IS MEASUREMENT OF CIRCULATING TUMOR DNA OF DIAGNOSTIC USE IN PATIENTS WITH THYROID NODULES?

OBJECTIVE

Circulating tumor DNA (ctDNA), a subset of cell-free DNA (cfDNA), is a potential biomarker for thyroid cancer. We determined the performance of a ctDNA panel for detecting thyroid malignancy in patients with thyroid nodules.

METHODS

Sixty-six patients with thyroid nodules without a prior history of cancer enrolled in a prospective, 1-year study in which blood was drawn for ctDNA analysis prior to undergoing fine-needle aspiration biopsy (FNAB) of thyroid nodules. The ctDNA panel consisted of 96-mutations in 9 cancer driver genes. The primary outcome measures were the sensitivity, specificity, and positive and negative predictive values (PPV, NPV) of our ctDNA panel for the diagnosis of thyroid malignancy as determined by pathologic and/or molecular tissue examination.

RESULTS

Results from 10 subjects could not be determined due to inadequate volume or technical issues. The final classifications of the thyroid nodules were 13 malignant and 43 benign lesions. A KRAS G12V mutation was detected in the plasma of 1 patient with stage IVA papillary carcinoma whose tissue contained the same mutation. Two of the 43 patients with benign lesions also had ctDNA detected, giving a sensitivity of 7.7%, specificity of 95.35%, PPV of 33.33%, and NPV of 77.35%. There were no significant differences between benign or malignant lesions in cfDNA levels.

CONCLUSION

Neither cfDNA measurements nor our panel of ctDNA mutations are sensitive or specific enough to provide valuable information over FNAB. An expanded panel and the inclusion of proteomics may improve sensitivity and specificity for thyroid cancer detection.

ABBREVIATIONS

cfDNA = cell-free DNA; ctDNA = circulating tumor DNA; FNAB = fine-needle aspiration biopsy; NIFTP = noninvasive follicular thyroid neoplasm with papillary-like nuclear features.

Analysis of malignancy predictors for oxyphile thyroid tumors

PURPOSE

In contrast to other thyroid carcinomas it is difficult to establish a correct preoperative diagnosis for oxyphile carcinoma of the thyroid. In this study we looked for predictive malignancy factors in order to enable surgeons to choose operative treatment and to perform an adequate operation for each patient with an oxyphile neoplasm of the thyroid.

METHODS

In this retrospective study we have analyzed the medical files of all patients with oxyphile tumors of the thyroid operated between 1999 and 2008 in our institution. A total of 256 patients were included and divided into oxyphile adenomas (142) and carcinomas (114) on the basis of their definite histopathological diagnosis. The most important demographic and clinical characteristics were analyzed by univariate and multivariate logistic regression analysis.

RESULTS

Univariate analysis showed that male gender, thyroglobulin concentrations ≥300 ng/ml and tumor diameter >30 mm were significantly more frequent in patients with oxyphile carcinoma compared to patients with oxyphile adenoma, while coexisting Hashimoto thyreoiditis and positive AntiTPO antibodies appeared significantly less frequent in the carcinoma group. All variables with a p value <0.1 in the univariate test were subjected to multivariate regression analysis in which elevated preoperative thyroglobulin concentrations (≥300 ng/ml) was shown as the only independent predictive factor for oxyphile thyroid carcinomas (OR=5.88, 95% CI 2.78-12.05, p=0.001).

CONCLUSIONS

Preoperative thyroglobulin concentration is an independent predictor of malignancy for oxyphile thyroid carcinomas.

Higher body mass index and larger waist circumference may be predictors of thyroid carcinoma in patients with Hürthle-cell lesion/neoplasm fine-needle aspiration diagnosis

OBJECTIVE

High body mass index (BMI) has been found to be associated with raised thyroid cancer risk, particularly in women. We examined the associations for BMI and waist circumference (WC) with thyroid cancer risk among women with Hürthle-cell lesion/neoplasm (HLN) on fine-needle aspiration biopsy (FNAB) with the hypothesis that BMI and WC could guide the management of these challenging indeterminate lesions.

METHODS

This cross-sectional study included 224 women with HLN who underwent thyroidectomy. In all patients, TSH and thyroid auto-antibodies were evaluated, and thyroid nodule features were recorded. Patients were grouped according to BMI (<30 or ≥30 kg/m(2)) and WC (<88 or ≥88 cm). Relationships of thyroid cancer with BMI and WC were assessed using logistic regression analysis.

RESULTS

Mean weight, BMI (31·26 ± 5·1 vs 26·47 ± 5·9, P < 0·001), WC (98·23 ± 7·6 vs 86·18 ± 11, P = 0·001), and proportion of patients with high BMI (≥30 kg/m(2)) (65·9 vs 33·8%, P < 0·001) or large WC (≥88 cm) (84·1 vs 47·9%, P < 0·001) were significantly higher in malignant group compared to benign group. In regression analysis, BMI and WC significantly associated with existence of malignancy. Malignancy risk was 3·819-fold higher (95% CI: 2·068-7·054) in BMI≥30 kg/m(2) group compared to BMI<30 kg/m(2), which was independent of TSH and age. Large WC was also associated with increased risk (OR = 5·593, 95% CI: 2·736-11·434). Baseline tumour characteristics were similar according to BMI and WC groups.

CONCLUSIONS

A great BMI and large WC were associated with higher thyroid cancer risk in patients with FNAB diagnosis of HLN. Further studies are needed to use BMI or WC in the management of patients with HLN.

Serum thyroglobulin (Tg) monitoring of patients with differentiated thyroid cancer using sensitive (second-generation) immunometric assays can be disrupted by false-negative and false-positive serum thyroglobulin autoantibody misclassifications

CONTEXT

Reliable thyroglobulin (Tg) autoantibody (TgAb) detection before Tg testing for differentiated thyroid cancer (DTC) is critical when TgAb status (positive/negative) is used to authenticate sensitive second-generation immunometric assay ((2G)IMA) measurements as free from TgAb interference and when reflexing "TgAb-positive" sera to TgAb-resistant, but less sensitive, Tg methodologies (radioimmunoassay [RIA] or liquid chromatography-tandem mass spectrometry [LC-MS/MS]).

OBJECTIVE

The purpose of this study was to assess how different Kronus (K) vs Roche (R) TgAb method cutoffs for "positivity" influence false-negative vs false-positive serum TgAb misclassifications that may reduce the clinical utility of reflex Tg testing.

METHODS

Serum Tg(2G)IMA, TgRIA, and TgLC-MS/MS measurements for 52 TgAb-positive and 37 TgAb-negative patients with persistent/recurrent DTC were compared. A total of 1426 DTC sera with TgRIA of ≥ 1.0 μg/L had false-negative and false-positive TgAb frequencies determined using low Tg(2G)IMA/TgRIA ratios (<75%) to indicate TgAb interference.

RESULTS

TgAb-negative patients with disease displayed Tg(2G)IMA, TgRIA, and TgLC-MS/MS serum discordances (% coefficient of variation = 24 ± 20%, range, 0%-100%). Of the TgAb-positive patients with disease, 98% had undetectable/lower Tg(2G)IMA vs either TgRIA or TgLC-MS/MS (P < .01), whereas 8 of 52 (15%) had undetectable Tg(2G)IMA + TgLC-MS/MS associated with TgRIA of ≥ 1.0 μg/L. Receiver operating characteristic curve analysis reported more sensitivity for TgAb method K vs R (81.9% vs 69.1%, P < .001), but receiver operating characteristic curve cutoffs (>0.6 kIU/L [K] vs >40 kIU/L [R]) had unacceptably high false-negative frequencies (22%-32%), whereas false positives approximated 12%. Functional sensitivity cutoffs minimized false negatives (13.5% [K] vs 21.3% [R], P < .01) and severe interferences (Tg(2G)IMA, <0.10 μg/L) (0.7% [K] vs 2.4% [R], P < .05) but false positives approximated 23%.

CONCLUSIONS

Reliable detection of interfering TgAbs is method and cutoff dependent. No cutoff eliminated both false-negative and false-positive TgAb misclassifications. Functional sensitivity cutoffs were optimal for minimizing false negatives but have inherent imprecision (20% coefficient of variation) that, exacerbated by TgAb biologic variability during DTC monitoring, could cause TgAb status to fluctuate for patients with low TgAb concentrations, prompting unnecessary Tg method changes and disrupting Tg monitoring. Laboratories using reflexing should limit Tg method changes by considering a patient's Tg + TgAb testing history in addition to current TgAb status before Tg method selection.

Preoperative undetectable serum thyroglobulin in differentiated thyroid carcinoma: incidence, causes and management strategy

BACKGROUND

In recent years serum thyroglobulin (Tg) measurement during thyroxine (T4) treatment and/or after stimulation by endogenous TSH or recombinant human TSH (rhTSH) has eclipsed other diagnostic procedures in managing patients with differentiated thyroid cancer (DTC). However, preoperative undetectable Tg was reported in up to 12% of patients affected by DTC and recurrences of DTC with no increase in serum Tg have also been described. Clearly, a negative Tg measurement may falsely reassure both the patient and the clinician in these cases.

AIM

We retrospectively evaluated the incidence of undetectable or reduced preoperative serum Tg in a group of 436 patients affected by DTC. Additionally, we evaluated the role of Tg retesting by two different immunoassays in patients with low Tg at first measurement.

METHODS

We retrospectively selected 17 patients with undetectable (i.e. less than functional sensitivity of assay method) or reduced Tg (i.e. between functional sensitivity and minimum normal value) among 436 patients with histologically proved DTC. The remaining 419 patients were used as control cases. Frozen sera from all patients were retested by two different Tg immunoassays.

RESULTS

Globally, 17 out of 436 (3.8%) patients showed undetectable (n = 5, 1.1%) or reduced (n = 12, 2.7%) preoperative Tg. The Tg level was above the minimum normal value in 3 and 4 out of 5, and 8 and 9 out of 12 of these patients, respectively, when two different immunoassays were employed. On the other hand, undetectable or reduced Tg levels were found in 3.0%-5.1% of control cases when different immunoassays were used.

CONCLUSIONS

Regardless of the method employed, 3.0-5.1% of patients with DTC showed undetectable or reduced preoperative Tg. This fact must be recognized, as Tg cannot be used as a benchmark for DTC follow-up in these cases. However, Tg retesting with different immunoassays seems to be useful in ruling out these pitfalls in a large majority of patients, and also indicates the most effective assay to be employed in these cases.

Detection of carbonic anhydrase-9 gene expression in peripheral blood cells predicts risk of disease recurrence in patients with renal cortical tumors

OBJECTIVES

To present extended follow-up on a cohort of patients with renal cortical tumors treated with partial or radical nephrectomy and preoperatively assess for carbonic anhydrase 9 tumor marker expression in the peripheral blood.

METHODS

All patients were originally enrolled in an institutional review board-approved study assessing the role of a reverse-transcriptase polymerase chain reaction peripheral blood assay designed to detect the tumor-specific gene carbonic anhydrase-9 (CA9). A total of 41 patients with renal cortical tumors confined to the kidney were enrolled at a single institution and assessed preoperatively with peripheral blood test for CA9 expression before undergoing partial or radical nephrectomy. A Kaplan-Meier estimated survival analysis and log-rank test were performed to determine whether detection of peripheral blood cells expressing the CA9 gene influences disease-free and disease-specific survival.

RESULTS

The median follow-up was 4.3 years. The median age was 71 years. Of the 41 patients, 26 were men and 15 were women. The estimated 5-year disease-free survival for patients with detectible expression of the CA9 gene in the peripheral blood was 39.5% compared with 88.1% for patients without detection of the CA9 gene (P = 0.048). On bivariate analysis, disease-free survival correlated with histologic type, tumor diameter, and tumor grade.

CONCLUSIONS

The expression of the tumor-specific marker CA9 in the peripheral blood is associated with decreased disease-free survival in patients with renal cortical tumors. This is the first study reporting on the prognostic value of this peripheral blood-based tumor marker for kidney tumors.

Staging and treatment of differentiated thyroid carcinoma with radiolabeled somatostatin analogs

In patients with progressive metastatic (or recurrent) differentiated thyroid carcinoma that either do not take up radioiodine or are unresponsive to continued radioiodine therapy, staging is difficult and treatment options are few. However, in most of these patients uptake of radiolabeled somatostatin analogs is evident on somatostatin-receptor scintigraphy (SRS). Using SRS, patients with sufficient uptake of radiolabeled somatostatin analogs can be selected for high-dose peptide receptor radionuclide therapy (PRRT) as an alternative targeted-treatment option. PRRT with the beta-particle-emitting radionuclides (90)yttrium ((90)Y) and (177)lutetium ((177)Lu) gives the best results in terms of objective tumor response. Promising, novel, radiolabeled somatostatin analogs that have a broader receptor affinity profile and, thus, a potentially wider therapeutic range are being tested clinically.

Elevated basal calcitonin levels in a patient with a hurthle-cell carcinoma of the thyroid and neuroendocrine differentiation: report of a case

A thyroid nodule with elevated plasma levels of calcitonin is usually suggestive of a medullary thyroid carcinoma (MTC); however, thyroid and extrathyroid conditions have been reported with elevated plasma calcitonin levels in the absence of MTC. We report the case of a patient with a thyroid nodule and an elevated basal plasma calcitonin level of 315 pg/ml (normal value <100 pg/ml) who underwent a left hemithyroidectomy. Interestingly, histopathological examination revealed a Hurthle-cell carcinoma with positive neuroendocrine (NE) markers such as calcitonin and synapthophysin, but not with chromogranin staining. Thus, we discuss the phenomenon of non-NE tumors showing positivity for NE markers.

Factors influencing the basal and recombinant human thyrotropin-stimulated serum thyroglobulin in patients with metastatic thyroid carcinoma

The serum thyroglobulin (Tg) level is the most sensitive marker for detecting residual thyroid carcinoma. We hypothesized that the basal and TSH-stimulated Tg levels in patients with metastatic thyroid carcinoma would reflect tumor volume, histological subtype, and location of metastatic lesions. A retrospective review of 417 thyroid cancer survivors undergoing evaluation for residual disease with the assistance of recombinant human TSH (rhTSH) was performed. In 169 patients with metastatic disease, we found that the basal Tg level directly correlated with the number of lesions, and that it was highest in patients with follicular and lowest in those with papillary thyroid carcinoma. The basal Tg level was highest in patients with bone metastases and lowest in those with cervical metastases. The fold increase in the serum Tg after rhTSH treatment was highest in papillary thyroid carcinoma and lowest in Hurthle cell carcinoma. The fold increase in Tg was not influenced by tumor volume or by the site of metastatic lesions. Multivariate analysis showed multiple interactions between factors, but did not identify one factor that significantly influenced basal Tg or fold increase. We conclude that the location and volume of metastases influence basal Tg, but not its responsiveness to rhTSH, whereas the histological type of carcinoma influences both basal Tg and responsiveness to rhTSH.

Oxyphil parathyroid adenoma: a malignant presentation of a benign disease

Functioning parathyroid adenomas of the oxyphil cell type are rare, and the clinical characteristics of patients with these tumors have not been well defined. We describe two cases of severe primary hyperparathyroidism (PHPT) caused by benign oxyphil parathyroid adenomas. The patients' clinical presentations mimicked parathyroid carcinoma. Both had very large tumors associated with marked elevations in PTH and serum calcium levels. Skeletal manifestations were also atypical for benign PHPT, with severe osteoporosis in one patient and osteitis fibrosa cystica in the other. These cases also highlight the remarkable capacity of the skeleton to recover after successful parathyroidectomy, previously reported in other forms of severe PHPT. Bone mineral density improved dramatically 1 yr after parathyroidectomy, with increases of 51% at the lumbar spine, 36% at the total hip, and 11% at the distal one third radius. Most of the increases occurred in the first postoperative months. Consistent with this early and accelerated skeletal response, markers of bone turnover were increased 2 months after surgery and normalized by 8 months postoperatively. In patients with PHPT who present with severe or atypical clinical features, oxyphil adenoma should be considered.

Sonography in the diagnosis of cervical recurrence in patients with differentiated thyroid carcinoma

OBJECTIVE

To determine the sensitivity of thyroglobulin (Tg), iodine scanning, and sonography in the diagnosis of cervical recurrence of thyroid cancer.

METHODS

This prospective study assessed 81 patients with cervical metastases or extrathyroid invasion at first appearance who underwent clinical examination, scanning, measurement of Tg after thyroxine withdrawal, and sonography about 8 months after thyroidectomy followed by radioiodine treatment. Only patients without distant metastases and without anti-Tg antibodies were included.

RESULTS

Fifty patients showed persistence of the disease in the cervical region, with only 16% of them having had a suspicion on clinical examination, 33 with Tg levels of 2 ng/mL or greater (66% sensitivity), and 29 with positive scan findings (58% sensitivity). A combination of the 2 methods detected disease in 40 (80%) of 50 patients but failed to show 20% of cases that were identified by sonography and confirmed by fine-needle aspiration. Sonography had sensitivity of 96%. Specificity values for Tg, iodine scanning, and sonography were 80.6%, 90.3%, and 87%, respectively.

CONCLUSIONS

Classic follow-up methods may not detect cervical disease in some patients with differentiated thyroid carcinoma, and sonography is necessary even in patients apparently free of the disease.

Outcome in patients with differentiated thyroid cancer with negative diagnostic whole-body scanning and detectable stimulated thyroglobulin

BACKGROUND

Management of patients with differentiated thyroid carcinoma with negative diagnostic radioiodide scanning and increased serum thyroglobulin (Tg) concentrations is a widely debated problem. High-dose iodine-131 treatment of patients who have a negative (131)I diagnostic whole-body scan (WBS) is advocated. However, the therapeutic benefit of this "blind" treatment is not clear.

OBJECTIVE

To investigate the course of serum Tg during thyroid hormone suppression therapy (Tg-on) and clinical outcome in patients with negative diagnostic (131)I scanning and increased serum Tg concentrations during thyroid hormone withdrawal (Tg-off), after treatment with high-dose (131)I.

DESIGN

Retrospective single-center study.

METHODS

Fifty-six patients were treated with a blind therapeutic dose of 150 mCi (131)I. Median follow-up from this treatment until the end of observation was 4.2 Years (range 0.5-13.5 Years).

RESULTS

The post-treatment WBS revealed (131)I uptake in 28 patients, but none in the remaining 28 patients. In this study the Tg-on values did not change after treatment in either the positive or the negative post-treatment WBS group. During follow-up, 18 of the 28 patients with a positive post-treatment WBS achieved complete remission, compared with 10 of the 28 patients with a negative post-treatment WBS. Nine patients in the negative group died, but no patients died in the positive post-treatment group (P=0.001).

CONCLUSIONS

High-dose iodine treatment in diagnostically negative patients who have a negative post-treatment scan seems to confer no additional value for tumor reduction and survival. In patients with a positive post-treatment scan, high-dose iodine treatment can be used as a diagnostic tool to identify tumor location, and a therapeutic effect may be present in individual cases.

Lack of impact of radioiodine therapy in tg-positive, diagnostic whole-body scan-negative patients with follicular cell-derived thyroid cancer

Several reports have suggested a benefit from radioactive iodine (RAI) therapy in Tg-positive, whole-body scan-negative patients with follicular cell-derived thyroid cancer, who were said to have high rates of visualization of uptake in metastases after therapeutic doses of RAI. We sought to evaluate the rate of visualization of RAI uptake in these patients and determine the effect of such therapy on tumor progression and Tg levels. We studied 24 consecutive patients who had been treated with high-dose RAI, four of whom had no evidence of metastasis or persistent cancer. Our results showed that four patients had some uptake in posttherapy scans: in the neck, lung, and mediastinal metastases in one patient, in the thyroid remnant in two, and in a possible neck microrecurrence in one. In 13 patients with macrometastases-tumors 1 cm or greater-tumors progressed and serum Tg increased; five have died of thyroid cancer. The disease remained stable in the seven patients with micrometastases. We concluded that in high-risk patients with follicular cell-derived thyroid cancer with high Tg levels and negative diagnostic whole-body scans, only a small number showed meaningful uptake after high doses of RAI. Therefore, widespread use of empiric RAI therapy for such patients who have a large tumor burden should not be encouraged.

Prognostic value of serial serum thyroglobulin determinations after total thyroidectomy for differentiated thyroid cancer

Serial weekly serum samples (for 3 weeks) were obtained from 42 patients with differentiated thyroid cancer (DTC, papillary no.=35, follicular no.=6, Hurthle cell no.=1) for serum thyroid hormone, TSH and TG before and after total thyroidectomy. Serum specimens were also obtained one month after radioiodine (131I) therapy followed by suppressive dose of L-thyroxine (L-T4, 2.5 microg/kg). The patients were subdivided into four groups: group I: the DTC was confined to a single solid nodule (no.=1 2); group II: thyroid malignancy invaded local cervical structures but there were no lymph node metastases (no.=8); group III: DTC with lymph node metastases (no.=6); and group IV: DTC with distant metastases (no.=16). In all group I patients serum TG remained undetectable in spite of elevated serum TSH levels at the 3rd week post-surgery (PS). Only one of group II patients had a detectable serum TG value of 5.2 ng/ml (3rd week PS). By contrast, 37.5% of group III patients had detectable serum TG levels, ranging from 3.4 to 16.8 ng/ml (3rd week PS). Lymph node metastases were detected in 5 of these patients by whole body scan (WBS) and removed surgically in 3. As expected, group IV patients had elevated serum TG values ranging 33.0-958.0 ng/ml and distant metastases were confirmed in all of them by WBS. From the calculations through univariate logistic regression comparing TG concentrations at the 3rd week PS from groups I and II vs groups III and IV, we obtained a cut-off value of 2.3 ng/ml with the following efficacy features: sensitivity=74.5%; specificity=95%; positive predictive value=92.3%; negative predictive value=65.5%; and accuracy=73.8%. After 131I and L-T4 suppressive therapy, only 5 out of 36 patients of groups I, II and III had detectable serum TG levels (3.1-7.0 ng/ml) whereas serum TG was detectable in all group IV patients (ranging 2.5-8.6 ng/ml). We concluded that serum TG concentrations above 2.3 ng/ml at the 3rd week PS could be suggestive of lymph node or distant metastases in patients with DTC. Patients with serum TG above this limit could be considered at risk for metastatic disease and higher doses of diagnostic iodine-131 (131I) may be indicated for actinic ablation.

Detection of prostate-specific membrane antigen expressing cells in blood obtained from renal cancer patients: a potential biomarker of vascular invasion

Originally, prostate-specific membrane antigen (PSMA) was described in benign and malignant prostate cells. On the basis of recent reports that this antigen also is expressed in normal renal proximal tubular cells and in the neovascular endothelium associated with renal carcinoma, we used a nested reverse transcriptase-polymerase chain reaction assay to evaluate whether PSMA-expressing cells might be present in specimens of peripheral blood obtained from renal cancer patients, benign renal tumor patients, and healthy volunteers. Our reverse transcriptase-polymerase chain reaction PSMA assay had a sensitivity of detecting 1 lymph node prostate cancer (LNCaP) per 10(7) lymphocytes. None of the 20 non-renal cancer controls were positive for PSMA mRNA, whereas 11 of 50 patients (22%) with diagnosed renal cancer were positive. Despite a comparative increase of PSMA positivity with stage, no statistical correlation was found. However, 44% of PSMA-positive patients had tumor size greater than 12 cm, versus only 9% in patients negative for PSMA (P = .03), and 67% of positive PSMA patients were found to have vascular invasion versus only 16% of patients negative for PSMA (P = .006; odds ratio, 10.8). This preliminary study suggests the possibility that PSMA expression in peripheral blood might be a useful biomarker for detecting or monitoring the progression of renal cancer in patients.

[Increase in TSH levels in thyroid carcinoma patients after withdrawal of suppressive levothyroxine medication]

AIM

In 76 patients with thyroid carcinoma (60 f., 16 m.; age 51 +/- 15 years; 52 with papillary, 22 with follicular, 2 with Hürthle cell thyroid carcinoma), three different schemes to withdraw LT4 before 131I whole body scintigraphy were compared.

METHOD

In scheme I no interval LT3 medication is applied. Scheme II starts one week after withdrawal of LT4 with a two weeks lasting LT3 medication: 40-80 micrograms LT3/die in the first week and 20 micrograms LT3/die in the second week. Afterwards no further LT3 medication is given. Scheme III is identical to scheme II in the first three weeks but 20 micrograms LT3 medication is continued until 131I-application. Retrospectively 121 studies were evaluated concerning the scheme specific increase of TSH. Factors which may influence the increase of TSH were analysed, i.e. age, sex, thyreoglobuline, LT4 dose, duration of LT4 treatment, histological type of carcinoma, result of 131I whole body scanning.

RESULTS

There was a significant relation between increase of TSH and the applied scheme. Schemes with interval LT3 medication are more comfortable for the patient but time to stimulate TSH to values > or = 30 microIU/ml is prolonged, especially using scheme III. Female patients needed a significantly longer time compared to male patients to reach a TSH value > or = 30 microIE/ml. Concerning repetitive withdrawal of LT4, there was a fair intraindividual reproducibility of the time period from LT4 withdrawal to TSH values > or = 30 microIE/ml.

CONCLUSION

Every scheme has its specific field of indication depending on the compliance of the patients.

Pancreatic pseudocyst resolution after parathyroidectomy for hyperparathyroidism

Hyperparathyroidism is a rare cause of pancreatic inflammatory disease. Appropriate treatment of coexistent hyperparathyroidism and pancreatitis, especially when complicated by pseudocyst formation, is unsettled. We describe two patients with primary hyperparathyroidism who developed pancreatitis associated with multiple pseudocysts. The largest cyst in each patient was 9 and 5 cm, respectively. After correction of hyperparathyroidism and normalization of serum calcium levels by removal of a parathyroid adenoma, the pseudocysts resolved in both patients, as documented with computed tomography. We conclude that uncomplicated pancreatic pseudocysts in patients with primary hyperparathyroidism can be treated expectantly. Surgical correction of hyperparathyroidism and normalization of serum calcium levels should precede pancreatic intervention when possible, since pseudocyst resolution is likely and the risks of postoperative hypercalcemia are avoided.