Structure et ultrastructure d'auto- et d'homogreffons thyroïdiens intratesticulaires chez le cobaye thyroïdectomisé

Résumé Des autogreffes et des homogreffes thyroïdiennes intratesticulaires ont été pratiquées chez le cobaye thyroïdectomisé. Trois mois après cette double intervention, les greffons ont subi une hyperplasie et une hypertrophie considérables. Au microscope optique l'image histologique de ce parenchyme thyroïdien implanté montre un aspect de très vive stimulation caractérisé par une élévation très nette de l'épithelium vésiculaire et une résorption intense de la colloïde. Ces mêmes greffons ont été étudiés au microscope électronique. L'ultrastructure des auto- comme des homogreffons est parfaitement conservée. Dans tous les cas on retrouve les attributs glandulaires caractéristiques de cellules thyroïdiennes vivement stimulées. Donc, ni le microscope optique, ni le microscope électronique ne permettent de différencier les homo- des autogreffons, alors que leur activité fonctionnelle est différente, puisque dans un travail antérieur les auteurs ont pu observer que les autogreffons thyroïdiens sont aptes à fixer plus d'¹³¹I que les homogreffons.Quoiqu'il en soit, il est possible de réussir, chez le Cobaye, des homogreffes d'adulte à adulte, sans traitement préalable de l'hote.

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Summary Intratesticular autografts and homografts of the thyroid gland had been performed on thyroidectomized guinea-pigs.Three months after this double intervention, the grafts underwent a considerable hyperplasy and hypertrophy. Under the light microscope, the histological picture of this implanted parenchyma shows a strong stimulation characterized by a clear increase of the vesicular epithelium and by an almost complete resorption of the colloid.The same grafts had been examined with the electron microscope. All the classical cytoplasmic organelles of the thyroid cells are perfectly conserved in the autografts as well as in the homografts. These grafted cells shows moreover all signs of a considerable hyperactivity of proteosynthesis and proteolysis.Neither the light microscope, nor the electron microscope made it possible to differentiate the homografts from the autografts. Whereas their functional activities are different: in fact the authors observed in a previous research that the thyroid autografts are capable of fixing more ¹³¹I than the homografts.Anyhow it is possible, in the Guinea-pig, to succeed homografts from one adult to another without preliminary treatment of the host.

     

Imagerie hybride (TEMP/TDM,TEP/TDM) et cancer différencié de la thyroïde

Differentiated thyroid cancer (DTC) is generally associated with a good prognosis. Local recurrences, mainly lymph-node involvement, account for 15–20% of cases and are surgically treated. Distant metastases, mostly in lungs and more rarely in bones, are present in 5% of patients. When iodine uptake is sufficient (in approximately 60% of patients), distant metastases can be destroyed by iterative activities of iodine 131. Serum thyroglobulin (Tg), which can be assessed either on hormonal treatment or on TSH stimulation is considered as the tumour marker in DTC. Functional (iodine 131 scintigraphy, FDG PET, bone scintigraphy) or anatomical (neck ultrasound, thoracic CT, bone MRI) imaging methods can be performed when Tg increases in order to show residual/recurrent disease. In recent years, new hybrid equipments integrating both a gamma camera and CT scan (SPECT/CT) have been commercialized while positron emission tomography cameras associated with CT (PET/CT) have been installed on the whole French territory. These equipments, which allow us to directly correlate functional and anatomical images, greatly improve the interpretation of planar scintigraphy or that of PET alone. Hybrid imaging enables us to precisely localize scintigraphic foci and most often, to immediately verify whether they correspond to tumour lesions. The aim of this article is to review the role of SPECT/CT and PET/CT in the management of patients with DTC in 2010.     

Détection scintigraphique préopératoire de métastases pulmonaires d’un carcinome vésiculaire de la thyroïde associé à une hyperthyroïdie

Preoperative accumulation of radioiodine in metastases of thyroid carcinoma and its association with hyperthyroidism are uncommon. We report a case of 58-year-old woman with follicular thyroid carcinoma revealed by thyrotoxicosis caused by a hot nodule, and bilateral pulmonary uptake of I-131 before total thyroidectomy. Despite four ablative doses of I-131, bone metastases were identified and the patient died 42 month after the initial diagnosis.     

Métastase du tissu mou révélant un carcinome folliculaire différencié de la thyroïde

Differentiated thyroid cancer occupies a very important place within the framework of thyroid pathology, representing 90% of thyroid cancers. A nodular goiter generally summarizes the clinical picture. Nevertheless, remote metastases can be revealing. The elective localizations of these metastases are by descending order of frequency: lung, bone, mediastinal lymph nodes, kidney, liver and adrenal glands. Soft tissue metastases are extremely rare and exceptionally revealing of the neoplasm. We report one case of follicular thyroid carcinoma revealed by soft tissue metastases of the arm.     

Principes de préparation et de congélation des spermatozoïdes testiculaires humains

The advantages and feasibility of human testicular spermatozoa cryoconservation for intracytoplasmic sperm injection (ICSI) have now been clearly demonstrated. However, the freezing protocol is based on empirical knowledge obtained from freezing of ejaculated spermatozoa. Testicular spermatozoa may not be fully mature gametes and may also be retrieved in only limited quantities. Little research has been conducted to determine whether they have the same cryobiological requirements as ejaculated spermatozoa. A better understanding of their cryobiological features and assessment of possible subcellular changes after thawing would help to optimize testicular preparations for cryopreservation (whole biopsies, seminiferous tubules, shredded suspension, single spermatozoa, etc.), freezing-thawing procedure, freezing media, and storage. Finally, there is a growing need for welldefined criteria (nuclear quality, etc.) to evaluate the tolerance of testicular spermatozoa to freezing-thawing procedure for ICSI     

Exploration biologique de l’auto-immunité thyroïdienne

Les maladies auto-immunes thyro?diennes se présentent selon un large éventail de manifestations cliniques qui s’étend de l’hypothyro?die par atrophie thyro?dienne à l’hyperthyro?die par maladie de Basedow (tableau 1). Le but de cette revue est de préciser, à la lumière de données récentes, les indications et les méthodes des dosages utiles au diagnostic des maladies auto-immunes thyro?diennes.     

Kyste du tractus thyréoglosse dégénéré révélant un microcarcinome papillaire multifocal de la thyroïde

The malignant degeneration of thyroglossal duct cyst (TDC) is a very rare phenomenon. It occurs 1% of operated cysts where papillary carcinoma represents the most frequent pathological type. The authors report a clinical observation of a papillary carcinoma of thyroid occurring in a thyroglossal duct cyst concomitant to a multifocal micropapillary thyroid discovered in a 21-year-old woman. A total thyroidectomy was performed. A complementary treatment by radioactive iodine 131 (3,7 GBq) was undertaken. Two years later, the patient is doing well and does not present any sign of recurrence. In the light of this observation, the authors propose to report the diagnosis and therapeutic aspects of degenerated thyroglossal duct cyst.     

Intérêt de la TEP/TDM au 18FDG dans les sous-types histologiques agressifs de cancers thyroïdiens (oncocytaire et peu différencié)

IntroductionThe objective of our study was to evaluate the performance of ¹⁸FDG PET/CT in aggressive histological subtypes of differentiated cancer of the thyroid and its therapeutic impact.MethodThirty-three patients (22 Hürthle cell carcinoma and 11 poorly differentiated carcinoma) who underwent FDG PET/CT were retrospectively included. Nine scans have been performed for initial staging, 16 for suspicion of recurrence (with 11 having a rising Tg), 3 for the reassessment of metastatic disease under systemic treatment and 30 systematically during follow-up. The results of PET/CT were confronted with histological data and follow-up results.ResultsThirteen out of 18 positive scans were confirmed (8 locoregional recurrences and 5 distant metastases). The majority of them were performed for a suspicion of recurrence (8) or for initial staging (2). The sensitivity, specificity, PPV, and NPV were respectively 81.2%, 88.1%, 72.2% and 92.5%. For Hürthle cell carcinoma and poorly differentiated carcinoma, the sensitivity and specificity were respectively 100% vs. 57% and 86% vs. 93%. Systematic PET scans were most of the time negative (26/30) and in accordance with histological and follow-up results. It was the same in case of scans performed for undetectable initial Tg (16/22). PET/CT modified patient management in 14% of the cases.ConclusionThis study confirms the good performances of ¹⁸FDG PET/CT for initial staging and in case of elevated Tg during the follow-up of aggressive histological subtypes of thyroid cancer. It does not seem relevant in the absence of a suspicion of recurrence or in the case of undetectable initial Tg.     

Aspects épidémiologiques du cancer différencié de la thyroïde (médullaire exclu) au Maroc

Epidemiology of thyroid carcinoma is a complex issue. Data on thyroid carcinoma incidence depend on the efforts undertaken through screening and on the diagnostic methods employed. The objective of this work is to carry out an epidemiologic approach of differentiated thyroid carcinoma (DTC) in our country, with an evaluation of the recent review of literature. This work consists of a retrospective analysis of 3144 cases of differentiated thyroid carcinoma followed in nuclear medicine department of Ibn Sina hospital in Rabat over a period of 20 years. Epidemiology has allowed us to study the influence of gender, age, tumour size, pathological type and prognosis factors in DTC. Epidemiological studies contribute to a better understanding and management of thyroid carcinoma. Further studies are mandatory to determine risk factors and elucidate pathogenetic mechanisms of DT.     

Métastases gingivales d’un carcinome thyroïdien différencié

The differentiated thyroid carcinoma metastases concern habitually the lymphatic chains, the bone, the lung, and to a lesser degree the other organs. We report a rare case of gingival metastasis of differentiated thyroid carcinoma with bony invasion, in a 50 year-old patient, in whom the gingival metastasis revealed the thyroid carcinoma. Such extension follows a protracted course. Metastasis clinically appears years after the diagnostic of initial tumour. The lack of any specific sign, makes them to be mistaken for inflammatory or infectious pathologies. Their prognosis is in general good, if they are early and accurately diagnosed.     

Cancer différencié de la thyroïde métastatique à propos de 70 cas : impact des nouvelles recommandations de 2017

IntroductionMetastatic differentiated thyroid carcinoma (MDT) represents an average of 10% of patients with CDT. Metastases are prognostic factors. Their care is multidisciplinary.ObjectiveTo study the epidemiological, clinical, histological, therapeutic and evolutionary aspects of metastatic CDT and to study the impact of new recommendations.Patients and methodsRetrospective study of 70 patients followed for a metastatic CDT collected between June 2007 and June 2017, in the nuclear medicine department of Hassan II University Hospital of Fez.ResultsMean age 51.34 ± 15.96 years, sex ratio F:H: 2.5. Age > 45 years old at 65.7% of whom 42.8% > 55 years old. Circumstances of discovery: nodule 15.8%, multi-hetero-nodular goiter 17.1%, metastases 65.7%. Multivariate analysis shows a significant correlation of age greater than 45 years (P: 0,001) and revealing metastasis. Histology: papillary carcinoma 72.9%, vesicular carcinoma 22.8% and carcinoma poorly differentiated 4.3%. Tumor > 4 cm in 45.7%, the TNM classification (2010) vs. TNM classification (2017): 31.4% vs. 48.6% in stage I, 12.9% vs. 28.6% in stage II, the stage III in 17.1% vs. 0% and 38.6% vs. 22.8% in stage IV. Complementary investigations: localization of metastases: 40% at the bone level, 31.4% lung, 14.3% ganglionnaires and others 9.9%. Hormonal braking treatment was administered in all patients and the « irathérapie » (ATA vs. French recommendation 2017).EvolutionSeven cases of cure, 1 case of recurrence, 4.3% refractory to iodine.ConclusionThe presence of metastases, worsens the prognosis. Therapeutic de-escalation with French recommendations. Bone localization was predominant, its management is multidisciplinary, and radioactive iodine as a complementary treatment does not allow their healing.     

Nodule thyroïdien bénin fixant le 99mTc-MIBI

ObjectivesTo illustrate a case of intense uptake of ^99mTc-MIBI on benign thyroid nodule and to recall the mechanisms of this uptake.Case presentationA patient of 25 years old had a parathyroid scintigraphy for suspected right lower parathyroid adenoma. The exam showed intense uptake of ^99mTc-MIBI at the infero-lateral region of the right thyroid lobe. Low levels of PTH prompted to perform a thyroid scintigraphy for better diagnostic orientation. The scan revealed a large cold right basilobar thyroid nodule. The patient underwent a right loboisthmectomy. The histological analysis found a 3 cm diameter vesicular adenoma with oncocytic cells of the lower pole of right thyroid lobe.Discussion/conclusion^99mTc-MIBI is used in the imaging of hyperparathyroidism. Radiotracer uptake is correlated to the parathyroid adenoma content in oxyphil cells. These cells are rich in mitochondria and retain the ^99mTc-MIBI. This radiotracer can bind also on thyroid nodules. The specificity of this uptake for the diagnosis of malignancy is low. It is relevant to the nodule's wealth in oncocytic cells. These cells possess numerous mitochondria and can sequester ^99mTc-MIBI like parathyroid oxyphil cells.     

Anticorps anti-spermatozoïdes: techniques de dépistage et interprétation des résultats

Since the first publication on the detection of sperm-agglutinating antibodies in infertile men, multiple assays have been described. The most useful tests are able to detect antibodies bound to the sperm membrane of motile spermatozoa. The immunobeads test (IBT) is considered to be the most advantageous in terms of its sensitivity, the low incidence of false-positive results, and its ability to localize antibodies of different immunoglobulin classes on the sperm surface. The IBT assay can be used in parallel with the mixed antiglobulin reaction (MAR), to detect sperm-associated antibodies in the ejaculates of infertile men, the most rational way to test for antisperm antibodies (ASA) in males. In view of the high level of agreement between the two assays, MAR, the easier of the two, may be used as a first step in the detection of these antibodies. A positive MAR must be confirmed by IBT, as this assay is more specific for the detection of IgA antibodies. The clinical significance of sperm-associated antibodies is usually established according to the proportion of motile spermatozoa coated with immunobeads, its class and its localization on the sperm surface. However, binding of immunobeads does not provide any information about the antigens against which the antibodies are directed. As the functional effects of sperm-associated antibodies may vary as a function of their antigenic specificities, other assays, using purified fertilization related antigens, are necessary to establish, for each individual, the specific impact of the antibodies on the fertilization process. The indirect IBT assay has recently become the most widely used test to detect the various classes of ASA in serum and cervical mucus of infertile women and in the serum and seminal fluid of infertile men, in combination with the direct assay described above. However, in most laboratories, it is performed with only one dilution of the biological fluid tested, usually a low dilution, so that antibody levels of no significance for fertility could be detected. This may explain a recente debate (Human Reprod, 1999) on the significance of ASA as a cause of infertility. At present, and in the absence of standardized assays able to identify the antigens involved in each individual immune reaction, antibody assays, as detected by the IBT assay, in the serum and/or genital secretions of infertile subjects might provide useful clinical guidance.     

Mensurations échographiques de la thyroïde chez des enfants de zéro à 15 ans de la ville de Ouagadougou

Among the methods used to carry out measurements of thyroid, echography is the best because it is noninvasive and more specific. The goals of this study were to determine the normal thyroid volume of the Burkinabe child; to study the parameters which induce a variation of thyroid volume and to compare our values with those from other localities. Through a cross-sectional study, 240 children from the town of Ouagadougou benefited from a thyroid echography. Thus the height (h), the transverse diameter (dt) and the thickness (e) were measured. Volume (vl) of each lobe was estimated by: vl = h × dt × e × 3.14/6. The total volume (VT) is the sum of the volumes of each lobe, the isthmus being neglected. A correlation set at the threshold p < 0.001 has been carried out between VT and some anthropometric parameters. The following averages were observed: before one year, the average volume is of 0.51 L ± 0.21; from one to three years, it is of 0.95 mL ± 0.33; from four to six years, the average volume is of 1.35 mL ± 0.43; from seven to nine years, it is of 1.95 mL ± 0.62. From 10 to 12 years, the average volume is of 3.01 mL ± 1.08 and it is of 5.32 mL ± 2.07 from 13 to 15 years. It stands out that the VT is positively associated with the age (r = 0.82), with the size (r = 0.73), with the weight (r = 0.81) and with body surface (r = 0.78). Moreover, the VT is higher among boys than in girls beyond one year of age. This parameter varies according to the area of origin. Lastly, compared with the American, European and Asian averages, our values are smaller. This study enabled us to establish our own standards which we will be able from now on to use in daily practice. However, multicentric studies associated with thyroid and sexual hormones blood levels measurements must be undertaken to ascertain these data.     

„Cellules de thyroïdectomie“ et „cellules de castration“ chez la Caille japonaise,Coturnix coturnix japonica

Résumé On compare l'ultrastructure et la localisation des phosphatases acides au niveau des cellules hypophysaires delta et beta, chez des Cailles mâles thyroïdectomisées et maintenues en photopériode courte ou bien castrées, puis placées en photopériode longue. On étudie en outre, dans ces deux cas, les effets d'injections de doses croissantes de thyroxine.La thyroïdectomie provoque la transformation des cellules delta en cellules de thyroïdectomie groupées en îlots à la périphérie du lobe céphalique. Ces cellules sont pauvres en phosphatases acides. La thyroxine (10 g/j pendant 2 jours) provoque la régression de ces cellules et l'apparition de lysosomes. Les cellules beta ne sont pas modifiées par la thyroïdectomie.La castration-photostimulation stimule les cellules beta localisées dans le lobe céphalique. Elle provoque dans les deux lobes de la glande l'hypertrophie et la vacuolisation des cellules delta qui se distinguent des cellules de thyroïdectomie par la présence de nombreux lysosomes. La thyroxine freine simultanément l'activation des cellules delta et des cellules beta, en provoquant la formation de lysosomes, mais la dose efficace chez le mâle photostimulé (20 g et 60 g/j pendant 5 jours) est sans effet chez le castrat photostimulé (dose efficace 180 g/j).Pour interpréter ces faits, on admet que les cellules delta, thyréotropes et les cellules beta, gonadotropes, seraient simultanément soumises à un contrôle freinateur des hormones thyroïdiennes et des stéroïdes mâles.

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Thyroidectomy cells and castration cells in the Japanese quail, Coturnix coturnix japonica Ultrastructure and cytoenzymology

Summary The ultrastructure and the localization of acid-phosphatase activity are compared in beta and delta pituitary cells of male Japanese quail, either thyroidectomized and maintained in short days, or castrated then put in long days. Moreover, in these two cases, the effects of brief treatments with increasing doses of thyroxine are studied.Thyroidectomy induces transformation of delta cells into thyroidectomy cells arranged in clumps at the periphery of the cephalic lobe. The acid-phosphatase activity of such cells is low. Thyroxine (10 g per day for two days) causes regression of these cells and the appearance of numerous lysosomes. Beta cells are not modified by thyroidectomy.Castration and exposure to long days stimulate beta cells, localized in the cephalic lobe. It induces, also, in both pituitary lobes, hypertrophy and vacuolization of delta cells which differ from thyroidectomy cells by the presence of numerous lysosomes.Thyroxine in photostimulated quail inhibits both delta- and beta-cell stimulation and increases the frequency of lysosomes but the effective doses on males (20 g or 60 g per day for five days) are inactive on castrates, the response of which is obtained with 180 g per day.In order to explain these data, a hypothesis is suggested: Thyrotropic delta cells and gonadotropic beta cells are both subject to a double inhibiting control by thyroid hormones and male steroids.

Nous remercions très vivement pour leur excellente collaboration technique Mme Renée Picart (préparation des tissus pour la microscopie électronique) et M. Claude Pennarun (photographe).     

Apport de l’iode 131 dans le traitement de l’adénome thyroïdien toxique

IntroductionToxic thyroid adenoma is an evolutive condition requiring radical treatment. The purpose of this study is to evaluate the contribution of 131 in the treatment of toxic thyroid adenoma.Patients and methodsThis is a retrospective study of patients treated with iodine 131 for toxic thyroid adenoma. The diagnosis of toxic adenoma is confirmed by scintigraphy and/or ultrasound. Data collected were age, sex, previous treatments, pre treatment hormonal status, radioiodine activity received and post therapy hormonal status.Results and conclusionWe have 45 women to seven men with a sex ratio of 6.42. Mean age of our patients is 53 years. Mean age for women at time of treatment is 57.33 years and 52.85 years for men. 98.07% of our patients treated with iodine 131 gained euthyroidism or became hypothyroid vs. 1.92% in whom hyperthyroidism persisted. These results are comparable to literature. Moroccan patients socioeconomic status pleads for an expansion of use of radioiodine in toxic thyroid adenoma due to its favourable cost/effectiveness ratio.