A Review of Parathyroid Surgery for Primary Hyperparathyroidism from the United Kingdom Registry of Endocrine and Thyroid Surgery (UKRETS)

BACKGROUND

The United Kingdom Registry of Endocrine and Thyroid Surgeons is a national database holding details on > 28,000 parathyroidectomies.

METHODS

An extract (2004-2017) of the database was analysed to investigate the reported efficacy, safety and use of intra-operative surgical adjuncts in targeted parathyroidectomy (tPTx) and bilateral neck exploration (BNE) for adult, first-time primary hyperparathyroidism (PHPT).

RESULTS

50.9% of 21,738 cases underwent tPTx. Excellent short-term (median follow-up 35 days) post-operative normocalcaemia rates were reported overall (tPTx 96.6%, BNE 94.5%, p < 0.05) and in image-positive cases (tPTx 96.7%, BNE 96%, p < 0.05). Intra-operative PTH improved overall normocalcaemia rates (tPTx 97.8% vs 96.3%, BNE 95% vs 94.4%: both p < 0.05). Intra-operative nerve monitoring reduced vocal cord (VC) dysfunction in image-positive tPTx, but not in BNE (97.8% vs 93.2%, p < 0.05). Complications were higher following BNE (7.4% vs 3.8%, p < 0.05), especially hypocalcaemia (5.3% vs 2%, p < 0.05). There was no difference in rates of subjective dysphonia following tPTx or BNE (2.4% vs 2.3%, p > 0.05), nor any difference in VC dysfunction when formally examined (4.9% vs 4.1%, p > 0.05).

CONCLUSIONS

In image-positive, first time, adult PHPT cases, tPTx is as safe and effective as BNE, with both achieving excellent short-term results with minimal complications.

Systematic review of cure and recurrence rates following minimally invasive parathyroidectomy

Background

The majority of patients with primary hyperparathyroidism (PHPT) have a single overactive adenoma. Advances in preoperative imaging and surgical adjuncts have given rise to minimally invasive parathyroidectomy (MIP), with lower complication rates in comparison with bilateral neck exploration. Misdiagnosis and undertreatment of multiglandular disease, leading to potentially higher recurrence rates, remains a concern. This study evaluated risks of long‐term (1 year or more) recurrence following ‘targeted’ MIP in PHPT.

Methods

Multiple databases were searched for studies published between January 2004 and March 2017, looking at long‐term outcomes (1 year or more) following targeted MIP for PHPT. English‐language studies, with at least 50 patients and a mean follow‐up of 1 year, were included.

Results

A total of 5282 patients from 14 studies were included. Overall mean recurrence and cure rates were 1·6 (range 0–3·5) and 96·9 (95·5–100) per cent respectively. Mean follow‐up was 33·5 (1–145) months. When intraoperative parathyroid hormone (PTH) measurements were not done, cure rates were higher (99·3 per cent versus 98·1 per cent with use of intraoperative PTH measurement; P < 0·001) and recurrence rates lower (0·2 versus 1·5 per cent respectively; P < 0·001).

Conclusion

Targeted MIP for a presumed single overactive adenoma was associated with very low recurrence rates, without the need for intraoperative PTH measurement when preoperative imaging studies were concordant. Targeted MIP should be encouraged.

Manipulation of PBF/PTTG1IP phosphorylation status; a potential new therapeutic strategy for improving radioiodine uptake in thyroid and other tumors

CONTEXT

The clinical effectiveness of ablative radioiodine treatment of thyroid tumors is limited by the availability of the sodium iodide symporter (NIS) at the plasma membrane (PM) for uptake of ¹³¹I. A significant proportion of well-differentiated thyroid tumors are unable to concentrate sufficient radioiodine for effective therapy, and in other tumor models such as breast tumors, where radioiodine uptake would be an attractive therapeutic option, uptake is insufficient.

OBJECTIVE

Pituitary tumor-transforming gene-binding factor (PBF; PTTG1IP) is overexpressed in multiple cancers and significantly decreases NIS expression at the PM. The goal of this study was to identify a method by which PBF repression of NIS may be overcome in human tumors.

RESULTS

Here, we identify PBF as a tyrosine phosphoprotein that specifically binds the proto-oncogene tyrosine protein kinase Src in mass spectrometry, glutathione S-transferase pulldown and coimmunoprecipitation assays. Src induction leads to phosphorylation at PBF residue Y174. Abrogation of this residue results in PM retention and a markedly reduced ability to bind NIS. The Src inhibitor PP1 inhibits PBF phosphorylation in multiple cell lines in vitro, including human primary thyroid cells. Of direct clinical importance to the treatment of thyroid cancer, PP1 stimulates iodide uptake by transfected NIS in TPC1 thyroid carcinoma cells and entirely overcomes PBF repression of iodide uptake in human primary thyroid cells.

CONCLUSIONS

We propose that targeting PBF phosphorylation at residue Y174 via tyrosine kinase inhibitors may be a novel therapeutic strategy to enhance the efficacy of ablative radioiodine treatment in thyroid and other endocrine and endocrine-related tumors.

PTTG and PBF repress the human sodium iodide symporter

The ability of the thyroid to accumulate iodide provides the basis for radioiodine ablation of differentiated thyroid cancers and their metastases. Most thyroid tumours exhibit reduced iodide uptake, although the mechanisms accounting for this remain poorly understood. Pituitary tumour transforming gene (PTTG) is a proto-oncogene implicated in the pathogenesis of thyroid tumours. We now show that PTTG and its binding factor PBF repress expression of sodium iodide symporter (NIS) messenger RNA (mRNA), and inhibit iodide uptake. This process is mediated at least in part through fibroblast growth factor-2. In detailed studies of the NIS promoter in rat FRTL-5 cells, PTTG and PBF demonstrated specific inhibition of promoter activity via the human upstream enhancer element (hNUE). Within this approximately 1 kb element, a complex PAX8-upstream stimulating factor 1 (USF1) response element proved critical both to basal promoter activity and to PTTG and PBF repression of NIS. In particular, repression by PTTG was contingent upon the USF1, but not the PAX8, site. Finally, in human primary thyroid cells, PTTG and PBF similarly repressed the NIS promoter via hNUE. Taken together, our data suggest that the reported overexpression of PTTG and PBF in differentiated thyroid cancer has profound implications for activity of the NIS gene, and hence significantly impacts upon the efficacy of radioiodine treatment.

Pituitary tumor transforming gene (PTTG) stimulates thyroid cell proliferation via a vascular endothelial growth factor/kinase insert domain receptor/inhibitor of DNA binding-3 autocrine pathway

CONTEXT

Vascular endothelial growth factor (VEGF) exerts its biological effects by binding to the tyrosine kinase receptors VEGF receptor type 1 (VEGFR1/Flt-1) and VEGFR2 (Flk-1/KDR). Kinase insert domain receptor (KDR) is the critical receptor controlling proliferation and migration of endothelial cells and has been shown to be expressed in some nonendothelial cells. We recently reported that the proangiogenic pituitary tumor transforming gene (PTTG) stimulates VEGF and up-regulates inhibitor of DNA binding-3 (ID3), an important gene in VEGF-dependent angiogenesis.

OBJECTIVE

Our objective was to test whether VEGF, ID3, and KDR confer a PTTG-mediated effect on thyroid cell growth.

DESIGN

Gene expression, MAPK stimulation, and cell proliferation were assessed in follicular thyroid cancer FTC133 cells. Gene expression and clinical associations were determined in 21 normal and 38 tumorous thyroid specimens (nine follicular and 29 papillary).

RESULTS

ID3 correlated with VEGF mRNA expression in our series of thyroid cancers, which also showed up-regulated KDR mRNA. Stimulation of FTC133 cells with exogenous VEGF enhanced ID3 expression, which could be abrogated by the KDR-specific inhibitor ZM323881, suggesting that VEGF regulation of ID3 is KDR dependent. PTTG significantly correlated with KDR mRNA expression in our thyroid cancer cohort and up-regulated KDR and VEGF expression in FTC133 cells. Finally, cells transfected with PTTG demonstrated increased cell proliferation and phosphorylation of MAPK, which was abrogated by ZM323881.

CONCLUSIONS

We report the presence of a VEGF/KDR/ID3-dependent autocrine pathway in FTC133 thyroid cells. By up-regulating both VEGF and KDR expression, we propose a novel PTTG-mediated proliferative pathway that may be critical to thyroid cancer growth and progression.

Serum thyrotropin concentration as a novel predictor of malignancy in thyroid nodules investigated by fine-needle aspiration

CONTEXT

Thyroid nodules and goiter are common, and fine-needle aspiration biopsy (FNAB) is the first investigation of choice in distinguishing benign from malignant disease.

OBJECTIVE

The objective of the study was to assess whether simple clinical and biochemical parameters can predict the likelihood of thyroid malignancy in subjects undergoing FNAB.

DESIGN

The design was a prospective cohort.

SETTING

The study was conducted at a single secondary/tertiary care clinic.

PARTICIPANTS

One thousand five hundred consecutive patients without overt thyroid dysfunction (1304 females and 196 males, mean age 47.8 yr) presenting with palpable thyroid enlargement between 1984 and 2002 were evaluated by FNAB of the thyroid.

INTERVENTION(S)

There were no interventions.

MAIN OUTCOME MEASURES

Goiter type was assessed clinically and classified as diffuse in 183, multinodular in 456, or solitary nodule in 861 cases. Serum TSH concentration at presentation was measured in a sensitive assay in patients presenting after 1988 (n = 1183). The final cytological or histological diagnosis was determined after surgery (n = 553) or a minimum 2-yr clinical follow-up period (mean 9.5 yr, range 2-18 yr).

RESULTS

The overall sensitivity and specificity of FNAB in predicting malignancy were 88 and 84%, respectively. The risk of diagnosis of malignancy rose in parallel with the serum TSH at presentation, with significant increases evident in patients with serum TSH greater than 0.9 mU/liter, compared with those with lower TSH. Binary logistic regression analysis revealed significantly increased adjusted odds ratios (AORs) for the diagnosis of malignancy in subjects with serum TSH 1.0-1.7 mU/liter, compared with TSH less than 0.4 mU/liter [AOR 2.72, 95% confidence interval (CI) 1.02-7.27, P = 0.046], with further increases evident in those with TSH 1.8-5.5 mU/liter (AOR 3.88, 95% CI 1.48-10.19, P = 0.006, compared with TSH < 0.4 mU/liter) and greater than 5.5 mU/liter (AOR 11.18, 95% CI 3.23-8.63, P < 0.001, compared with TSH < 0.4 mU/liter). Males (AOR 1.8, 95% CI 1.04-3.1, P = 0.04), younger patients (AOR 1.1, 95% CI 1.01-1.15, P = 0.025), and those with clinically solitary nodules (AOR 2.53, 95% CI 1.5-4.28, P = 0.001) were also at increased risk. Based on these findings, a formula to predict the risk of the diagnosis of thyroid malignancy in individual patients, taking into account their gender, age, goiter type determined clinically, and serum TSH, was calculated.

CONCLUSIONS

The risk of malignancy in a thyroid nodule increases with serum TSH concentrations within the normal range. In addition to patient's gender, age, and goiter type, the serum TSH concentration at presentation is an independent predictor of the presence of thyroid malignancy. We propose that these simple clinical and biochemical factors can serve as an adjunct to FNAB in predicting risk of malignancy.

Securin induces genetic instability in colorectal cancer by inhibiting double-stranded DNA repair activity

Genetic instability (GI) is a hallmark feature of tumor development. Securin, also known as pituitary tumor transforming gene (PTTG), is a mitotic checkpoint protein which is highly expressed in numerous cancers, is associated with tumor invasiveness, and induces GI in thyroid cells. We used fluorescence inter-simple sequence repeat PCR to assess GI caused primarily by DNA breakage events in 19 colorectal tumors. GI values ranged significantly, with Dukes' stage C&D colorectal tumors exhibiting greater GI and higher securin expression than Dukes' stage A&B tumors. Consistent with these findings, we observed a dose-dependent increase in GI in HCT116 cells in response to securin overexpression, as well as in non-transformed human fibroblasts. As securin has been implicated in a novel DNA repair pathway in fission yeast, we investigated its potential role in chemotoxic DNA damage response pathways in mammalian cells, using host cell reactivation assays. Securin overexpression in HCT116 cells inhibited etoposide-induced double-stranded DNA damage repair activity, and repressed Ku heterodimer function. Additionally, we observed that securin and Ku70 showed a reciprocal cytosol-nuclear translocation in response to etoposide-induced dsDNA damage. Our data suggest that, by repressing Ku70 activity and inhibiting the non-homologous end-joining dsDNA repair pathway, securin may be a critical gene in the development of GI in colorectal cancer.

Pituitary tumor-transforming gene regulates multiple downstream angiogenic genes in thyroid cancer

CONTEXT

Pituitary tumor-transforming gene (PTTG) is a multifunctional protein involved in several tumorigenic mechanisms, including angiogenesis. PTTG has been shown to promote angiogenesis, a key rate-limiting step in tumor progression, by up-regulation of fibroblast growth factor-2 and vascular endothelial growth factor.

OBJECTIVE

To investigate whether PTTG regulates other angiogenic genes in thyroid cells, we performed angiogenesis-specific cDNA arrays after PTTG transfection. Two of the genes [inhibitor of DNA binding-3 (ID3) and thrombospondin-1 (TSP-1)] which showed differential expression in primary thyroid cells were validated in vitro and in vivo.

RESULTS

TSP-1 showed a 2.5-fold reduction and ID3 showed a 3.5-fold induction in expression in response to PTTG overexpression in vitro. Conversely, suppression of PTTG with small interfering RNA was associated with a 2-fold induction of TSP-1 and a 2.2-fold reduction in ID3 expression. When we examined TSP-1 and ID3 expression in 34 differentiated thyroid cancers, ID3 was significantly increased in tumors compared with normal thyroid tissue. Furthermore, ID3 expression was significantly higher in follicular thyroid tumors than in papillary tumors. Although mean TSP-1 expression was not altered in cancers compared with normal thyroids, we observed a significant independent association between TSP-1 expression and early tumor recurrence, with recurrent tumors demonstrating 4.2-fold lower TSP-1 expression than normal thyroid tissues.

CONCLUSION

We have identified ID3 and TSP-1 as two new downstream targets of PTTG in thyroid cancer. We propose that PTTG may promote angiogenesis by regulating the expression of multiple genes with both pro- and antiangiogenic properties and may thus be a key gene in triggering the angiogenic switch in thyroid tumorigenesis.

Carboplatin and Hypofractionated Accelerated Radiotherapy: A Dose Escalation Study of an Outpatient Chemoradiation Schedule for Squamous Cell Carcinoma of the Head and Neck

AIM

To examine the feasibility and determine the maximum tolerated dose of outpatient carboplatin given with synchronous hypofractionated accelerated radiotherapy for squamous cell carcinoma of the head and neck (SCCHN).

MATERIALS AND METHODS

Patients with stages II-IV SCCHN and unresected primary tumour were treated with synchronous carboplatin given in an outpatient setting on day 1 and day 21 in cohorts of three to six patients with incremental area under curve (AUC) factors commencing at 3.5. Grade 3 mucositis persisting for 4 weeks in two patients in a cohort was considered dose limiting.

RESULTS

A total of 19 patients were enrolled and assessable for toxicity. All 19 patients completed 55 Gy of radiotherapy and were assessable for response. Grade 3 mucositis lasting 4 weeks or more was seen in three patients, two of them received AUC 5 carboplatin. A complete response was seen in 16 patients, with a further patient having a partial response, giving a response rate of 89%. With a median follow-up of 24 months (range 11-30 months), 13 patients were alive with no evidence of recurrent disease. Local recurrence had occurred in four patients with distant spread in three patients.

CONCLUSION

Carboplatin with concurrent hypofractionated accelerated radiotherapy is feasible for patients with advanced SCCHN and good performance status. The recommended phase II dose of carboplatin given in week 1 and week 4 with 55 Gy in 20 fractions is AUC 4.5.

The management of squamous cell carcinoma of the neck. The Birmingham UK experience

AIMS

To review our treatment strategy and outcomes for metastatic squamous cell carcinoma of the neck.

METHODS

One hundred and six consecutive patients treated between 1992 and 1998 were analysed retrospectively. The following data were obtained. Demographic details, tumour site, clinical and pathological TMN staging, tumour grade and presence of extracapsular spread, treatment modality (surgery, radiotherapy and chemotherapy), type of neck dissection and complications, 2-year loco-regional control and 5-year overall survival.

RESULTS

Ninety-two patients had advanced disease (stages 3 and 4) and of these, 57% had palpable neck metastases. One hundred and six patients underwent a total of 132 neck dissections. Seventy-three patients had post-operative radiotherapy to both sides of the neck and a total of 31 patients took part in the UKHAN 1 trial. Seventy percent of patients achieved 2-year loco-regional control and 63% survived 5-years.

CONCLUSION

Metastatic squamous cell carcinoma of the neck can successfully be treated with an aggressive surgical approach and post-operative radiotherapy when indicated. Excellent 2-year loco-regional control and 5-year survival rates are possible.

Oncogenes in thyroid cancer

There have been significant advances in our understanding of carcinogenesis at the molecular level over the last 25 years. Oncogenes are of major interest as part of our search for knowledge surrounding the aetiology of cancer. There are several oncogenes associated with thyroid cancer. Detailed investigation of the nature and function of these tumour genes has provided important insights into both the tumour biology and the complex biochemical pathways of normal cellular functioning. Our knowledge of oncogene biology offers the hope of better diagnostic, therapeutic and prognostic modalities in our fight against this and other common cancers. Development of specific thyroid tumour markers and gene therapy is now a realistic prospect to supplement our present armamentarium of surgery and radiotherapy. This review aims to outline the pertinent information gained so far from studies of these oncogenes and provides both clinical relevance and fuel for further interest amongst the ENT thyroid community in this exciting area of research.

External Beam Radiotherapy in the Management of Differentiated Thyroid Cancer

AIMS

No randomised trials have addressed the use of external beam radiotherapy (EBRT) in the treatment of differentiated thyroid cancer. The indications for EBRT, the technique and recommended dose all remain controversial.

MATERIALS AND METHODS

We included patients treated with EBRT with curative intent from two cancer centres between 1988 and 2001. Data were collected from hospital notes, radiotherapy prescriptions and local cancer registry.

RESULTS

The indications for treatment in the 41 identified patients were macroscopic residual disease 23 (56%), microscopic residual disease 10 (25%), Hurthle cell variants 3 (7%), multiple lymph-node involvement 3 (7%) and other 2 (5%). Delivered doses ranged from 37.5-66 Gy over 3-6.5 weeks. Rate of local recurrence and overall survival at 5 years were as follows: papillary 26% and 67%; follicular 43% and 48%; well differentiated 21% and 67%; focus of poor differentiation/Hurthle cell variants 69% and 32%; complete excision 25% and 61%; residual disease 37% and 59%; EBRT total dose < 50 Gy 63% and 42%; 50-54 Gy 15% and 72%; > 54 Gy 18%, and 68%.

CONCLUSIONS

The results in this study are consistent with previous retrospective studies of EBRT. The wide range of indications and doses used with radical intent highlights the lack of clinical and radiobiological data on the response of differentiated thyroid cancer to EBRT. Despite the small study size, the 5-year local recurrence results indicate a possible dose response within the dose range used.

Pituitary tumor transforming gene and fibroblast growth factor-2 expression: potential prognostic indicators in differentiated thyroid cancer

Differentiated thyroid cancers are the most common endocrine cancers, but there are no reliable molecular markers of prognosis. Pituitary tumor transforming gene (PTTG) plays several potential roles in tumor initiation and progression, including regulating mitosis and stimulating expression of fibroblast growth factor (FGF)-2. Increased expression of PTTG has been demonstrated in follicular thyroid lesions, and expression of this oncogene has been identified as a potential prognostic marker in pituitary adenomas and colon carcinomas. We assessed the expression of PTTG and FGF-2 and its receptor FGF-R-1 in 27 differentiated thyroid cancers, and we compared this with expression in 11 normal thyroids, 25 multinodular goiters, and 13 Graves' disease specimens. We also examined the relationship between gene expression and clinical markers of tumor behavior. PTTG and FGF-2 were overexpressed in thyroid carcinomas (9.5-fold increase, P = 0.003, and 5.0-fold increase, P < 0.001, respectively) compared with normal thyroid. Increased FGF-2 mRNA expression was independently associated with the findings of lymph node invasion (R(2) = 0.71; P < 0.001) and distant metastasis (R(2) = 0.55; P = 0.009) at tumor presentation, after taking into account known prognostic factors such as age and gender of the patient and size and type of the tumor. High PTTG expression was independently associated with tumor recurrence (R(2) = 0.64; P = 0.003). We conclude that PTTG and FGF-2 expression are potential prognostic markers (and perhaps therapeutic targets) for differentiated thyroid cancer.

Conservation surgery in the management of T1 and T2 oropharyngeal squamous cell carcinoma: the Birmingham UK experience

The aim of this paper was to evaluate our experience using conservation surgery in the management of T1 and T2 oropharyngeal squamous cell carcinoma. Eighteen patients underwent conservation surgery between 1993 and 2000 and were analysed retrospectively. The mean age was 54 years and the male to female ratio was 8:1. There were 14 tonsil and 4 tongue base tumours and 83% of cases presented with neck nodes, thereby classifying them as having advanced disease (stages 2-4). All patients received postoperative radiotherapy. All patients were followed up to December 2001. The median follow-up time was 3.8 years (minimum was 1.5 years). The 2-year and 5-year survival rates were 100% and 92% respectively. Approximately 66% of patients returned the EORTC and GHQ/12 quality-of-life questionnaires. Of these, seventy-five percent had a high healthy level of general functioning in accordance with the EORTC general health section. These results show that conservation surgery techniques are effective in the treatment of T1 and T2 oropharyngeal squamous carcinoma associated with significant metastatic neck disease. The techniques are well tolerated, produce minimal functional deficit and do not have a negative impact on the patients quality of life in either the immediate postoperative period or up to 4 years post-treatment.

Who performs thyroid surgery: a review of current otolaryngological practice

Thyroid surgery has been traditionally a general surgical practice, but recently more otolaryngologists have been offering a thyroid service. We have quantified thyroid surgery performed by the different specialties, and looked more closely at the practice of otolaryngologists. Data was obtained from the Department of Health for UK thyroid surgery in all specialties for the year 1998-99 and validated against a survey of members of the British Association of Otolaryngologists-Head & Neck Surgeons (BAO-HNS). The use of investigations of a simple clinical case (solitary thyroid nodule) was compared with best practice. General surgeons still perform the majority of thyroid surgery (83%) but ENT surgeons now perform significant numbers (15.4% of all cases), which translates to 1499 cases per annum. A total of 102 BAO-HNS members were performing thyroid surgery with an average case-load of 19.1 per year. In total, 35% of ENT surgeons see thyroid patients in multidisciplinary clinics. The choice of investigation is consistent with European guidelines. ENT surgeons are doing significant amounts of thyroid surgery and the numbers appear to be increasing. The formation of multidisciplinary teams including general surgeons and otolaryngologists who are committed to subspecialization can only improve both training and treatment outcomes.

Thyroid follicular cells secrete plasminogen activators and can form angiostatin from plasminogen

Angiostatin, a 38 kDa fragment of plasminogen, potently inhibits the growth of blood vessels. Angiostatin is generated from plasminogen by urokinase-type (uPA) and tissue-type (tPA) plasminogen activators in the presence of free sulphydryl donors. Angiogenesis inhibitors may be important in regulating angiogenesis in developing goitre. We have examined angiostatin formation in human primary thyrocyte cultures and a rat thyrocyte cell line (FRTL-5). We found that human thyroid cells in culture secrete plasminogen activators (both tPA and uPA) as well as matrix metalloproteinase 2 into the medium. When human thyrocyte conditioned medium was incubated with plasminogen (10 microg/ml) and N-acetylcysteine (100 microM) for 24 h, a 38 kDa fragment of plasminogen, which is consistent with angiostatin, was generated. The appearance of the 38 kDa fragment was increased by agents that increase cAMP (forskolin and 8 BrcAMP). FRTL-5 cells, which do not secrete uPA or tPA, did not generate angiostatin. Thyroid cells produce several angiogenic growth factors, and human thyrocyte conditioned medium stimulated growth of endothelial cells. When the conditioned medium was incubated with plasminogen and N-acetylcysteine, this stimulatory effect was lost, consistent with the production of a growth inhibitory factor. We conclude that thyroid cells can produce angiostatin from plasminogen in vitro, and this may play a role in vivo in limiting goitre size.

Fourth branchial arch fistula and suppurative thyroiditis: a life-threatening infection

A potentially life-threatening case of recurrent left-sided thyroid abscess formation secondary to a fourth branchial arch sinus fistula is presented. The patient developed a reversible left vocal fold palsy during an acute episode of suppurative thyroiditis requiring a temporary tracheostomy due to a compromised airway. Investigations commonly used to demonstrate this anomaly may fail to confirm the diagnosis as in the case presented and exploratory surgery with excision of the fistulous tract should still be considered. We describe a method of repairing the pharyngeal opening to reduce the risk of recurrence or pharyngeal leak.

Solitary fibrous tumour of the thyroid gland

Solitary fibrous tumours of the thyroid gland are rare; only five cases have been reported in the literature. Clinically, they present as a long-standing firm mass in the thyroid. Histologically, they show a range of appearances including so-called 'patternless growth pattern', spindle-cell morphology, alternating hypo- and hyper-cellular areas, keloid-like hyalinization and a prominent haemangiopericytoma - like architecture. The behaviour of extrathoracic solitary fibrous tumours is unpredictable and requires careful, long-term follow-up.

Tie-2 is expressed on thyroid follicular cells, is increased in goiter, and is regulated by thyrotropin through cyclic adenosine 3',5'-monophosphate

Angiogenesis is coordinated with follicular cell growth in goitrogenesis. The angiopoietins, Ang-1 and Ang-2, are angiogenic growth factors acting through Tie-2, a tyrosine kinase receptor. We have examined the expression and regulation of the angiopoietins and Tie-2 in human and rat thyroids. In human goiters there was increased Tie-2 immunostaining, compared with that in normal thyroids, on both follicular and endothelial cells. In an induced goiter in rats, in situ hybridization showed increased expression of messenger ribonucleic acids (mRNAs) for Tie-2 and Ang-1 in follicular cells. As Tie-2 has previously been believed to be restricted to cells of endothelial lineage in adults, we examined its expression further in isolated follicular cells. Tie-2 and Ang-1 mRNA expression in human thyrocytes was confirmed by ribonuclease protection assay. Ang-2 mRNA was not detected in human cultures or rat thyroids. In both human follicular cell cultures and FRTL-5 cells, immunoblotting showed that Tie-2 expression was increased by TSH and agents that increased intracellular cAMP. In conclusion, we have demonstrated the expression of Tie-2 and Ang-1 in thyroid epithelial and endothelial cells, and have shown the regulation of Tie-2 by TSH and cAMP in follicular cells. Tie-2 expression is increased in goiter in both humans and rats, consistent with a role in goitrogenesis.

An audit of management of differentiated thyroid cancer in specialist and non-specialist clinic settings

OBJECTIVE

Thyroid cancer is the most common endocrine malignancy but is none the less rare. Some aspects of its management remain controversial. Previous audits of patient management in the United Kingdom have revealed deficiencies, especially in communication between specialists. We have audited patient management in a large university-associated teaching hospital, assessing points of good practice identified from published guidelines and reviews, and have compared findings in groups of patients managed jointly by specialists with an interest in thyroid cancer (including surgeon, endocrinologist and oncologist) with a group managed by other clinicians outside that setting.

DESIGN AND PATIENTS

Retrospective case-note review of 205 patients with differentiated (papillary or follicular) cancer including group A (n = 134; managed in a specialist multi-disciplinary clinic setting) and group B (n = 71; managed in other clinic settings). Points of good practice investigated were adequacy of surgery, surgical complications, prescription and adequacy of T4 treatment, adequacy of monitoring by measurement of serum thyroglobulin and action taken and appropriate administration of ablative radioiodine.

RESULTS

Deficiencies in management of the cohort as a whole were identified, including inadequate surgery and inadequate TSH suppression in approximately one-fifth of the cases. Monitoring with thyroglobulin measurements and action when serum thyroglobulin was high were also inadequate in some cases and ablative radioiodine was not given, despite being indicated in 11.7% of the cohort. Inadequate surgery and failure to administer radioiodine were less common in those managed in a specialist clinic setting than in those managed in other clinic settings.

CONCLUSIONS

The findings highlight the need for locally agreed protocols in managing relatively rare endocrine disorders such as thyroid cancer and argue in favour of centralization of expertise and patient management in multi-disciplinary specialist clinic settings.

The aetiology of nasopharyngeal carcinoma

Nasopharyngeal carcinoma is a disease with a remarkable racial and geographical distribution. In most parts of the world it is a rare condition and in only a handful of places does this low risk profile alter. These include the Southern Chinese, Eskimos and other Arctic natives, inhabitants of South-East Asia and also the populations of North Africa and Kuwait.

Thyroid stimulating hormone increases angiogenic growth factor expression in rat thyrocytes

INTRODUCTION: Goitrogenesis is thought to be due to hyperstimulation of the thyroid stimulating hormone (TSH) receptor and is associated with dramatic andiogenesis within the thyroid. The angiogenic growth factors, fibroblast growth factor (FGF-2) and its receptor (FGFR-1) as well as Tie-2 (the receptor for the angiopoietins) are elevated in both the human goitre and in rat goitre. We have investigated the role of TSH in the expression of FGF-2, FGFR-1 and Tie-2 in FRTL-5 cells, which are a functional rat thyroid cell line. METHODS: Cells were cultured in medium containing 5% serum, insulin and antibodies and exposed to a variety of experimental conditions. Proteins were separated by electrophoresis and analysed by Western blotting using polyclonal antibodies to FGFR-1 (extracellular domain, Santa Cruz), Tie-2 (Santa Cruz) and FGF-2 (Sigma). RESULTS: TSH increased expression of FGF-2 reaching a maximum at 0.3 mU/ml returning to control levels at higher concentrations. A dominant fragment of its receptor (FGFR-1) at >> 57 kDa was dose-dependently increased by TSH. Tie-2 was thought to be predominantly expressed on endothelial cells but we now show that it is expressed as a full-length receptor on FRTL-5 cells with maximal expression at 0.3 mU/ml. This regulation is mediated by cAMP as forskolin and 8-Bromo-cAMP also increased Tie-2 expression. CONCLUSION: Both FGF-2 and its receptor, as well as Tie-2 are increased in rat thyroid cells by elevated TSH. These mechanisms may be central to the angiogenesis that occurs in goitrogenesis, and alteration of these growth factors may lead to new treatments for goitre.

Gender, clinical findings, and serum thyrotropin measurements in the prediction of thyroid neoplasia in 1005 patients presenting with thyroid enlargement and investigated by fine-needle aspiration cytology

One thousand five euthyroid patients (870 females and 135 males, mean age 47 years), who presented with thyroid enlargement were evaluated by fine-needle aspiration cytology (FNAC) of the thyroid as the first-line investigation. The final cytological or histological diagnosis was determined after surgery (n = 312) or clinical follow-up for a minimum period of 2 years (range 2-14 years, mean 6.7 years). Goiter type was assessed clinically and was classified as diffuse in 147, multinodular in 247, or solitary nodule in 611. The overall sensitivity and specificity of the procedure in the detection of thyroid neoplasia was 88% and 89%, respectively. Males who presented with thyroid enlargement had significantly higher rates of malignancy (p = 0.007) and neoplasia (benign + malignant) (p = 0.002) than females, as did subjects with solitary nodule compared with diffuse or multinodular goiters (malignancy p = 0.001, neoplasia p < 0.001). Subjects with normal thyrotropin (TSH) (>0.4 mU/L) at presentation had a nonsignificantly increased risk of thyroid neoplasia (p = 0.07) and malignancy, in contrast to those with low TSH (<0.4 mU/L). We confirmed FNAC of the thyroid to be an accurate test in the detection of thyroid neoplasia. Gender and goiter type at presentation both contribute significantly to the prediction of the diagnosis of thyroid neoplasia.

Parotid duct carcinoma arising in bilateral chronic sialadenitis

It is well recognized that, in general, chronic inflammation can predispose to malignant change. There is however, to our knowledge, no previously reported association between chronic obstructive sialadenitis and salivary gland epithelial malignancy. We describe here the first reported example in the English literature of a salivary duct carcinoma arising in a parotid gland with a long history of chronic obstructive sialadenitis. It is possible that a causal relationship exists between the two conditions. If this were the case then non-surgically treated chronic obstructive sialadenitis patients may well warrant careful clinical follow-up.

Reconstructive techniques currently used following resection of hypopharyngeal carcinoma

There is no general consensus as to the best method of reconstruction following total laryngopharyngectomy for hypopharyngeal carcinoma. The aim of this study is to attempt to establish the current practice amongst British ENT Consultants and to ascertain the reasons for their choice of reconstructive technique. An anonymous questionnaire was sent to 546 consultants in the UK and the results of 363 (66.5 per cent) were analysed. One hundred and twenty-eight (35.3 per cent) consultants replied that they performed surgery for hypopharyngeal carcinoma. Sixty-five (50.8 per cent) performed a stomach pull-up procedure, 23 (18 per cent) used a jejunal free flap, 36 (28.1 per cent) used both and four (3.1 per cent) used other techniques. In the stomach pull-up group, the main reasons given for their choice were because there was no lower resection margin (48 out of 65) and because of tradition in the way they were trained (37 out of 65). In the group using the jejunal free flap, lower morbidity (18 out of 23) and mortality (14 out of 23) were the main reasons for their choice. The questionnaire also found that amongst the 60 consultants who would consider using a jejunal free flap, the majority (39) aimed for a lower clearance margin of 2-4 cm, while 17 aimed for > 4 cm clearance. This study provides a good indication of the current practice in the UK of reconstruction following resection for hypopharyngeal carcinoma. It appears that the stomach pull-up remains the most commonly used method of reconstruction, but the jejunal free flap is becoming increasingly more popular because of its lower morbidity and mortality.

Dysphagia secondary to invasive candidiasis of a jejunal free flap

The presence of a mass in a jejunal free flap that causes dysphagia less than two years after a pharyngolaryngectomy for carcinoma usually indicates tumour recurrence. We present a case of invasive candidiasis of a jejunal free flap presenting with dysphagia and a mass. To our knowledge this is previously unreported. Such a cause should always be considered in the differential diagnosis, as early recognition and treatment are likely to result in a favourable outcome.

Fibroblast growth factors 1 and 2 and fibroblast growth factor receptor 1 are elevated in thyroid hyperplasia

We have previously reported increased expression of fibroblast growth factor (FGF-1 and FGF-2) in benign and malignant human thyroid neoplasia. To determine the role of these factors in thyroid hyperplasia we have examined their expression in multinodular goiter and compared findings with those in normal thyroid tissue. Because the effects of FGF-1 and FGF-2 are predominantly mediated through the FGF receptor-1 (FGFR-1), its expression has also been examined. Immunocytochemistry was performed on sections from multinodular goiters (n = 18) and normal thyroid (n = 7). Cytoplasmic staining for FGF-1, FGF-2, and FGFR-1 was scored on a scale of 0 (no staining) to 3 (heavy staining) and expressed as a percentage of total cells stained. Confocal microscopy of immunofluorescent staining for FGF-1, FGF-2, and FGFR-1 in sections of multinodular goiter (n = 3) and normal thyroid (n = 3) provided quantitation of immunostaining. FGF-1 expression was significantly increased in multinodular goiter when compared with normal. A mean of 74% of follicular cells in multinodular goiter compared with 9% of follicular cells in normal thyroid expressed FGF-1 (P < 0.0001). When expression of FGF-2 was examined, 77% of the follicular cells in multinodular goiter compared with 5% in normal thyroids were immunopositive (P < 0.0001). Confocal microscopy revealed that the intensity was 160 times greater in follicular cells in sections of multinodular goiters when compared with normal. When expression of FGFR-1 was analyzed, 89% of the follicular cells in multinodular goiter stained positively, compared with 15% of follicular cells in sections of normal thyroid. Confocal microscopy revealed a 6-fold increase in intensity of FGFR-1 expression in follicular cells of multinodular goiter (P < 0.05). In addition, there was significant nuclear expression of FGFR-1 in multinodular goiter contrasting with negligible expression in normal thyroid. These data show that enhanced expression of FGF-1, FGF-2, and FGFR-1 accompany thyroid hyperplasia and are not exclusively associated with the neoplastic state. These factors may be involved in the pathogenesis of uncontrolled thyroid growth observed in these conditions.

Papillary carcinoma arising in a thyroglossal duct cyst: a case report and literature review

Papillary carcinoma arising in a thyroglossal duct cyst is a rare finding. Less than 100 cases have been reported in the English literature. In most cases the diagnosis is only established after excision of a clinically benign thyroglossal duct cyst. The aetiology of such tumours is unclear but de novo origin and spread from a primary thyroid gland tumour has been suggested. This has important implications for therapeutic approaches. A further case of thyroglossal duct carcinoma is presented and the management is discussed on the basis of the current rationale for treatment of thyroid cancer.

Primary malignant melanoma of the pharynx

A case of primary malignant melanoma of the pharynx is presented. Mucosal melanomas of the upper respiratory tract are rare. They tend to present late and therefore the prognosis is generally poor. The initial mainstay of treatment is adequate surgical resection. Prognostic factors are less well documented than in cutaneous melanoma.

Metastatic squamous carcinoma in the neck: an anatomical and physiological study using CT and SPECT 99Tcm (V) DMSA

Technetium-99m (99Tcm) (V) dimercaptosuccinic acid (DMSA) is a new tumour imaging agent that has been used to image squamous cell carcinoma (SCC) of the head and neck. This study has been undertaken to compare clinical examination with computed tomography (CT) (anatomical) and SPECT 99Tcm (V) DMSA (physiological) imaging in the evaluation of metastatic SCC of the neck. Twenty-five patients with head and neck cancer were studied. Computed tomography was as sensitive but more accurate than clinical examination in predicting the presence of cancer. SPECT 99Tcm (V) DMSA was inferior to both techniques in identifying metastatic disease. There is no role for SPECT 99Tcm (V) DMSA imaging in the management of patients with SCC metastatic to the neck. Combined imaging with CT offered no advantages over anatomical imaging with CT alone. There is no role for CT in the routine evaluation of the clinically N0 neck and the role of CT of the neck in the management of patients with metastatic SCC is discussed.

Free flaps in head and neck reconstructive surgery: a review of 77 cases

Recent advances in surgical technique and instrumentation have ensured that success rates for microvascular free transfer can now exceed 90%. This paper reviews a prospective study of 77 free flaps performed at the Royal Marsden Hospital under the care of one surgeon (NMB) over a 2-year period. 76 patients who underwent 77 free flaps were studied. 68 patients had malignant tumours and 8 had benign lesions. The flap success rate was 95% and the mortality rate 0%. The major complication rate was 20% and the most common complication was a salivary fistula (12%). Microvascular free transfer to the head and neck is not associated with increased morbidity and mortality. It offers single stage, reliable, effective reconstruction using a wide variety of donor sites and tissues.

The pharmacokinetics and biodistribution of technetium-99m(V)dimercaptosuccinic acid in an animal tumor model

This study used an established rabbit tumor model with squamous carcinoma to evaluate the pharmacokinetics and biodistribution of technetium-99m-(V)dimercaptosuccinic acid. A total of 54 rabbits were studied (25 with no tumor; 29 with tumor). Technetium-99m(V)dimercaptosuccinic acid had a bi-exponential blood clearance in rabbits with no tumors (28 and 325 min) and in rabbits with tumors (27 and 352 min). There was no significant difference (p greater than 0.05) in mean clearance times between the two groups and clearance appeared unaffected by tumor mass. Technetium-99m(V)dimercaptosuccinic acid had a bi-exponential cumulative urine excretion with no apparent difference in half-times between non-tumor and tumor rabbit groups (200 and 240 min, respectively). Technetium-99m(V)dimercaptosuccinic acid had a major organ biodistribution in rabbits which included bone, kidneys, bladder and the blood pool. The major route of excretion was via the urine. There was no significant difference (p greater than 0.05) in organ biodistribution between rabbits with no tumors and rabbits with tumors and there was no evidence of active uptake of technetium-99m(V)dimercaptosuccinic acid by either squamous carcinoma or inflammatory tissue.

Synchronous primary mucosal melanoma and mucoepidermoid carcinoma of the maxillary antrum

We present a case of contiguous primary malignant melanoma of the nose and maxillary antrum and mucoepidermoid carcinoma of the maxillary antrum. We believe that this association has not been previously recorded; whether this represents divergent differentiation in a single tumour or 'collision' of two separate tumours is uncertain.

Metastatic carcinoma in the neck: a clinical, radiological, scintigraphic and pathological study

This study was undertaken to compare clinical evaluation of the neck with 99mTc(v) DMSA planar scintigraphy and computerized tomography (CT) in patients with head and neck carcinoma. Twenty-six patients were studied and in all but one the neck was previously untreated. A total of 31 neck dissections were performed and the specimens examined histopathologically. CT was approximately as accurate (71%) as clinical examination (68%) and more accurate than 99mTc(v) DMSA planar scintigraphy (48%) in predicting which necks contained metastatic carcinoma. Overall, 13% of necks had their staging correctly changed by 99mTc(v) DMSA scintigraphy compared with 10% for CT. Although scintigraphy upstaged 13% of clinically N0 necks compared to 6% for CT, it was less sensitive and specific than either clinical examination or CT. 99mTc(v) DMSA planar scintigraphy has no role to play in the investigation of patients with metastatic carcinoma to include the clinically N0 neck.

Experience in the surgical management of medullary thyroid carcinoma

The management of 12 patients with medullary thyroid carcinoma is reviewed. All patients underwent total thyroidectomy. Local nodal and extracapsular spread was aggressively resected, followed by radiotherapy. No patient died from uncontrolled local disease. Prolonged survival after radical treatment is demonstrated even in the presence of distant metastases.

Technetium-99m (v) dimercaptosuccinic acid: a clinical and scintigraphic study in an animal tumour model

Technetium-99m (99mTc) (v) dimercaptosuccinic acid (DMSA) is a new tumour-imaging agent which has been used to image head and neck squamous carcinoma. This study used an established rabbit tumour model to compare palpation versus planar scintigraphy in the detection of superficially transplanted cancers. Palpation detected 83% of tumours measuring less than 2 cm compared with 58% for scintigraphy. Overall, the sensitivity for palpation was 88% (77% specificity) compared with 50% (63% specificity) for scintigraphy.

The reliability of palpation in the assessment of tumours

There is now a joint UICC-AJC classification for cervical lymph nodes based mainly on the size of the nodes. There is a recognized error in palpation, not only for detecting the presence of tumour but also its size. This study used an animal tumour model system to compare the ability of 6 independent observers of varying experience to detect and stage superficially transplanted growths. A preclinical medical student was as good as a Consultant ENT Surgeon in predicting the presence of tumour but the ability to stage tumours accurately was related to experience. Whilst the most experienced observers accurately estimated the size of tumours less than 2 cm, they were less accurate for larger (greater than 2 cm) tumours which were constantly understaged. This phenomenon may have important clinical implications particularly related to current nodal staging criteria.