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L Leenhardt

Publications and source records attributed to L Leenhardt.

28 records · Page 2Linked to original sources
PubMed1994

[Echography of thyroid nodules. The echography specialist facing the clinician's requirements].

The risk of malignancy in cases of unique non-functional thyroid nodules ranges from 5 to 20% and since definitive diagnosis can only be provided by the pathology examination, surgical removal could be planned in all cases. The clinician however also has the objective of proposing surgery to as few patients with benign nodules as possible and thus calls upon the echographist to help distinguish between malignant and benign nodules. Thus orders for echography carry an intrinsic request for diagnostic arguments, a precise analysis of the characteristics of the nodule and a description of possible multinodular dystrophy as well as an estimation of the probability of malignancy. The echographist's report must include a precise description of each thyroid lobe, the localization of the nodule, its size, contour, echostructure, echogenicity and calcifications. The cervical lymph node chains must also be explored. An analysis of the surrounding parenchyma can frequently confirm multinodular dystrophy. The size of the nodule is the determining factor in predicting malignancy. While for very small nodules, less than 1 cm in diameter, the malignant nature cannot be reasonably predicted, and inversely for very large nodules, invading an entire lobe, it is usually evident, for intermediate sized nodules, echography is a strategic diagnostic tool. No sign is pathognomonic but an association of arguments can favour malignancy: an unique isolated nodule, irregular contours, lymph node enlargement greater than 1 cm. Hypoechogenicity is another important characteristic with a positive predictive value of 50% to 63%. Overall, the sensitivity of echography is good at 75% with specificity of 61 to 83%.(ABSTRACT TRUNCATED AT 250 WORDS)

Humans↗
PubMed1994

[Flow cytometry of thyroid tumors. Study of fresh tissue in 50 patients].

OBJECTIVES: A measurement of cell DNA content would be highly useful in determining the malignant nature of thyroid tumours in cases without distinctive features such as metastases, capsule invasion or emboli. Abnormal cell ploidy can be recognized with flow cytometry, but it is not known whether such results have diagnostic value. We therefore compared--in a double blind prospective study--the results of flow cytometry and pathologic diagnosis in fresh tumoural and non-tumoural thyroid cells. METHODS: Fifty unselected cold thyroid nodules were obtained from 50 consecutive patients (40 women, 10 men; age 18-80 years; mean 46) who underwent surgery within a 6 month period. Surrounding non-tumoural tissue was also obtained in 46 of them. Cell ploidy and the percentage of cells in each cell phase was determined with flow cytometry for both tumoural and nontumoural tissues. Two pathologists, unaware of the flow cytometric results, independently established the histologic diagnosis according to the WHO classification. RESULTS: The pathologic diagnosis was carcinoma in 7 cases (papillary carcinoma 6, vesicular carcinoma 1) and benign adenomas in 43 (29 macrovesicular, 11 microvesicular, 3 oncocytal). All the non-tumoural tissue samples were diploid. All 7 carcinomas were diploid and 10 of the 43 benign adenomas were aneuploid (4 near-diploid, 3 hyperploid, 1 near-tetraploid, 2 multiploid). The mean proliferation index was increased in 5 diploid tumours. CONCLUSION: These findings confirm that cell ploidy measured by flow cytometry is of no diagnostic value in the thyroid gland. It was also revealed that aneuploidy in adenomas may be related to tissue rearrangements of undetermined prognostic significance.

Adenoma↗
PubMed1994

[Echography of thyroid nodules. What the clinician is waiting for].

Although modern high-resolution real time ultrasound equipment permits excellent visualisation of the thyroid nodules, their ultrasonic appearance and characteristics do not accurately predict the histological result. Ultrasound allows the whole thyroid and adjacent lymph nodes to be examined. It is regarded as valuable in differentiating between solid and cystic lesions and single or multiple lesions. But predictive positive values of ultrasound in suggesting malignant diagnosis is not so doubtful as it can be said. An hypoechoic lesion is more often malignant and it can be one criterion among many which can help clinician to select patients who must undergo surgery. Ultrasound guided fine needle biopsy is useful in these cases.

Diagnosis, Differential↗
PubMed1993

[Comments on the ultrasonographic evaluation of thyroid nodules].

Thyroid ultrasonography does not allow establishing a positive diagnosis as to the benign or malignant nature of a thyroid nodule. However, the predictive value of this technique should be studied on the basis of recent technological progress. The great power of resolution of current sonographic systems allows a fine semiological analysis of the features of nodules. Presumption factors such as the solid, hypoechogenic nature, predictive of cancer in 35 to 63% of cases according to series, can be gathered. Thus ultrasonography can be placed in its right place for decision in the diagnostic strategy for a cold nodule; this place is better than that of radionuclide scanning, and close to that of cytology. This technological progress involves an increase in the prevalence of thyroid nodules. Multiple infraclinical micronodules, visible on ultrasonography but with uncertain pathological significance, are demonstrated. While ultrasonography has a disputable predictive value in such cases, it still is the technique of choice for the surveillance of such nodules. Sonographic guidance of cytological puncture of thyroid nodules, doppler studies of nodule vasculature and computer-supported analysis of its texture are interesting capabilities that may allow increasing the diagnostic efficiency of thyroid ultrasonography.

Humans↗
PubMed1987

Effect of calcitriol in the control of plasma calcium after parathyroidectomy. A placebo-controlled, double-blind study in chronic hemodialysis patients.

Severe, prolonged hypocalcemia in observed in some, but not all, hemodialysis patients after parathyroidectomy performed because of uncontrolled hyperparathyroidism. The aim of the present study was to investigate whether calcitriol and calcium supplementation in the immediate period after parathyroidectomy (days 1-14) was of more help in the control of plasma calcium than calcium supplementation alone. Fourteen hemodialysis patients were enrolled in a prospective, randomized, double-blind and placebo-controlled study. From the day after parathyroidectomy, 7 patients received calcitriol and the remaining 7 a placebo using incremental doses adjusted to the degree of hypocalcemia (up to 4 micrograms/day for calcitriol). Plasma calcium, phosphorus, alkaline phosphatase and immunoreactive parathyroid hormone levels before parathyroidectomy were comparable in both patients groups, as was the lowest plasma calcium achieved after parathyroidectomy. The decrease in plasma calcium after parathyroidectomy was related to plasma alkaline phosphatase and to the number of osteoclasts and osteoblasts on bone biopsy surface before parathyroidectomy. The mean decrement of plasma calcium (days 3-9) as compared to that before parathyroidectomy was less pronounced in calcitriol-treated than in placebo-treated patients (0.25 +/- 0.06 versus 0.45 +/- 0.05 mM, mean +/- SEM, p less than 0.025). Treatment with placebo was interrupted before day 14 because of persistent severe hypocalcemia in 4 of 7 patients, whereas calcitriol treatment was continued in all 7 patients up to 14 days. Patients on calcitriol treatment required less mean calcium supplements (days 1-9) than patients receiving placebo (37.4 +/- 3.2 versus 49.4 +/- 3.7 g, p less than 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

Calcitriol↗