Application of three-dimensional imaging software to map carcinomatosis in recurrent ovarian cancer.

The treatment of recurrent ovarian cancer has been based on systemic therapy. The role of secondary cytoreductive surgery has been addressed recently in several trials. Imaging plays a key role in helping the surgical team to decide which patients will have resectable disease and benefit from surgery. The role of staging laparoscopy and several imaging and clinical scores has been extensively debated in the field. In other surgical fields there have been reports of using 3D imaging software and 3D printed models to help surgeons better plan the surgical approach. To the best of our knowledge, we report the first case of a patient with recurrent ovarian cancer undergoing 3D modeling before secondary cytoreductive surgery. The 3D modeling was of most value to evaluate the extension of the disease in our patient who underwent a successful secondary cytoreductive surgery and is currently free of the disease.

A Case of Amyloid Goitre in Heavy Chain Amyloidosis: Diagnostic Challenges and Clinical Implications.

Immunoglobulin heavy chain amyloidosis (AH amyloidosis) is an extremely rare subtype of immunoglobulin-derived amyloidosis and there is limited literature on how to diagnose and manage this disorder. We describe a rare case of AH amyloidosis with amyloid goitre and the importance of mass spectrometry in the identification of the different types of amyloids. While additional studies are needed, several observations suggest important practical implications, including differences in clinical picture, prognosis, and pathologic diagnosis. LEARNING POINTS: Immunoglobulin heavy chain amyloidosis is an extremely rare subtype of immunoglobulin-derived amyloidosis and amyloid goitre is even rarer.There is limited literature on how to diagnose and manage this disorder.This case portrays one of these cases - one of the few existing in the literature - and reinforces the diagnostic complexity of this entity.

Prognosis of polymerase epsilon (POLE) mutation in high-grade endometrioid endometrial cancer: Systematic review and meta-analysis.

BACKGROUND: POLE mutated endometrial carcinomas may represent a subspecific type of tumors harboring a more favorable prognosis. Grade 3 (G3 or high-grade) endometrioid endometrial carcinomas remain a clinical dilemma, with some tumors behaving as the low-grade counterparts and others presenting a more aggressive behavior. OBJECTIVES: To determine the association between POLE mutational status and the overall-survival (OS) and progression-free-survival (PFS) of patients with G3 endometrioid endometrial cancer (EC). We also aimed to determine the prevalence of POLE mutations in G3 endometrioid EC. METHODS: We conducted a systematic review in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines (PROSPERO No: CRD4202340008). We searched the following electronic databases: PubMed/Medline, EMBASE, Cochrane Library, Scopus, and Web of Science. For time-to-event data, the effect of POLE mutation in G3 EC was described using hazard ratios (HRs) and corresponding 95% confidence intervals (CIs). Individual patient data for each study was investigated if available from the study authors. If individual patient data were not available, information regarding time-to-event outcomes was extracted using an appropriate methodology. OS and PFS were analyzed using both one-stage and two-stage approaches, the Kaplan-Meier method, and Cox-proportional hazards models. RESULTS: This systematic review and meta-analysis included 19 studies with 3092 patients who had high-grade endometrioid EC. Patients with POLE mutations had lower risks of death (HR = 0.36, 95% CI 0.26 to 0.50, I2 = 0%, 10 trials) and disease progression (HR = 0.31, 95% CI 0.17 to 0.57, I2 = 33%, 10 trials). The pooled prevalence of POLE mutation was 11% (95% CI 9 to 13, I2 = 68%, 18 studies). CONCLUSION: POLE mutations in high-grade endometrioid EC are associated with a more favorable prognosis with increased OS and PFS.

Accelerated fragmentation of two thermoplastics (polylactic acid and polypropylene) into microplastics after UV radiation and seawater immersion.

To better understand the fate and assess the ingestible fraction of microplastics (by aquatic organisms), it is essential to quantify and characterize of their released from larger items under environmental realistic conditions. However, the current information on the fragmentation and size-based characteristics of released microplastics, for example from bio-based thermoplastics, is largely unknown. The goal of our work was to assess the fragmentation and release of microplastics, under ultraviolet (UV) radiation and in seawater, from polylactic acid (PLA) items, a bio-based polymer, and from polypropylene (PP) items, a petroleum-based polymer. To do so, we exposed pristine items of PLA and PP, immersed in filtered natural seawater, to accelerated UV radiation for 57 and 76 days, simulating 18 and 24 months of mean natural solar irradiance in Europe. Our results indicated that 76-day UV radiation induced the fragmentation of parent plastic items and the microplastics (50 - 5000 µm) formation from both PP and PLA items. The PP samples (48 ± 26 microplastics / cm2) released up to nine times more microplastics than PLA samples (5 ± 2 microplastics / cm2) after a 76-day UV exposure, implying that the PLA tested items had a lower fragmentation rate than PP. The particles' length of released microplastics was parameterized using a power law exponent (α), to assess their size distribution. The obtained α values were 3.04 ± 0.11 and 2.54 ± 0.06 (-) for 76-day UV weathered PP and PLA, respectively, meaning that PLA microplastics had a larger sized microplastics fraction than PP particles. With respect to their two-dimensional shape, PLA microplastics also had lower width-to-length ratio (0.51 ± 0.17) and greater fiber-shaped fractions (16%) than PP microplastics (0.57 ± 0.17% and 11%, respectively). Overall, the bio-based PLA items under study were more resistant to fragmentation and release of microplastics than the petroleum-based PP tested items, and the parameterized characteristics of released microplastics were polymer-dependent. Our work indicates that even though bio-based plastics may have a slower release of fragmented particles under UV radiation compared to conventional polymer types, they still have the potential to act as a source of microplastics in the marine environment, with particles being available to biota within ingestible size fractions, if not removed before major fragmentation processes.

The PALliative MUlticenter Study in Intensive Care (PalMuSIC). Results From a Multicenter Study Addressing Frailty and Palliative Care Interventions in Intensive Care Units in Portugal.

Objective: Frailty is a clinically recognizable state of increased vulnerability common in critical medicine. When underrecognized, it may lead to invasive treatments that do not serve the patients' best interest. Our aim was to evaluate the use of both palliative care consultation and invasive interventions in frail patients admitted to Intensive Care Units in Portugal. Methods: This was a prospective, observational study. All consecutive adult patients admitted for more than 24 h, over a 15-day period were enrolled. Twenty-three Portuguese Intensive Care Units were included. Informed consent was obtained from all patients or their surrogate. The doctor and nurse in charge calculated the Clinical Frailty Score as well as the reference family member Results: A total of 335 patients were included in the study (66% male). Mean age was 63.2 ± 16.8 and SAPS II score was 41.8 ± 17.4. Mean Clinical Frailty Score value was 3.5 ± 1.7. Frailty prevalence (mean score ≥ 5) was 20.9%. Frail patients were offered organ support therapy (64,3% invasive mechanical ventilation; 24,3% renal replacement therapy; 67,1% vasopressors) more often than non-frail patients. Nevertheless, limitation of therapeutic effort or a do not resuscitate order (p < 0.001) were more common in frail patients. Mortality rate by 6 months was higher among frail patients (50% vs. 32.3%, p < 0.001). Palliative Care was offered to only 15% of frail patients (3.9% overall). Conclusions: The authors suggest that palliative care should be universally consulted once frailty is identified in critical patients.

Typical and atypical carcinoid tumors of the lung: a clinicopathological correlation of 783 cases with emphasis on histological features.

We present 783 surgical resections of typical and atypical carcinoid tumors of the lung identified in the pathology files of 20 different pathology departments. All cases were critically reviewed for clinical and pathological features and further correlated with clinical outcomes. Long-term follow-up was obtained in all the patients and statistically analyzed to determine significance of the different parameters evaluated. Of the histopathological features analyzed, the presence of mitotic activity of 4 mitoses or more per 2 mm2, necrosis, lymphatic invasion, and lymph node metastasis were identified as statistically significant. Tumors measuring 3 cm or more were also identified as statistically significant and correlated with clinical outcomes. Based on our analysis, we consider that the separation of low- and intermediate-grade neuroendocrine neoplasms of the lung needs to be readjusted in terms of mitotic count as the risk of overgrading these neoplasms exceeds 10% under the current criteria. We also consider that tumor size is an important feature to be considered in the assessment of these neoplasms and together with the histological grade of the tumor offers important features that can be correlated with clinical outcomes.

Anecdotal Response to Amphotericin in a Patient with Probable Susac Syndrome: Implications in the Pathogenesis.

Susac syndrome is a rare, probably immune-mediated endotheliopathy presenting with encephalopathy, sensorineural hearing loss and retinal arterial occlusions. A 33-year-old female with Susac syndrome was worsening despite high-dose steroids so a brain biopsy was performed which suggested a possible fungal infection. Treatment with amphotericin B resulted in prompt reversal of symptoms and radiological findings, and no further symptoms occurred during 8 years of follow-up. A diagnosis of fungal infection was not confirmed. The etiology of Susac syndrome is unknown and this anecdotal observation suggests that an infectious agent susceptible to amphotericin might have caused or triggered Susac syndrome in this patient.

A síndrome de Susac é uma endoteliopatia rara, provavelmente imunomediada que se apresenta com a tríade sindromática de encefalopatia, surdez neurosensorial e oclusões de ramos arteriais da retina. Apresenta-se o caso de uma mulher de 33 anos com o diagnóstico de síndrome de Susac que agravou sob terapêutica imunossupressora, pelo que se decidiu pela realização de uma biópsia cerebral, que levantou a suspeita de uma possível infeção fúngica. O tratamento com anfotericina B resultou numa recuperação clínica e imagiológica rápida e não se verificou recorrência de sintomas num período de seguimento de oito anos. O diagnóstico de meningoencefalite fúngica não foi confirmado. A etiologia da síndrome de Susac é desconhecida. A observação fortuita da resposta terapêutica deste caso sugere que um agente infecioso suscetível à anfotericina B possa ter causado ou desencadeado esta síndrome, nesta doente.

Loss of HER2 and disease prognosis after neoadjuvant treatment of HER2+ breast cancer.

INTRODUCTION: HER2 overexpression/amplification occurs in 15-20% breast cancers (BC) and is associated with worse prognosis. The addition of anti-HER2 treatment to neoadjuvant chemotherapy significantly improves the pathological complete response (pCR) rate. Changes in HER2 status after neoadjuvant treatment (NAT) have been reported and may affect prognosis. The aim of this study was to assess the efficacy of NAT in patients with HER2+ BC and its influence on HER2 status and associated prognostic impact. METHODS: Retrospective chart review and pathologic evaluation of all consecutive patients with HER2+ BC (defined as IHC 3+ or IHC 2+ confirmed by SISH) submitted to NAT between 2010-2015 in three Portuguese Hospitals. RESULTS: One hundred eight female patients were included; 40 with stage II, 68 with stage III. Hormone receptors were positive in 70. pCR (ypT0/isN0) was achieved in 48 patients (44%). With a median follow-up of 52 months, there were 5 disease free survival (DFS) events among pCR patients and 19 among non-pCR (P = 0.02). Of the 60 patients with residual disease at surgery, 52 remained HER2+ and 8 (13%) lost HER2 overexpression/amplification. 5y-DFS and 5y-OS was 70% and 84%, respectively, for patients whose residual tumors remained HER2+, and 21% and 50% for patients whose residual tumors became HER2 negative (P = 0.02 and < 0.001). DISCUSSION: We confirmed the negative prognostic impact of NAT-induced HER2 loss on residual tumor leading to worse DFS and OS. Despite the retrospective design and small sample size, these results suggest that it is important to retest HER2 after NAT, to better refine patient outcome.

Bilateral breast fibromatosis after silicone prosthetics in a patient with classic familial adenomatous polyposis: A case report.

Breast fibromatosis is a benign fibroblastic proliferation accounting for less than 0.2% of breast tumors. It presents sporadically or as a manifestation of familial adenomatous polyposis (FAP). Fibromatosis in FAP may develop in patients with adenomatous polyposis coli (APC) gene mutations at any location through the gene. Notably, there is an increased risk if mutation is downstream codon 1400. The present case report described a 33-year-old woman with recurrent bilateral breast fibromatosis after breast implants in a context of classic FAP. APC mutation (codon-935) was detected at the age of 16. In the same year, a thyroidectomy for a cribriform-morular papillary thyroid carcinoma (pT1) was performed. Seven years later, a prophylactic total colectomy with >100 adenomas without invasive carcinoma was performed and the patient was kept under surveillance. At the age of 30 years old, she underwent breast silicone implantation for cosmetic reasons. One year later, bilateral breast tumors were diagnosed in core biopsy as fibromatosis (nuclear ß-catenin+, estrogen receptors-). After no success with medical treatment with tamoxifen, bilateral mastectomy was performed. The patient relapsed one year later and a fibromatosis lesion in the right thoracic wall was excised again. The patient demonstrated no signs of relapse 24 months after the surgery. This rare case illustrates that the increased risk of developing fibromatosis in patients with FAP, even in the classic form, should be considered before deciding to place breast implants.

[Satisfação com o Internato Médico em Portugal]. / Satisfação com o Internato Médico em Portugal.

INTRODUCTION: In the last years, the global context of medical education and Medical Residency programs in Portugal suffered substantial changes. The primary objective of this study was to evaluate and characterize medical residents ́ satisfaction with medical residency programs in Portugal and to identify features that could be improved. MATERIAL AND METHODS: We utilized as model the survey Postgraduate Hospital Educational Environment Measure that has been developed in the United Kingdom and is speci cally targeted to medical residents. The survey was translated and adapted to the Portuguese reality. The survey was available online during April and May of 2016. RESULTS: A total of 3456 responses were obtained, corresponding to a response rate of 35%. Endocrinology/Nutrition, Cardiology, Anesthesiology, Family Physician and Gastroenterology were the specialties in which the degree of satisfaction was higher, while Forensic Medicine, Medical Oncology, Internal Medicine, General Surgery and Pneumology showed the lowest level of satisfaction. DISCUSSION: This study presented a high response rate when compared to previous studies. Portuguese medical residents presented high levels of satisfaction. Depending on year of medical residency, region, type of specialty and type of hospital marked asymmetries were noticed. CONCLUSION: The survey ́s results should constitute in the future a support tool for the implementation of local and national measures relating to the medical residency. It is advisable to regularly conduct satisfaction surveys to medical residents.

Introdução: Nos últimos anos, o contexto global da formação médica, e em particular do Internato Médico em Portugal, sofreu profundas alterações. O presente estudo teve como objetivo avaliar e caracterizar a satisfação dos médicos internos com a realização do Internato Médico em Portugal e identificar aspetos passíveis de melhoria.Material e Métodos: Foi utilizado como modelo de inquérito o questionário Postgraduate Hospital Educational Environment Measuredesenvolvido no Reino Unido e dirigido a médicos internos, o qual foi traduzido e adaptado à realidade portuguesa. O questionário esteve disponível online durante os meses de abril e maio de 2016.Resultados: Foram obtidas 3456 respostas, correspondendo a uma taxa de resposta de 35%. Endocrinologia/Nutrição, Cardiologia, Anestesiologia, Medicina Geral e Familiar e Gastrenterologia foram as especialidades nas quais o grau de satisfação foi mais elevado,enquanto que Medicina Legal, Oncologia Médica, Medicina Interna, Cirurgia Geral e Pneumologia apresentaram o grau de satisfaçãomais baixo.Discussão: O presente estudo apresenta uma elevada taxa de resposta comparativamente com estudos prévios. A nível nacional, no global, os médicos internos apresentaram níveis elevados de satisfação, destacando-se marcadas assimetrias de acordo com o ano de especialidade, região, tipologia de instituição e de especialidade.Conclusão: Os resultados deste inquérito poderão constituir uma ferramenta de apoio à implementação de medidas de âmbito local enacional relacionadas com o Internato Médico, sendo desejável a realização regular de inquéritos de satisfação aos médico internos.

[Abdominal angina due to fibromuscular dysplasia of the celiac axis. Surgical management]. / Angina abdominal por displasia fibromuscular do tronco celíaco. Tratamento cirúrgico.

The clinical case of a 27-year old man with the diagnosis of chronic mesenteric ischemia ("abdominal angina") is reported, whose chief complaints were severe postprandial pain and remarkable weight loss, for the last 4 months. Following na inconclusive observation in gastroenterology, he underwent an angiographic-CT examination, that disclosed a critical stenosis at the origin of the celiac axis. The remaining digestive vessels, superior and inferior mesenteric arteries, were found free of lesions. The patient was submitted to a revascularization procedure, consisting in the celiac axis resection and its replacement by a prosthetic graft, arising from the supraceliac aorta. The post-operative course was uneventfull, followed by a complete remission of the pain and a progressive weight gain. The histopathological study of the removed artery revealed the diagnosis of arterial fibrodysplasia, a very rare entity in clinical practice, of unknown etiology, affecting predominantely young people and in a decreasing order of frequency the renals, the internal carotids and the external iliac arteries. The localization of the fibrodysplastic disease to the celiac áxis seems to be a unique case, never reported before in the literature, thus justifying its publication and dissemination.

Comparative genomic hybridization, BRAF, RAS, RET, and oligo-array analysis in aneuploid papillary thyroid carcinomas.

Aneuploidy in papillary thyroid carcinomas (PTCs) is considered a marker of worse prognosis. Multiple genetic surveys have been performed in PTCs, however, we are not aware of any such studies in aneuploid PTCs. In order to contribute to a better comprehension of the genetic basis of this neoplasm's more aggressive behaviour in 17 aneuploid PTCs we performed a comparative genomic hybridization (CGH) analysis, studied the BRAF and RAS mutational status, searched for RET/PTC1 and RET/PTC3 rearrangements and determined their expression profile. Array results were validated by TaqMan and immunohistochemistry. CGH revealed multiple non-random chromosomal abnormalities. BRAFV600E and RAS mutations were found in 41.2% and 33% of the carcinomas respectively. None of the studied cases presented RET/PTC1 or RET/PTC3 rearrangement. When comparing array data with the chromosomal, mutational and clinical data we found that: a) loss of control of cellular transcription was of major relevance in this group of neoplasms, HMGA2 being one of the most overexpressed genes; b) gene expression correlated with the mutational status of PTCs, as in BRAF+ cases cMET and FN1 were concomitantly overexpressed; and c) death from disease and distant metastasis was associated to the overexpression of DDR2 and to the down-regulation of genes involved in immune, inflammatory response, signal transduction and cell adhesion processes. In conclusion we have identified in aneuploid PTCs a group of significantly altered molecules that may represent preferential targets for the development of new more efficient therapies in this type of cancer.

Mutation analysis of the RET proto-oncogene and early thyroidectomy: results of a Portuguese cancer centre.

BACKGROUND: Evidence that germline mutations in the RET proto-oncogene are the underlying cause of the familial form of medullary thyroid carcinoma (MTC) made it possible to identify gene carriers with a very high degree of accuracy. Aiming to define the mutational profile observed in our patients and to assess gene carriers' compliance with an early surgery, we reviewed results of molecular analysis of RET performed at our institution since 1994. METHODS: One hundred fifty-eight individuals were screened for germline mutations of the RET proto-oncogene. Seventy-seven patients had apparently sporadic MTC; 8 patients had both MTC and pheochromocytoma or MTC and clinical features of multiple endocrine neoplasia type 2B despite a negative family history; 8 patients were known to belong to affected kindreds; and 65 individuals were at-risk individuals to develop MTC. RESULTS: A germline mutation in RET was identified in 4% of apparently sporadic MTC patients, in 100% of patients with MTC and pheochromocytoma or MTC and clinical features of multiple endocrine neoplasia type 2B, and in 100% of probands of clinically established kindreds. The most affected codon was 634 (58%) followed by codon 804 (16%). Among at-risk individuals, 49% were identified as gene carriers. Seven individuals were submitted to prophylactic thyroidectomy (mean age, 17.7 +/- 12.5 years; range: 3-42 years), and all but 1 had MTC. CONCLUSIONS: RET mutational spectrum observed in the present population disclosed a higher frequency of codon 804 mutations than expected. Compliance with an early prophylactic surgery seemed to be influenced not only by medical advice and cultural factors but also by the aggressiveness of disease in gene carriers' families.

A multinodular goiter as the initial presentation of a renal cell carcinoma harbouring a novel VHL mutation.

BACKGROUND: Secondary involvement of the thyroid gland is rare. Often the origin of the tumor is difficult to identify from the material obtained by fine-needle aspiration cytology. Renal cell carcinoma of the clear-cell type is one of the more common carcinomas to metastasize to the thyroid gland. Somatic mutations of the von Hippel-Lindau tumor suppressor gene are associated with the sporadic form of this tumor. We aimed to illustrate the potential utility of DNA based technologies to search for specific molecular markers in order to establish the anatomic site of origin. CASE PRESENTATION: A 54-yr-old Caucasian male complaining of a rapidly increasing neck tumor was diagnosed as having a clear-cell tumor by fine-needle aspiration cytology. A positive staining for cytokeratin as well as for vimentin and CD10 in the absence of staining for thyroglobulin, calcitonin and TTF1 suggested a renal origin confirmed by computed tomography. Using frozen RNA, obtained from cells left inside the needle used for fine needle aspiration cytology, it was possible to identify a somatic mutation (680 delA) in the VHL gene. CONCLUSION: In the presence of a clear-cell tumor of the thyroid gland, screening for somatic mutations in the VHL gene in material derived from thyroid aspirates might provide additional information to immunocytochemical studies and therefore plays a contributory role to establish the final diagnosis. Moreover, in a near future, this piece of information might be useful to define a targeted therapy.

Expression of prolactin receptor and prolactin in normal and malignant thyroid: a tissue microarray study.

OBJECTIVE: There is increasing evidence involving prolactin (PRL) and its receptor (PRLR) in the development of different cancers. The aim of the present study was to investigate the expression of PRLR and PRL in human thyroid tissues. DESIGN AND METHODS: Using tissue microarray (TMA) by immunohistochemical staining, we examined the expression level of PRLR and PRL in 314 specimens from 71 thyroid cancer patients and 15 normal thyroid samples. RESULTS: Expression of the PRLR was observed in 93.3% of normal thyroid samples and in 76.1% of all thyroid cancers, while expression of PRL was observed in only 10% of medullary thyroid carcinomas and not at all in the other specimens, whether normal or neoplastic. Moreover, results suggested an overexpression of PRLR in 70% of medullary thyroid carcinomas, whereas 53.3% of poorly differentiated thyroid carcinomas showed a negative pattern of staining (p = 0.014 vs normal). CONCLUSIONS: Present data revealed, for the first time, a widespread expression of PRLR in normal and neoplastic human thyroid tissues as well as a scarce expression of PRL, observed only in a few medullary thyroid carcinomas. Whether the overexpression of PRLR observed in medullary thyroid carcinomas or the underexpression of PRLR observed in poorly differentiated thyroid carcinomas play a contributory role in the oncogenesis of these tumors remains to be determined.

Expression of vascular endothelial growth factor (VEGF) and its receptors in thyroid carcinomas of follicular origin: a potential autocrine loop.

OBJECTIVE: The aim of this study was to clarify the role of vascular endothelial growth factor (VEGF) and VEGF receptor (VEGFR) pathways in thyroid tumourigenesis. METHODS: We examined VEGF, VEGFR-1 and VEGFR-2 expression on 34 papillary thyroid carcinomas (PTCs), 18 follicular thyroid carcinomas (FTCs), eight poorly differentiated thyroid carcinomas (PDTCs) and on a thyroid tumour-derived cell line (NPA'87) by immunohistochemistry, reverse transcriptase PCR, immunofluorescence and Western blotting. RESULTS: We have demonstrated that VEGF expression was significantly (P < 0.05) more prevalent in PTCs (79%) than in FTCs (50%) or PDTCs (37%). Similarly, 76% of PTCs, 83% of FTCs and 25% of PDTCs expressed VEGFR-1, whereas 68% of PTCs, 56% of FTCs and 37% of PDTCs expressed VEGFR-2. Coexpression of VEGF and its receptors was observed in 50% of PTCs, 39% of FTCs and 12% of PDTCs, raising the possibility that VEGF may signal in an autocrine loop in these neoplasias, as observed previously for other types of cancer. In agreement with the idea that autocrine VEGF signalling plays an important role in thyroid carcinogenesis, the blockade of either VEGF or its receptors with neutralizing antibodies significantly reduced cell viability and increased apoptosis levels of the VEGFR-positive thyroid tumour cell line NPA'87. CONCLUSIONS: Our results highlight a previously undefined VEGF autocrine action in thyroid carcinomas which could play a crucial role in tumour cell survival and could represent a useful therapeutic target for thyroid tumours.

Immunostaining and RT-PCR: different approaches to search for RET rearrangements in patients with papillary thyroid carcinoma.

Different techniques of molecular biology have been used to screen for RET rearrangements. More recently, immunohistochemistry has been used, assuming that RET is not expressed in normal thyroid follicular cells. The present study was designed to define the prevalence of RET expression in patients with papillary thyroid carcinoma, by immunohistochemistry and by RT-PCR; to search specifically for RET/PTC-1; -2; -3 rearrangements using RT-PCR, and to compare results obtained by immunohistochemistry with those obtained by RT-PCR. Immunohistochemistry was performed using a polyclonal antibody against tyrosine kinase domain of Ret protein. Screening for RET/PTC1-3 was performed using RT-PCR and specific primers for each rearrangement; complementarily, a subset of cases were tested using RET exon 10/11 primers designed to detect the expression of the wild-type RET. Positive staining was observed in 30 of 39 (77%) tumours. RET/PTC1-3 rearrangements were detected in 8 of 32 (25%) cases. Ten of 15 (67%) cases expressed the wild-type RET. Two tumours characterised by positive immunostaining, absence of RET 5' expression and absence of RET/PTC1-3 expression were considered as expressing a RET rearrangement different from RET/PTC-1, -2, or -3. In 3 of 10 tumours, expression of the wild-type RET coexisted with the expression of a RET rearrangement. Positive staining does not necessarily mean the presence of a rearrangement; it may correspond to the expression of the wild-type RET, RET rearrangement or both. On the contrary, positive staining without evidence for the expression of the extracellular domain of RET is highly suggestive of a RET rearrangement independently of the type. Refinement of diagnosis depends on RT-PCR with specific primers.

Loss of heterozygosity in follicular and papillary thyroid carcinomas.

In this study we aimed at investigating the incidence and the role of 3p deletions, particularly at the 3p25 approximately pter region, in follicle cell-derived thyroid neoplasms, by using loss of heterozygosity (LOH) analysis. We analyzed 12 follicular adenomas (FA), 13 follicular thyroid carcinomas (FTC), and 15 papillary thyroid carcinomas (PTC) with 11 microsatellite markers for chromosome 3. One additional marker on 3q25.2 was also investigated for assessment of deletion extent on 3q. Microsatellite instability was detected at one locus in 1 of 15 PTC (7%) and at four loci in 1 of 13 FTC (8%). Loss of heterozygosity was found in 8 of 12 cases of FTC (67%), in 6 of 15 cases of PTC (40%), and in 2 of 12 FA (17%). We identified three minimal common deleted regions (CDR) involving significant sites of LOH: two in FTC (a new terminal region, of approximately 8 cM distal to D3S1620 at 3p25.3 approximately pter and the D3S1573-D3S1595 region at 3p21.2 approximately p12) and one in PTC (D3S1304-D3S1263 region at 3p25.3 approximately p24.2). The newly identified 3p25.3 approximately pter CDR seems to be specific for FTC. Our results suggest the existence of at least three distinct regions on 3p that might harbor tumor suppressor genes involved in the carcinogenesis processes of FTC and PTC.