kcal and 1 g of protein/Kg of body weight) were studied. Plasma samples for AA determination were taken at 07:00, 11:00, 15:00, 17:00, 21:00 and 24:00. The majority of AA showed an increment in the evening samples. This 24-h variability led to a circadian rhythmicity for all AA, except for taurine, threonine, glutamate, alanine, cystine, and total tryptophan. On average, the fluctuation was approximately 15% of the mesor and the acrophase timing was between 17:00 and 22:00.

Usefulness of twenty-four-hour blood pressure patterns and response to short-term sodium restriction in normotensive subjects in detecting a predisposition to systemic arterial hypertension.

Twenty clinically healthy subjects were studied to identify normotensive adults with a predisposition to arterial hypertension by monitoring blood pressure (BP) and restricting dietary sodium intake. Short-term restriction in sodium intake resulted in a decrease of the mean level for the circadian rhythm of BP. The phenomenon is visible in subjects without familial hypertension but not in individuals with a positive history for high BP. The response of the 24-hour BP patterns to abrupt sodium deprivation seems to be an indicator for discovering normotensive subjects at risk of developing arterial hypertension.