Active surveillance is a feasible and safe strategy in selected patients with papillary thyroid cancer and suspicious cervical lymph nodes detected after thyroidectomy

Objective

After initial treatment, up to 30% of patients with papillary thyroid cancer (PTC) have incomplete response, mainly cervical lymph node (LN) disease. Previous studies have suggested that active surveillance (AS) is a possible option for these patients. Our aim was to report the results of AS in patients with PTC and cervical LN disease.

Materials and methods

In this retrospective observational study, we included adult patients treated and followed for PTC, who presented with cervical LN disease and were managed with AS. Growth was defined as an increase ≥ 3mm in either diameter.

Results

We included 32 patients: 27 (84.4%) women, age of 39 ± 14 years, all initially treated with total thyroidectomy, and 22 (69%) with therapeutic neck dissection. Cervical LN disease was diagnosed 1 year (0.3-12.6) after initial management, with a diameter of 9.0 mm (6.0-19.0). After a median AS of 4.3 years (0.6-14.1), 4 (12.5%) patients had LNgrowth: 2 (50%) of whom were surgically removed, 1 (25%) was effectively treated with radiotherapy, and 1 (25%) had a scheduled surgery. Tg increase was the only predictive factor of LN growth evaluated as both the delta Tg (p < 0.0366) and percentage of Tg change (p < 0.0140). None of the included patients died, had local complications due to LN growth or salvage therapy, or developed distant metastases during follow-up.

Conclusion

In selected patients with PTC and suspicious cervical LNs diagnosed after initial treatment, AS is a feasible and safe strategy as it allows effective identification and treatment of the minority of patients who progress.

ThyroidPrint®: clinical utility for indeterminate thyroid cytology

Molecular testing contributes to improving the diagnosis of indeterminate thyroid nodules (ITNs). ThyroidPrint® is a ten-gene classifier aimed to rule out malignancy in ITN. Post-validation studies are necessary to determine the real-world clinical benefit of ThyroidPrint® in patients with ITN. A single-center, prospective, noninterventional clinical utility study was performed, analyzing the impact of ThyroidPrint® in the physicians' clinical decisions for ITN. Demographics, nodule characteristics, benign call rates (BCRs), and surgical outcomes were measured. Histopathological data were collected from surgical biopsies of resected nodules. Of 1272 fine-needle aspirations, 109 (8.6%) were Bethesda III and 135 (10.6%) were Bethesda IV. Molecular testing was performed in 155 of 244 ITN (63.5%), of which 104 were classified as benign (BCR of 67.1%). After a median follow-up of 15 months, 103 of 104 (99.0%) patients with a benign ThyroidPrint® remained under surveillance and one patient underwent surgery which was a follicular adenoma. Surgery was performed in all 51 patients with a suspicious for malignancy as per ThyroidPrint® result and in 56 patients who did not undergo testing, with a rate of malignancy of 70.6% and 32.1%, respectively. A higher BCR was observed in follicular lesion of undetermined significance (87%) compared to atypia of undetermined significance (58%) (P < 0.05). False-positive cases included four benign follicular nodules and six follicular and four oncocytic adenomas. Our results show that, physicians chose active surveillance instead of diagnostic surgery in all patients with a benign ThyroidPrint® result, reducing the need for diagnostic surgery in 67% of patients with preoperative diagnosis of ITN.

[An update on parathyroid carcinoma]

Parathyroid carcinoma is a rare malignant disease that presents as a sporadic or familial primary hyperparathyroidism (PHP). The latter is associated with some genetic syndromes. It occurs with equal frequency in both sexes, unlike PHP caused by parathyroid adenoma that is more common in women. It should be suspected in cases of severe hypercalcemia, with high parathyroid hormone levels and a palpable cervical mass. Given the difficulty in distinguishing between parathyroid carcinoma and adenoma prior to the surgery, the diagnosis is often made after parathyroidectomy. The only curative treatment is complete surgical resection with oncologic block resection of the primary tumor to ensure free margins. Adjuvant therapies with chemotherapy or radiation therapy do not modify overall or disease-free survival. Recurrences are common and re-operation of resectable recurrent disease is recommended. The palliative treatment of symptomatic hypercalcemia is crucial in persistent or recurrent disease after surgery since morbidity and mortality are more associated with hypercalcemia than with tumor burden.

Polyostotic fibrous dysplasia (McCune-Albright) with rare multiple epiphyseal lesions in association with aneurysmal bone cyst and pathologic fracture

Fibrous dysplasia, including McCune-Albright syndrome, is a genetic, non-inheritable benign bone disorder that may involve a single or multiple bone, typically occurring in the diaphysis or the metaphysis of long bones. In very rare instances polyostotic fibrous dysplasia present involvement of the epiphysis in long bones. Aneurysmal bone cysts are benign, expansile, lytic bone lesions formed by cystic cavities containing blood, that may occur de novo or secondary to other lesions of bone, including fibrous dysplasia. We report a case of an 18-year-old female with polyostotic fibrous dysplasia (McCune-Albright syndrome) with diaphyseal and unusual multiple foci of epiphyseal involvement of long bones as well as in the patella, and a simultaneous aneurysmal bone cyst of the left femoral neck with pathologic fracture. This is the first report of a simultaneous aneurysmal bone cyst in a patient with polyostotic fibrous dysplasia (McCune-Albright syndrome) with involvement of diaphysis and epiphysis of long bones, highlighting that fibrous dysplasia should be included in the differential diagnosis of polyostotic tumors involving the diaphysis as well as the epiphysis. In patients with polyostotic fibrous dysplasia there should be an active search for lesions in the epiphysis.

Warthin-like and classic papillary thyroid cancer have similar clinical presentation and prognosis

Objective

Warthin-like papillary thyroid cancer (WL-PTC) is an uncommon variant of PTC, usually associated with lymphocytic thyroiditis. Scarce evidence suggests that WL-PTC has similar clinical presentation to classic PTC (C-PTC), with no studies comparing risks of recurrence and response to treatment between both variants. Our objective was to describe the clinical presentation and prognosis of WL-PTC and compare it to C-PTC.

Methods

Retrospective analysis of a prospective cohort, including 370 (96%) patients with C-PTC and 17 (4%) with WL-PTC, consecutively treated with total thyroidectomy with or without RAI, followed for at least 6 months. We compared clinical presentation, risk of mortality and recurrence, as well as response to treatment between both variants.

Results

Of the total cohort: 317 (82%) female, 38 ± 13.5 years, median follow-up 4 years (0.5-28.5); most of them stage I and low/intermediate risk of recurrence. We found no differences regarding clinical-pathological data and risk of recurrence. WL-PTC was associated with a higher rate of anti-thyroglobulin antibodies (TgAb) (65% vs. 36%, p = 0.016) and lymphocytic thyroiditis (59% vs. 34%, p = 0.03). The rates of biochemical and structural incomplete responses were similar in both variants. WL-PTC had a lower rate of excellent response (23% vs. 54%, p = 0.01), which became non-significant when performing analysis by TgAb presence (50% vs. 67%, p = NS).

Conclusion

WL-CPT and C-CPT have similar clinical presentation and rate of recurrence. The lower rate of excellent response to treatment in WL-PTC is due to a higher frequency of TgAb. WL-PCT should not be considered an aggressive variant of PTC.

A Thyroid Genetic Classifier Correctly Predicts Benign Nodules with Indeterminate Cytology: Two Independent, Multicenter, Prospective Validation Trials

Background: Although most thyroid nodules with indeterminate cytology are benign, in most of the world, surgery remains as the most frequent diagnostic approach. We have previously reported a 10-gene thyroid genetic classifier, which accurately predicts benign thyroid nodules. The assay is a prototype diagnostic kit suitable for reference laboratory testing and could potentially avoid unnecessary diagnostic surgery in patients with indeterminate thyroid cytology. Methods: Classifier performance was tested in two independent, ethnically diverse, prospective multicenter trials (TGCT-1/Chile and TGCT-2/USA). A total of 4061 fine-needle aspirations were collected from 15 institutions, of which 897 (22%) were called indeterminate. The clinical site was blind to the classifier score and the clinical laboratory blind to the pathology report. A matched surgical pathology and valid classifier score was available for 270 samples. Results: Cohorts showed significant differences, including (i) clinical site patient source (academic, 43% and 97% for TGCT-1 and -2, respectively); (ii) ethnic diversity, with a greater proportion of the Hispanic population (40% vs. 3%) for TGCT-1 and a greater proportion of African American (11% vs. 0%) and Asian (10% vs. 1%) populations for TGCT-2; and (iii) tumor size (mean of 1.7 and 2.5 cm for TGCT-1 and -2, respectively). Overall, there were no differences in the histopathological profile between cohorts. Forty-one of 155 and 45 of 115 nodules were malignant (cancer prevalence of 26% and 39% for TGCT-1 and -2, respectively). The classifier predicted 37 of 41 and 41 of 45 malignant nodules, yielding a sensitivity of 90% [95% confidence interval; CI 77-97] and 91% [95% CI 79-98] for TGCT-1 and -2, respectively. One hundred one of 114 and 61 of 70 nodules were correctly predicted as benign, yielding a specificity of 89% [95% CI 82-94] and 87% [95% CI 77-94], respectively. The negative predictive values for TGCT-1 and TGCT-2 were 96% and 94%, respectively, whereas the positive predictive values were 74% and 82%, respectively. The overall accuracy for both cohorts was 89%. Conclusions: Clinical validation of the classifier demonstrates equivalent performance in two independent and ethnically diverse cohorts, accurately predicting benign thyroid nodules that can undergo surveillance as an alternative to diagnostic surgery.

Differential expression profile of CXCR3 splicing variants is associated with thyroid neoplasia. Potential role in papillary thyroid carcinoma oncogenesis?

Papillary thyroid cancer (PTC) is the most prevalent endocrine neoplasia. The increased incidence of PTC in patients with thyroiditis and the frequent immune infiltrate found in PTC suggest that inflammation might be a risk factor for PTC development. The CXCR3-ligand system is involved in thyroid inflammation and CXCR3 has been found upregulated in many tumors, suggesting its pro-tumorigenic role under the inflammatory microenvironment. CXCR3 ligands (CXCL4, CXCL9, CXCL10 and CXCL11) trigger antagonistic responses partly due to the presence of two splice variants, CXCR3A and CXCR3B. Whereas CXCR3A promotes cell proliferation, CXCR3B induces apoptosis. However, the relation between CXCR3 variant expression with chronic inflammation and PTC development remains unknown. Here, we characterized the expression pattern of CXCR3 variants and their ligands in benign tumors and PTC. We found that CXCR3A and CXCL10 mRNA levels were increased in non-metastatic PTC when compared to non-neoplastic tissue. This increment was also observed in a PTC epithelial cell line (TPC-1). Although elevated protein levels of both isoforms were detected in benign and malignant tumors, the CXCR3A expression remained greater than CXCR3B and promoted proliferation in Nthy-ori-3-1 cells. In non-metastatic PTC, inflammation was conditioning for the CXCR3 ligands increased availability. Consistently, CXCL10 was strongly induced by interferon gamma in normal and tumor thyrocytes.

Our results suggest that persistent inflammation upregulates CXCL10 expression favoring tumor development via enhanced CXCR3A-CXCL10 signaling. These findings may help to further understand the contribution of inflammation as a risk factor in PTC development and set the basis for potential therapeutic studies.

Effect of Propionibacterium acnes (PA) injection on intervertebral disc degeneration in a rat model: Does it mimic modic changes?

INTRODUCTION

Multiple reports of bacterial isolates in human disc tissue have suggested a role of low-grade infection on intervertebral disc degeneration and modic changes (MC) generation. Animal models have been extensively used to study IDD; however, until recently, no consideration had been given to eventual infectious processes. To reproduce the phenomena by inoculating an infecting agent would support the infectious hypothesis. Therefore, we studied the effect of Propionibacterium acnes (PA) inoculation on rat-tails and determined whether it would produce MCs on the adjacent endplates.

HYPOTHESIS

Disc infection with PA would accelerate IDD compared with the standard model and would also lead to MCs on the adjacent endplates.

METHODS

Twelve Sprague-Dawley rats were randomized to receive a needle puncture in a caudal tail disc with either saline (control) or an inoculum of 5×10⁷ CFU of strain 1a PA. Twelve weeks later, the rats were euthanized and the tails were analyzed. The main assessment criteria were obtained from the post-mortem MRI: T2 values of punctured discs and adjacent endplates, as well as disc volumes. A histological grading score for IDD was also used, measuring the morphology and cellularity of the nucleus and annulus, as well as endplate disruption.

RESULTS

The median T2 value and disc volume were smaller in PA-punctured discs [T2 value: 30ms (23-44) vs. 61ms (38-132), respectively, P=0.01; 0.01mm³ (0.01-0.05) vs. 0.5mm³ (0.01-5.35), respectively; P=0.049]. There was no change in the adjacent endplates. There was no significant difference in histological grading between the test and control [13 (10-14) vs. 10.5 (6-13); P=0.05].

DISCUSSION

Inoculation of caudal discs with PA generated increased degeneration; however, no MCs were observed on the adjacent endplates. A better understanding of low-grade disc infections is still needed.

LEVEL OF EVIDENCE

V (animal study).

A 10-Gene Classifier for Indeterminate Thyroid Nodules: Development and Multicenter Accuracy Study

BACKGROUND

In most of the world, diagnostic surgery remains the most frequent approach for indeterminate thyroid cytology. Although several molecular tests are available for testing in centralized commercial laboratories in the United States, there are no available kits for local laboratory testing. The aim of this study was to develop a prototype in vitro diagnostic (IVD) gene classifier for the further characterization of nodules with an indeterminate thyroid cytology.

METHODS

In a first stage, the expression of 18 genes was determined by quantitative polymerase chain reaction (qPCR) in a broad histopathological spectrum of 114 fresh-tissue biopsies. Expression data were used to train several classifiers by supervised machine learning approaches. Classifiers were tested in an independent set of 139 samples. In a second stage, the best classifier was chosen as a model to develop a multiplexed-qPCR IVD prototype assay, which was tested in a prospective multicenter cohort of fine-needle aspiration biopsies.

RESULTS

In tissue biopsies, the best classifier, using only 10 genes, reached an optimal and consistent performance in the ninefold cross-validated testing set (sensitivity 93% and specificity 81%). In the multicenter cohort of fine-needle aspiration biopsy samples, the 10-gene signature, built into a multiplexed-qPCR IVD prototype, showed an area under the curve of 0.97, a positive predictive value of 78%, and a negative predictive value of 98%. By Bayes' theorem, the IVD prototype is expected to achieve a positive predictive value of 64-82% and a negative predictive value of 97-99% in patients with a cancer prevalence range of 20-40%.

CONCLUSIONS

A new multiplexed-qPCR IVD prototype is reported that accurately classifies thyroid nodules and may provide a future solution suitable for local reference laboratory testing.

Desmoplastic Fibroma of the Mandible in a Pediatric Patient: A Case Report of Resection and Reconstruction With A Six-Year Follow-Up

Desmoplastic fibroma (DF) of bone is considered a benign but locally aggressive tumor of fibroblastic origin. DF is rare, representing less than 1% of all bone tumors. Approximately 84% of patients are younger than 30 years. DF has a slow but aggressive growth potential and can recur locally when it has not been completely excised. Complete resection is the treatment of choice to decrease recurrence and morbidity. Mandibular reconstruction is mandatory in pediatric patients to ensure correct craniofacial development. The present report describes the case of a pediatric patient with mandibular DF in whom complete resection and immediate reconstruction with a fibula flap proved a satisfactory treatment option, with low morbidity and excellent esthetic and functional results at 6-year follow-up.

[Diagnostic yield of fine-needle aspiration cytology for the detection of thyroid cancer in pediatric patients]

BACKGROUND

Despite the low frequency of thyroid nodules (TN) in children, one of every four is malignant. Fine-needle aspiration cytology (FNAC) has a high accuracy detecting thyroid cancer.

AIM

To evaluate the performance of FNAC in TN in Chilean children to detect thyroid cancer.

PATIENTS AND METHODS

The pathological reports of 77 thyroidectomies and 103 FNAC carried out in patients aged less than 18 years, between 2002 and 2013 were reviewed. In 36 patients aged 15 ± 2 years (77% women), both the reports of the thyroidectomy and FNAC were available. The cytological specimens were reclassified based on Bethesda 2010. The histology was classified as benign (nodular hyperplasia and follicular adenoma, n = 18), or malignant (papillary, follicular and medullar carcinoma, n = 18). The concordance of the cytology with the final biopsy report was calculated.

RESULTS

FNAC classified 13 specimens as definitively benign and 13 as definitively malignant. Among these, these concordances with the pathological study of the biopsy was 100%. Of six cytology tests considered "suspicious for follicular neoplasm" by FNAC, four were benign (67%), and two malignant (33%). Of four cytology tests considered "suggestive of carcinoma" by FNAC, one was benign (25%), and three malignant (75%).

CONCLUSIONS

Among the studied children, there was a good concordance between FNAC and surgical biopsies. Therefore a FNAC should be carried out when malignancy is suspected in pediatric patients with a TN.

[From macro to micro thyroid carcinoma: records of a clinical hospital from 1991 to 2010]

BACKGROUND

The prevalence of thyroid cancer has increased, particularly in nodules smaller than 10 mm, probably due to the growing use of routine thyroid ultrasound. There is controversy about the biological behavior of micro carcinomas and the relevance of their early detection.

AIM

To characterize the clinical presentation of thyroid cancer over 20 years in an University medical center and to evaluate the differences between macro and micro carcinomas.

PATIENTS AND METHODS

We reviewed 1547 surgical biopsy records of thyroid cancer in our institution obtained between 1991 and 2010.

RESULTS

We observed a sustained increase in the rate of thyroidectomies for thyroid cancer (per 1000 surgical procedures) in the study period. Papillary, follicular, mixed, medullary and anaplastic carcinomas were observed in 95, 3, 2, 0.5 and 0.1% of biopsies, respectively. The incidence of tumors of less than 10 mm (micro carcinoma) also increased. Those findings were associated with a significant decrease in tumor aggressiveness, determined by a low frequency of surgical margin involvement of thyroid capsule, perithyroid tissue invasion, vascular permeation and lymph node metastases.

CONCLUSIONS

The increased prevalence of thyroid cancer, especially of micro carcinomas, may reflect the greater use of diagnostic ultrasound or represent a real change in the biological behavior of this disease and our data suggest that further studies are needed to know the impact of early treatment in the outcome of those patients because of the real less histologic agressiveness of micro carcinomas.

Pseudotumor of the mandible as first presentation of hemophilia in a 2-year-old male: a case report and review of jaw pseudotumors of hemophilia

Pseudotumor of hemophilia (PTH) is a rare complication seen in approximately 1-2% of cases of hemophilia. Although much more common in long bones, the pelvis, and small bones of the hands and feet than in the jaws, occasionally hemorrhage in the jaws occurs with this result. We present a case in a two-year-old male with a one-month swelling of the right mandible without significant medical history or diagnosis of hemophilia who was subsequently diagnosed as having Factor IX deficiency, or hemophilia B. A review of the literature revealed only 15 reported cases of PTH of the jaws and salient features of PTH in the jaws are discussed. The differential diagnosis of masses occurring in the jaws of children is limited and PTH should be considered when a mass presents with rapid growth and the histopathologic features are not diagnostic for a neoplastic process, even in the absence of a prior diagnosis of hemophilia as PTH may be the initial manifestation of this disease.

An ultrasound model to discriminate the risk of thyroid carcinoma

RATIONALE AND OBJECTIVES

Thyroid nodules are common on ultrasonographic examination and are mostly benign. Ultrasound characteristics may help discriminate thyroid carcinoma (TC) from benign nodules. The aims of this study were to identify ultrasonographic characteristics associated with TC and to validate a previously proposed model based on the presence of three ultrasonographic characteristics.

MATERIALS AND METHODS

From a protocolized prospective registry of 1108 fine needle aspiration biopsies performed during a 16-month period at an ambulatory center, the ultrasonographic characteristics of TC and non-TC biopsies were compared. Adjusted odds ratios (ORs) and likelihood ratios for TC were estimated for eight combinations of three previously identified characteristics (microcalcifications, hypoechogenicity, and irregular borders).

RESULTS

Microcalcifications (OR, 6.6; 95% confidence interval [CI], 4.4-9.9), hypoechogenicity (OR, 4.7; 95% CI, 2.8-8.0), and irregular borders (OR, 4.3; 95% CI, 2.8-6.5) were independently associated with TC. When added to a logistic regression model, the three ultrasonographic characteristics remained statistically significant. In the absence of these three features, the likelihood ratio for TC was 0.1 (95% CI, 0.0-0.2), while in their simultaneous presence, the likelihood ratio was 11 (95% CI, 6.6-19.0).

CONCLUSIONS

The absence or simultaneous presence of three simple ultrasonographic characteristics generates a large change of pretest probability of TC and could avoid unnecessary fine needle aspiration biopsy.

[An ultrasound score to predict the presence of papillary thyroid carcinoma. Preliminary report]

BACKGROUND

Thyroid nodules are common and associated to a low risk of malignancy. Their clinical assessment usually includes a fine needle aspiration biopsy (FNAB).

AIM

To identify ultrasonographic characteristics associated to papillary thyroid carcinoma (PTC) and generate a score that predicts the risk of PTC.

MATERIAL AND METHODS

Retrospective review of all fine needle aspiration biopsies of the thyroid performed in a lapse of two years. Biopsies that were conclusive for PTC were selected and compared with an equal amount of randomly selected biopsies that disclosed a benign diagnosis.

RESULTS

One hundred twenty two biopsies of a total of 1,498 were conclusive for PTC. Univariate analysis showed associations with PTC for the presence of micro-calcifications (Odds ratio (OR) 49.2: 95% confidence intervals (CI) 18.7-140.9), solid predominance (OR 25.1; 95% CI 6-220), hypoechogenicity (OR 23.5, 95% CI 6.5-122.6), irregular borders (OR 17, 95% CI 7.2-42.9), lymph node involvement (OR 12.3, 95% CI2.7-112), central vascularization (OR 12.2, 95% CI 4.8-33.3), local invasion and hyperechogenicity (OR 0.2; CI 95% CI 0.03-0.6). Multivariate analysis disclosed microcalcifications (OR 28.1; CI 95% 8.9-89), hypoechogenicity (OR 9.4; 95% CI 1.5-59.5) and irregular borders (OR 4.7; CI 95% 1.5-15) as the variables independently associated with the presence of PTC. The prevalence of PTC in the presence of the three variables was 97.6% (Likelihood ratio (LR) 45) and 5.4% in their absence (LR 0.06).

CONCLUSIONS

This scale predicts the presence or absence of PTC using simple ultrasound characteristics.

Three novel mutations in the CFTR gene identified in Galician patients

We report three novel CFTR missense mutations detected in Spanish patients from Galicia (North West of Spain). In the first case, a patient homozygous for a novel S1045Y mutation died due to pulmonary problems. In the other two cases, both heterozygous for novel mutations combined with the F508del mutation, clinical symptoms were different depending on the mutation, detected as M595I and A107V.

Arteriovenous malformation of the pancreas: report of a case

Arteriovenous malformation (AVM) of the pancreas (AVMP) is uncommon and generally asymptomatic; therefore, few cases have so far been reported. The symptoms of AVMP include gastrointestinal bleeding, pain, and portal hypertension. Definitive diagnosis is confirmed by angiographic study, and surgery is the only effective treatment. We report a case of AVMP confirmed by computed tomography, magnetic resonance imaging, and angiographic study of the abdomen, in a patient who presented to us with epigastric pain. He underwent a pancreaticoduodenectomy, following which his symptoms resolved.

[Recurrence of differentiated thyroid carcinoma without concomitant elevation of serum thyroglobulin: report of two cases]

Thyroid carcinoma is the most prevalent endocrine tumor, and the papillary carcinoma (PC) is the most common histological type. In the follow-up, after thyroidectomy serum thyroglobulin (s-Tg) is used as a marker to evaluate recurrence of thyroid carcinoma. In most cases, this parameter allows an adequate diagnosis, but occasionally s-Tg may miss the detection of a recurrence. We report a 57 year-old female and a 36 year-old male subjected to a total thyroidectomy for a papillary thyroid carcinoma with intermediate and high-risk of recurrence. Both had a cervical recurrence without a concomitant increase in s-Tg levels. In both, Tg staining was positive in the tumor cells. These cases confirm that in these patients, the follow-up must be done with measurement of s-Tg and complementary diagnostic tests.

Carcinoma familiar del tiroides no medular (CFTNM): características de presentación en 17 casos

BACKGROUND

Papillary thyroid carcinoma can have familial aggregation.

AIM

To compare retrospectively familial non medullary thyroid carcinoma (FNMTC) with sporadic papillary thyroid carcinoma (PTC).

MATERIAL AND METHODS

Retrospective analysis of medical records of patients with thyroid carcinoma. An index case was defined as a subject with the diagnosis of differentiated thyroid carcinoma with one or more first degree relatives with the same type of cancer. Seventeen such patients were identified and were compared with 352 subjects with PTC.

RESULTS

The most common affected relatives were sisters. Patients with FNMTC were younger than those with PTC. No differences were observed in gender, single or multiple foci, thyroid capsule involvement, surgical border involvement, number of affected lymph nodes and coexistence of follicular hyperplasia. Patients with FNMTC had smaller tumors and had a nine times more common association with lymphocytic thyroiditis. Five patients with FNMTC had local recurrence during 4.8 years of follow up.

CONCLUSIONS

Patients with FNMTC commonly have an associated chronic thyroiditis, are younger and have smaller tumors than patients with PTC.

New splicing mutation of MEN1 gene affecting the translocation of menin to the nucleus

Multiple endocrine neoplasia type 1 (MEN1) is a syndrome inherited in an autosomal dominant trait caused by the inactivation of the tumor suppressor gene MEN1.

OBJECTIVE

To communicate a family with a new heterozygous germ line mutation in the intronic region of MEN1 gene and to study its influence in the menin expression.

PATIENTS AND METHODS

We studied 5 members of a family with symptomatic hyperparathyroidism (HPT). One of them had also a neuroendocrine pancreatic tumor, and 2 had non-functional multinodular cortical adrenal hyperplasia compatible with the diagnosis of MEN1. After the mutation was identified, HSP92II restriction enzyme was used to determine both zygosity and segregation of the mutation. RT-PCR from leukocyte's isolated mRNA and western blot from pancreatic tumor tissue were performed. In vitro studies were done in Chinese hamster ovary (CHO) cells transfected with reporter minigenes carrying the coding regions spanning exon (EX)-intron 9 and EX10 with the mutant and the wild type sequences.

RESULTS

We identified a heterozygous G-to-T substitution in the intron-EX junction (IVS9-1 G>T) of MEN1 gene in the index case and the family members. The mRNA from patient's leukocytes was larger (934 bp) in comparison to the normal transcript (717 bp). Immunoblot analysis demonstrated that wild type (67 kDa) and two additional mutant proteins (approximately 55 and approximately 90 kDa) were expressed in the pancreatic tissue. The in vitro study showed a 45% nuclear localization of the mutated menin signal and a 95% in the wild type protein.

CONCLUSIONS

We identified a new intronic heterozygous germ line mutation (IVS9-1G>T) of MEN1 gene in a family affected by MEN1 syndrome. This mutation alters the splice acceptor site of intron 9 that promotes an incorrect splicing, generating aberrant proteins without the nuclear localization signals necessary for the normal menin translocation to the nucleus.

[Pathological characteristics of thyroid microcarcinoma. A review of 402 biopsies]

BACKGROUND

Thyroid microcarcinoma is a tumor of 10 mm or less, that should have a low risk of mortality. However, a subgroup of these carcinomas is as aggressive as bigger tumors.

AIM

To describe the pathological presentation of these tumors, and compare them with larger tumors.

MATERIAL AND METHODS

All pathological samples of thyroid carcinoma that were obtained between 1992 and 2003, were studied. In all biopsies, the pathological type, tumor size, the focal or multifocal character, the presence of lymph node involvement and the presence of lymphocytic thyroiditis or thyroid hyperplasia, were recorded.

RESULTS

One hundred eighteen microcarcinomas and 284 larger tumors were studied. The mean age of patients with microcarcinoma and larger tumors was 42.7+/-14 and 49.3+/-16 years respectively (p <0,001) and 83% were female, without gender differences between tumor types. Mean size of microcarcinomas was 8.6 mm and 116 (98%) were papillary carcinomas. Of these, 109 (94%) were well differentiated and seven (6%) were moderately differentiated. Thirty six (31%) were multifocal and in 10 (8,6%), there was lymph node involvement. The mean size of larger tumors was 23.8 mm and 241 (85%) were papillary carcinomas. Of these, 200 (83%) were well differentiated, and 41 (17%) were moderately differentiated. Eighty five (35%) were multifocal and in 44 (18%) there was lymph node involvement. The prevalence of thyroiditis and hyperplasia was significantly higher among microcarcinomas than in larger tumors (15 and 2.5%, respectively, p <0.001, for the former; 32.4 and 1.7%, respectively, p <0.001, for the latter).

CONCLUSIONS

In this series, one third of microcarcinomas were multifocal and 10% had lymph node involvement. Therefore, the aggressiveness of these tumors is higher than what is reported in the literature and they should be treated with total thyroidectomy.

Comparative Analysis of Loss of Heterozygosity and Microsatellite Instability in Adult and Pediatric Melanoma

Although 0.3% of melanomas occur in children, the incidence has risen in past decades. In adult melanoma, some chromosomal regions in 1p, 6q, 9p, 10q, and 11q are frequently deleted. Microsatellite instability (MSI), which reflects impaired DNA repair, has been found at low levels in adult melanoma and melanocytic nevi. To investigate the molecular changes in pediatric melanoma, a screening for loss of heterozygosity and microsatellite instability was performed and compared with changes found in adult melanoma. Formalin-fixed, paraffin-embedded tissues from 10 adult melanomas, 9 melanocytic nevi, and 8 pediatric melanomas were microdissected and the DNA was extracted. Loss of heterozygosity and microsatellite instability were evaluated using 13 microsatellite repeat polymorphisms located in 1p36, 1q32, 2p12, 2p22-25, 2q33-37, 9p21, 10q23.3, 11q23, 13q14, 17p13, and 17q21. The overall frequency of loss of heterozygosity was 0.09 for nevi, 0.30 for adult melanoma, and 0.43 for pediatric melanoma (nevi vs. adult melanoma, P = 0.0082; nevi vs. pediatric melanoma, P = 0.0092). Pediatric melanoma has more loss of heterozygosity (44%) in 11q23 than adult melanoma (7%, P = 0.046). The microsatellite instability overall frequency was greater in pediatric melanoma (0.24) than nevi (0.05, P = 0.0031) and adult melanoma (0.09, P = 0.0195). Our findings suggest that pediatric melanoma has a different abnormal pattern than adult melanoma. Pediatric melanoma has more microsatellite instability than adult melanoma. 11q23 could contain genes related to the early age onset of melanoma. The high frequency of microsatellite instability is coincidental with the finding of higher levels of microsatellite instability in pediatric brain tumors and could play a role in the pathogenesis of pediatric melanoma.

Gastric cancer after Roux-en-Y gastric bypass

Roux-en-Y gastric bypass (RYGBP) is one of the most commonly performed surgical procedures for morbid obesity. Several complications that may develop in the short- and long-term have been reported. We present a patient who presented with cancer in the bypassed stomach 8 years after RYGBP. Although the development of this lesion is rare and only a few cases have been reported, there are aspects worthy of discussion. Several monitoring, diagnostic and therapeutic alternatives are analyzed.

[Thyroid microcarcinoma with an aggressive evolution. Report of one case]

The treatment of papillary thyroid carcinoma of less than 10 mm diameter is a matter of controversy. The incidental finding of papillary microcarcinomas in autopsies is frequent and some authors postulate that these tumors are biologically inactive and should only be observed. We report a 21 years old woman with a papillary thyroid cancer of 6 x 5 x 5 mm and bilateral paratracheal metastases, that was subjected to a total thyroidectomy. She received 200 mCi of radioiodine. Two years after surgery, a new nodule of 9.6 mm diameter was detected by ultrasound, that was treated with a new dose of 200 mCi of radioiodine. One year later a suprasternal mass of 2 cm diameter and 3 enlarged lymph nodes were detected. She was subjected to a surgical lymph node dissection of the neck and the biopsy confirmed the presence of cancer. She received a new dose of 300 mCi of radioiodine. The mother of the patient had a 7 mm thyroid nodule that was also a papillary carcinoma.

Bile secretory function in the obese Zucker rat: evidence of cholestasis and altered canalicular transport function

BACKGROUND

Obese Zucker rats (ZR) have been used as an experimental model for non-alcoholic fatty liver disease and are particularly susceptible to various types of liver injury. Bile secretory function has not been assessed in ZR.

AIM

To study bile secretion and expression of the main hepatobiliary transporters in ZR.

METHODS

Bile flow and biliary secretion of lipids and glutathione were determined in eight and 14 week old obese ZR and their lean controls. Protein mass and mRNA of the Na(+)/taurocholate cotransporting polypeptide (Ntcp), the bile salt export pump (Bsep), and the multidrug resistant associated protein 2 (Mrp2) were assessed by western and northern blot, respectively. The effects of administration of a tumour necrosis factor alpha inactivator (etanercept) and an insulin sensitiser (rosiglitazone) were assessed in obese ZR while leptin was given to non-obese rats to study its effect on Mrp2 expression.

RESULTS

ZR exhibited increased body weight and hyperlipidaemia. Only 14 week old obese ZR has fatty liver. Decreased bile flow and biliary lipid and glutathione secretion as well as reduced hepatic transport of both taurocholate and bromosulphthalein were found in obese ZR. Hepatic Mrp2 protein mass was markedly reduced (-70%) in obese rats while Ntcp and Bsep protein levels were similar to lean rats. Downregulation of Mrp2 seems to involve both transcriptional and post-transcriptional mechanisms probably related to insulin and leptin resistance.

CONCLUSIONS

Obese ZR exhibit an impaired bile secretory function with significant functional and molecular alterations consistent with mild cholestasis. A defective hepatobiliary transport capacity may be a contributory factor in rendering the obese ZR more susceptible to liver injury.

Congenital lipoid adrenal hyperplasia caused by a novel splicing mutation in the gene for the steroidogenic acute regulatory protein

Steroidogenic acute regulatory protein (StAR) plays a crucial role in the transport of cholesterol from the cytoplasm to the inner mitochondrial membrane, facilitating its conversion to pregnenolone by cytochrome P450scc. Its essential role in steroidogenesis was demonstrated after observing that StAR gene mutations gave rise to a potentially lethal disease named congenital lipoid adrenal hyperplasia, in which virtually no steroids are produced. We report here a 2-month-old female patient, karyotype 46XY, who presented with growth failure, convulsions, dehydration, hypoglycemia, hyponatremia, hypotension, and severe hyperpigmentation suggestive of adrenal insufficiency. Serum cortisol, 17OH-progesterone, dehydroepiandrosterone sulfate, testosterone, 17OH-pregnenolone, and aldosterone levels were undetectable in the presence of high ACTH and plasma renin activity levels. Immunohistochemical analysis of testis tissues revealed the absence of StAR protein. Molecular analysis of StAR gene demonstrated a homozygous G to T mutation within the splice donor site of exon 1 (IVS1 + 1G>T). Her parents and one brother were heterozygous for this mutation. In vitro analysis of the mutation was performed in COS cells transfected with minigenes coding regions spanning exon-intron 1 to 3 carrying the mutant and the wild-type sequences. RT-PCR analyses of the mutant gene showed an abnormal mRNA transcript of 2430 bp (normal size 433 bp). Sequence analysis of the mutant mRNA demonstrated the retention of intron 1. Immunolocalization of the StAR minigene product detected the peptide in the mitochondria of COS cells transfected with the wild-type minigene but not in those transfected with the mutant minigene. We conclude that this mutation gives rise to a truncated StAR protein, which lacks an important N-terminal region and the entire lipid transfer domain.