Complications of neck dissections in papillary thyroid carcinoma. A modified procedure to reduce parathyroid morbidity

Lymphatic metastasis develops in approximately 20% to 80% of patients with papillary thyroid carcinoma (PTC). Clinically evident pathologic nodes should be treated with therapeutic neck dissection. The extent of lymph node dissection, based on predictable drainage patterns from PTC, includes central compartment dissection with nodal clearance of level VI, and modified radical dissection of the lateral compartment with removal of levels II through V. Neck dissection, though a reliably safe procedure, carries certain potential complications.The most significant morbidity following therapeutic neck dissection for PTC is hypoparathyroidism, related to parathyroid damage leading to temporary or permanent hypocalcemia. This complication occurs most often when lateral neck dissection is combined with total thyroidectomy plus central neck dissection. That increased hypoparathyroidism appears not to be associated with incidental removal of the parathyroid glands or the number of parathyroid glands preserved, but to vascular compromise in the dissected central neck, related to the extension of nodal dissection to include the central neck to lateral cervical compartment. To reduce parathyroid morbidity we have modified the surgical procedure in the management of patients with PTC and neck nodal involvement, and approach, first, the lateral compartment via extrathyroideal space and perform the nodal basins dissection according to operation popularized by O.Suarez and named " functional neck dissection", which is based on the facial compartments and the facial envelope in the neck. KEY WORDS: Cervical lymph node metastases, Neck dissections, Papillary thyroid carcinoma.

Comparison of Chromosome Aberration Frequency before and after Administration of 131I in Two Groups of Thyroid Cancer Patients

The chromosome aberration frequencies of 10 thyroid cancer patients, before and after their first radioiodine treatment (group A), were compared to the frequencies found in another 10 subjects previously treated with two or more radioiodine administrations (group B). Our data show that the relative increase in chromosome-type aberrations was similar in the two groups: from 2.0% to 3.7% (group A) and from 4.7% to 9.0% (group B). However, the increase in the number of cells with aberrations was greater in group A. Moreover, the higher frequency of aberrations in group B, even before the radioiodine treatment, points out the effect of previous treatments and demonstrates the persistence of this type of lesion. The sister chromatid exchange frequency in the two groups was also analysed, but no effect bound to the radioiodine treatment could be demonstrated.

Complications of Neck Dissections in Papillary Thyroid Carcinoma: A Modified Procedure to Reduce Parathyroid Morbidity

BACKGROUND/AIM

Hypoparathyroidism is the most significant morbidity after neck dissection for thyroid cancer. Addition of lateral neck dissection (ND) to central ND combined with total thyroidectomy (TT) increases the risk of postoperative hypoparathyroidism compared to TT plus central ND. The aim of this study was to verify if a modified procedure and different access to the neck for lateral ND may improve safety.

PATIENTS AND METHODS

In 62 patients with papillary thyroid cancer (PTC) undergoing TT plus central and lateral ND between 2010 and 2013, lateral ND was performed as first step approaching the neck via extrathyroideal space. Calcium in serum and parathormone (PTH) were determined preoperatively, intraoperatively and during the follow-up.

RESULTS

Twenty patients (32%) developed postoperative hypocalcemia. Calcium levels and PTH completely recovered for 58 out of 62 patients from 3 to 6 months after surgery. After a mean of 12 months' follow-up, only four patients (6.5%) had developed permanent hypoparathyroidism. The incidence of parathyroid complication after TT plus central ND and lateral ND did not differ from postoperative hypoparathyroidim after TT plus central ND.

CONCLUSION

The presented surgical procedure may provide a better outcome in terms of parathyroid morbidity.

Papillary thyroid microcarcinoma: proposal of treatment based on histological prognostic factors evaluation

BACKGROUND

Papillary thyroid cancer accounts for approximately 80% of thyroid tumors and its incidence has increased over the past decades. Papillary thyroid microcarcinomas (PMCs), defined by the World Health Organization as less than 1.0 cm in size, are identified with greater frequency. The majority of patients with PMCs follows a benign clinical course, however a subgroup of these carcinomas is as aggressive as bigger tumors. Risk factors related with poor outcome have not been defined and the optimal treatment has not been proved. The authors investigated histologic prognostic factors predicting high risk patients considered for more aggressive treatment and propose reviewed therapeutic guidelines based on analysis of histopathologic features which determined the recurrence rate.

STUDY DESIGN

One hundred forty nine patients with PMC who underwent surgery were retrospectively analyzed. Clinical and histopathologic parameters potentially predicting patient outcome and recurrent disease were statistically investigated, after a minimum follow-up of 5 years.

RESULTS

After a median follow-up of 5.4 years 28 of 149 patients experienced recurrent disease. All of them were reoperated on and newly treated with radioiodine administration. The multivariate statistical analysis identified extrathyroidal invasion (Odds Ratio, OR, 58.54; P=0.013), the solid pattern (OR,25.77; P>0.001), the tumor multifocality (OR, 15.80; P= 0.005), and the absence of tumor capsule (OR, 9.74; P=0.015) as significant and indipendent risk factors for the appearance of PMCs recurrences. Of note, none of the PMC "incidentally" discovered at histopathological examination alone experienced recurrent disease during follow-up.

CONCLUSIONS

Although most PMC have favourable long-term prognosis, some patients (19% in our series) presented aggressive clinical course strongly correlated with some histopathologic features (extrathyroidal invasion, tumor multifocality, solid pattern and absence of capsule) who need to be investigated and for whom a radical therapeutic approach is recommended based on total thyroidectomy and regional lymphadenectomy followed by radioiodine administration.

Radioguided parathyroidectomy in forearm graft for recurrent hyperparathyroidism

We report a peculiar case of recurrent hyperparathyroidism caused by hyperplasia of a forearm graft implanted following a total parathyroidectomy in a 38-year-old patient with chronic renal failure. The forearm graft hyperplasia was detected using (99)Tc(m)-sestamibi scanning, which identified hyperplastic transplanted parathyroid tissue in the forearm of the patient. During the initial surgery, the surgeon failed to mark the parathyroid tissue with sutures or clips to facilitate locating it. Therefore, we referred the patient for radioguided surgery. This surgical procedure allowed us to locate and completely remove the hyperfunctioning transplanted parathyroid tissue.

Immunohistochemical evaluation of inflammatory and proliferative markers in adjacent normal thyroid tissue in patients undergoing total thyroidectomy: results of a preliminary study

Background

Total thyroidectomy is the treatment of choice in the majority of thyroid malignancies, preventing the risk of reoperative surgery due to recurrences. In order to assess the usefulness of such an approach, expression levels of inflammatory and proliferative markers were evaluated immunohistochemically in non-lesional adjacent thyroid tissues from a group of patients who underwent total thyroidectomy for different thyroid diseases.

Methods

Nineteen consecutive patients treated by total thyroidectomy for different thyroid diseases entered the study. IL-6Rb gp130 component of the IL-6 cytokine family members receptor complexes, STAT3 cytokine signalling transduction and transcription activation factor, p53 as tumour suppressor and CK19 cytokeratin as proliferation marker were analyzed in non-lesional thyroid tissues.

Results

Gp 130 expression was detected in all tissue samples with a scattered distribution while STAT3 and p53 positivity was observed in 17 out of 19 patients with a prevailing cytoplasmic localization. Cytokeratin 19 positivity was found in patients with papillary carcinoma, in one case of follicular adenoma, 3 multinodular goiters and one Basedow disease.

Conclusion

Based on the results of this preliminary study, it may be concluded that the presence of a persisting cytokine-mediated activation associated with cytoplasmic localization of p53 is frequently observed in different thyroid diseases. Such a process seems to occur in the thyroid gland as a whole. Moreover, STAT3 activation as well as mutant p53 are risk factors for the development of neoplastic diseases. Total thyroidectomy may be supported as an adequate therapeutic approach for all the patients in whom overexpression of cytokine-dependent markers is detected.

Thyroidectomy with ultrasonic dissector: a multicentric experience

INTRODUCTION

We have conducted a clinical controlled trial (CCT) on patients who had undergone thyroidectomy for goitre or thyroid carcinoma. The endpoint of this study was to evaluate the benefits of ultrasonic dissector vs conventional technique (vessel ligation and tight) in patients undergoing thyroid surgery.

PATIENT AND METHODS

Between January 2007 and December 2009 a CCT was conducted on 2.736 consecutive patients admitted to our clinical wards, who had undergone thyroidectomy for goitre or thyroid carcinoma. They were divided in two group: 1.021 patients (203 male and 818 female) underwent thyroidectomy with ultrasonic dissector (UAS) and 1.715 patients (369 male and 1.346 female) underwent throidectomy with conventional technique (vessel ligation and tight) (CT).

RESULTS

The operative time (UAS 80 minutes mean, 50 to 120 min., vs CT 120 minutes, 70 to 180 minutes) was much lower in the thryoidectomy with UAS group. The incidence of transient laryngeal nerve palsy (UAS 17/1.021 patients. 1.6% vs CT 16/1.715 patients, 0.9%) was higher in the thyroidectomy with UAS group; the incidence of permanent laryngeal nerve palsy was similar in two groups(UAS group; there are no relevant difference in the incidence of permanent hypocalcemia (UAS 26/1.021 patients, 2.5% vs 35/1.715 patients, 2%) which was similar in two groups. Also the average post-operative hospitalization was similar in two groups (2 days).

CONCLUSIONS

Actually, the only significant advantage shown from this CCT is represented in terms of cost-effectiveness (reduction of the usage of operating room and hospitalization) for patients treated with UAS, subsequent to the significant reduction of operative duration. Although the analysis showed that the patients who were treated with ultrasonic dissection don't present more favourable results in incidence of post-operative transient complication:transient laryngeal nerve palsy (1.6% in UAS vs 0.9% in CT) and transient hypocalcaemia (9.5% in UAS vs 7.7% in CT). There is no significant difference in the incidence of permanent laryngeal nerve palsy (0.9% in UAS vs in 1% CT). The experience of surgeon is the only important factor which can influence the appearance of these complications; the usage of Ultrasonic dissector can only help surgical action but can't repair the experience of the operator.

The role of fine-needle aspiration performed with liquid-based cytology in the surgical management of thyroid lesions

BACKGROUND

The aim of this retrospective study was to assess the accuracy and usefulness of cytological classification of fine-needle aspirates in determining the appropriate surgical treatment for thyroid lesions studied with conventional smears (CS) and liquid-based cytology (LBC) in a split-sample method.

PATIENTS AND METHODS

A total of 353 patients were studied with both CS and LBC. The cytological diagnoses were classified according to the British Thyroid Association into 5 groups: Thy1, inadequate; Thy2, non-neoplastic or benign group including goiter, thyrocytic hyperplasia without nuclear atypia and thyroiditis; Thy3 or indeterminate/follicular proliferation, including follicular neoplasm not otherwise specified and oxyphilic follicular neoplasm; Thy4, suspicious for malignancy, including follicular lesion with nuclear pleomorphism; Thy5, diagnostic for malignancy including papillary carcinoma and medullary carcinoma. The efficacy of thyroid fine-needle aspiration processed by CS with LBC in a split-sample method was evaluated.

RESULTS

Overall 164 patients were included in the Thy2, 97 in the Thy3, 49 in the Thy4, and 43 in the malignant Thy5 group. The percentage of unnecessary thyroidectomies decreased from 58.5 to 42% in our series.

CONCLUSION

Our subclassification, according to the British Thyroid Association classification, attempts to reduce the number of Thy3 who undergo surgery. The comparison between the traditional management of thyroid lesions and our morphological categories with the use of CS and LBC together allows the number of unnecessary thyroidectomies to be reduced.

[Diagnostic, therapeutic and healthcare management protocols in parathyroid surgery. 1st Consensus Conference]

AIM

The aim of the study was to draw up a management protocol in parathyroid surgery promoted by the Italian Association of Endocrine Surgery Units (UEC Club), based on the guidelines of the main international scientific societies and shared by the experts and applied by the operators in the sector.

METHODS AND CONSENSUS

The management protocols, already presented in 2003, on the occasion of the current review were examined by the 1st Consensus Conference called on the topic by the Italian Association of Endocrine Surgery Units (UEC). The Conference comprised two distinct sessions, the first in November 2006 within the framework of the 5th National Congress of the UEC Club in Verona, and the second in September 2007 within the framework of the 10th Multidisciplinary Scanno Prize Meeting. A selected board of endocrinologists and endocrine surgeons examined the individual chapters and submitted the consensus text for the approval of several experts.

CONCLUSIONS

The diagnostic, therapeutic and healthcare management protocols in parathyroid surgery approved by the 1st Consensus Conference are officially those proposed by the Italian Association of Endocrine Surgery Units (UEC Club) and are subject to review by October, 2009.

Iodine-131 radio-guided surgery in differentiated thyroid cancer: Outcome on 31 patients and review of the literature

In the present study we investigated the role of radio-guided surgery with Iodine-131 (I-131) in a group of 31 patients with differentiated thyroid cancer (DTC) and loco-regional recurrent disease. The principal inclusion criterion for I-131 radio-guided surgery in our protocol was the presence of an I-131 positive loco-regional disease relapse after previous total thyroidectomy and at least 2 ineffective conventional I-131 treatments. The protocol we used consisted of the following steps. Day 0: all patients were hospitalized and received a therapeutic 3.7 GBq (100 mCi) dose of I-131 after thyroid hormone therapy withdrawal in condition of overt hypothyroidism (serum TSH levels>30 microUI/ml). Day 3: a whole body scan following the therapeutic I-131 dose (TxWBS) administration was acquired. Day 5: neck surgery was performed through a wide bilateral neck exploration using a 15-mm collimated gamma probe, measuring the absolute intra-operative counts and calculating the lesion to background (L/B) ratio. Day 7: post-surgery TxWBS was performed using the remaining radioactivity to evaluate the completeness of tumoral lesions extirpation. The final histologic examination showed the presence of 184 metastatic foci; among them, 98 (53.2%) were evident by both TxWBS and gamma probe evaluation, 76 (41.3%) were demonstrated only by gamma probe, and 10 (5.4%) were negative by both TxWBS and gamma probe evaluation. During follow-up (8 months to 4.9 years, mean 2.8 years), DxWBS, serum Tg levels off l-T4, and US showed absence of loco-regional disease in 25 patients (80.6%) while 6 patients had persistent disease. In conclusion, this protocol allowed us to identify neoplastic foci with high sensitivity and specificity, enabling us to remove loco-regional I-131 disease recurrences resistant to previous conventional I-131 therapies. Furthermore, the gamma probe allowed detection of some additional tumoral foci in sclerotic areas or located behind vascular structures that were not visualized at the pre-surgery TxWBS evaluation.

Evaluation of the surgical completeness after total thyroidectomy for differentiated thyroid carcinoma

BACKGROUND

To quantify the rate of patients without thyroid remnants, to identify predictive factors for the absence of residual thyroid tissue and to evaluate number, site, size and function of thyroid remnants after total thyroidectomy for differentiated thyroid carcinoma (DTC).

METHODS

Thousand one hundred and seventy-eight patients who underwent total thyroidectomy for DTC were evaluated; 343 patients with lymph node or distant metastases and 115 patients with detectable thyroglobulin autoantibodies (TgAb) were excluded. (131)I ablative treatment (RAI) without preliminary diagnostic (131)I whole body scans (DxWBS), and 24-h (131)I quantitative neck uptake (RAIU test) and thyroglobulin (Tg) off L-T4 evaluation were performed in the remaining 720 pts. In 252 patients a 99mTc-pertechnetate pre-operative thyroid scan (99mTc-scan) was used for comparison with (131)I neck scans after RAI to evaluate site of thyroid remnants. Only patients with thyroid remnants were evaluated for successful ablation 6-10 months after RAI.

RESULTS

Post-treatment whole body scan (TxWBS) demonstrated lack of thyroid remnants in 50/720 patients and the best predictive factors for the absence of residual thyroid tissue were RAIU <1% and undetectable Tg off L-T4. Thyroid remnants were present in 670/720 patients. In 252 patients with (99m)Tc-scan, 617 sites of functioning thyroid tissue were found: 381 within and 236 outside the thyroid bed. Complete successful ablation was achieved in 610/670 patients with thyroid remnants.

CONCLUSIONS

This study confirms that most patients (93.1%) have thyroid remnant after total thyroidectomy for DTC. Most thyroid remnants were contralateral to tumour site and were even observed outside thyroid bed. However, a real total thyroidectomy, demonstrated by negative TxWBS, RAIU <1% and undetectable Tg off L-T4, was achieved in 6.9% of patients.

[Diagnostic, therapeutic and healtcare management protocols in thyroid surgery. I consensus conference (UEC club)]

The aim of the study was to draw up a management protocol in thyroid surgery promoted by the Italian Association of Endocrine Surgery Units (Club delle UEC), shared by the experts and applied by the operators in the sector. The management protocols already presented in February 2002 and drawn up by the first Author of the present publication on the occasion of the current review were examined by the I Consensus Conference called on the topic by the Italian Endocrine Surgery Units. The conference comprised two distinct sessions, the first on 18 June 2005 within the framework of the 4th National Congress of the Club delle UEC in Naples, and the second on 17 September 2005 within the framework of the 8th Multidisciplinary Scanno Prize Meeting. A selected board of endocrinologists and endocrine surgeons, chaired by Aldo Pinchera and comprising the first nine Authors of this paper, examined the individual chapters in close collaboration with the other Authors, comparing their findings with the opinions of the experts cited in the text and submitting the consensus text for the approval of all those present. The diagnostic, therapeutic and healtcare management protocols in thyroid surgery approved by the I Consensus Conference are officially those proposed by the Italian Association of Endocrine Surgery Units (Club delle UEC) and are subject to review by October 1, 2007.

Treatment of local and regional recurrences of differentiated thyroid cancer by radio-guided surgery with iodine-131

BACKGROUND/MATERIAL AND METHODS: The aim of this study was to assess the reliability of radioiodine ((131)I) and a gamma probe for radio-guided surgery (RGS) to detect and radically dissect lymph node recurrence (LNR) in 15 patients with differentiated thyroid cancer (DTC). The major inclusion criterion was the presence of a radioiodine-positive LNR after previous total thyroidectomy and at least two ineffective (131)I treatments. The protocol was designed as follows: Day 0--all patients were hospitalized and received 3.7 GBq of (131) I while clinically hypothyroid. Day 3--pre-surgery whole-body scan with a therapeutic (131)I dose (TxWBS) was acquired. Day 5--neck surgery using a gamma probe (Navigator GPS, AutoSuture, Italy), recording the absolute counts and the lesion/background (L/B) counts ratio was performed. Day 7--post-surgery TxWBS was performed using the remaining radioactivity.

RESULTS AND CONCLUSIONS

This protocol permitted us to identify neoplastic foci with high sensitivity and specificity, enabling us to remove lymph node metastases resistant to radioiodine therapy in a single session. The protocol also allowed detection of some additional tumoural foci in sclerotic areas or behind vascular structures that were not seen at the pre-surgery TxWBS evaluation.

A less invasive, selective, functional neck dissection for papillary thyroid carcinoma

HYPOTHESIS

To describe an alternative lateral neck access in order to perform neck dissection in papillary thyroid carcinoma (PTC) with lymph node involvement.

DESIGN

Prospective (January 2000 to December 2003), 36-month study.

SETTING

Catholic University of Rome and University of "Tor Vergata", Rome, Italy.

PATIENTS AND METHODS

Twenty-four consecutive patients with PTC and cervical lymph node metastases were included. Functional neck dissection (FND), unilateral or bilateral, was performed acceding via a lateral dissection through a traditional Kocher incision, running along the superficial fascia of the neck and posteriorly to the sternocleidomastoideus muscle.

RESULTS

Mean age was 39.04+/-13.69 years. Twenty patients were women and four were men. Mean tumour size was 2.5+/-1 cm, while the greatest metastatic lymph node size was 4.5 cm. Minimally invasive, selective FND was performed in all patients associated to total thyroidectomy and central compartment lymph node clearance. Metastatic lymph nodes were found in 142 out of 340 of the lymph nodes dissected.

CONCLUSIONS

Minimally invasive neck dissection seems to carry a lower risk in terms of specific morbidity and allows a quicker recovery and a better aesthetic result. This access has to be considered as a less invasive procedure compared to the other surgical accesses for the radical or modified lateral neck dissection.

[Differentiated tumor of the thyroid in children and adolescents]

Differentiated thyroid carcinoma (DTC) is rare in young patients and represents 0,5 to 3,0% of childhood carcinomas. The incidence increases with age: a peak incidence is observed between 15 and 19 years of age. DTC in children is frequently associated with greater risk of cervical lymph node involvement (60-80% of cases) and lung metastases at diagnosis in 20% of patients. However the prognosis for these patients is better when compared with that of adults, despite a high incidence of relapse, leading to reoperation. Young age (<16 years), lymph node involvement or distant metastases at diagnosis and some histopathologic characteristics have been suggested as predictive factors of recurrences. The records of 33 patients with DTC in a 14-year period (1990-2004) were reviewed. There were 31 females and 2 males who ranged from 11 to 21 years. At the diagnosis 15 patients had disease confined to the thyroid, 18 had additional lymph node metastases in the neck; one of them had also lung metastases. Total thyroidectomy (TT) was the elective approach in all patients (4 cases videoassisted). TT was associated to functional neck dissection in 21 cases. 131I was administrated to 28 patients (3,7 GBq as ablative dose): 11 of this received further radioiodine treatments (mean 7,4 GBq) because of elevated serum thyroglobulin levels and presence of loco-regional or lung metastasis at diagnostic total body scan after 131I treatment. The overall survival rate was 100% at a follow up of 4 months to 14 years.

[Legal contentions in thyroid surgery. Kind of preoperative information to the patients]

The question of patients information and the achievement of an informed consent to medical and/or surgical treatment by the patient still represents one of the main issue of the medical profession, having greater importance nowadays in respect to the past regarding the relationship doctor-patient and to the diagnostic-therapeutic approach to the patient. Written informed consent is a pre requisite for surgical intervention as it provides the forum for the patient to appreciate implications of the procedure and the doctor to explain details and effects of the surgery. Patients refusal is, nowadays, according to the latest orientation of the Italian Supreme Court, the major limitation to medical or surgical intervention. For these reason we have thought better to propose a written form of informed consent regarding the thyroid surgery, which implies, more than other surgery's act, the exposition of the patient to adverse iatrogenic risks and as a consequence it can expose the surgeon to criminal or civil liabilities.

Diagnostic Lobectomy for Unilateral Follicular Nodules of the Thyroid Gland

We describe our technique of diagnostic lobectomy (DL) and the rationale it is based on. We define DL as a minimally invasive procedure consisting of total lobectomy and isthmusectomy, with preservation of the omolateral recurrent laryngeal nerve and parathyroid glands, but without digital exploration of the contralateral lobe. The fact that re-entry into the previously explored field to complete thyroidectomy increases the risk of complications must be taken into consideration. The subjects were 63 consecutive patients who underwent surgery for unilobar follicular neoplasms of the thyroid gland between January 1997 and December 2002. There were 49 follicular adenomas and 14 carcinomas. In the 14 patients with thyroid cancer, total thyroidectomy was performed within 2 weeks after the first operation in a sterile environment with normal anatomical cleavage plains, avoiding any risk of injury to the laryngeal nerves and parathyroid glands. It is concluded that DL is a safe and suitable surgical procedure for patients with follicular-structured lesions of the thyroid gland.

In vivo and in vitro effects of different anaesthetics on platelet function

Different effects of thiopental, propofol and sevoflurane on platelets have been reported. Patients undergoing thyroid surgery were anaesthetized with thiopental-fentanyl-sevoflurane (n = 11) or propofol-fentanyl-sevoflurane (n = 9). Platelet aggregation and thromboxane A2 generation were studied at baseline, and at the end of anaesthesia induction and surgery. Dose-response experiments were also performed in vitro with single agents. Thiopental-fentanyl-sevoflurane significantly reduced collagen-induced aggregation by the end of induction, while ADP-induced aggregation and thromboxane generation were unaffected. Propofol-fentanyl-sevoflurane had no effect on platelets. Thiopental dose-dependently inhibited platelets in vitro, while fentanyl or propofol did not. In conclusion, thiopental reduces platelet function both ex vivo and in vitro and propofol might be considered haemostatically safer.

Revisited anatomy of the recurrent laryngeal nerves

BACKGROUND

The most frequent postthyroidectomy complication is recurrent laryngeal nerve (RLN) damage with subsequent vocal cord palsy.

METHODS

We have undertaken an intraoperative study aimed to determine the course, distribution, and RLN's anatomical relationships with adjacent structures. Only its identification and its careful exposure allow prevention of iatrogenic injuries.

RESULTS

The RLN was always routinely exposed and identified in 1,543 thyroidectomies. All patients underwent laryngoscopic evaluation before surgery and at the time of discharge. A total of 2,626 RLN were observed. The number of nerves exposed to risk was 673 (25.6%). In the whole series, of 2626 nerves controlled, there were 11 (0.4%) permanent palsies.

CONCLUSIONS

Our study confirms that damage to the RLN or to one of its branches may be avoided only by identification and careful exposure of the nerve itself. An experienced surgeon with good knowledge of the anatomy of the RLN and its anatomical variations is required for uncomplicated treatment of thyroid disease.

Modified radical neck dissection via extra-thyroideal space (MRND vets) in papillary thyroid carcinoma

The purpose of this study was to describe an alternative lateral neck access to perform lymph nodes sampling and/or neck dissection via extra-thyroideal space (MRND vets) in papillary thyroid carcinoma with lymph nodes involvment. Twenty-four consecutive patients with papillary thyroid carcinoma were included. Lymph nodes sampling and modified radical neck dissection, unilateral or bilateral, were performed acceding via a lateral dissection through a traditional Kocher incision, running along the medial fascia of the neck, posteriorly to the sterno-cleido-mastoideus muscle (SCM). Mean age was 39.04 +/- 13.69 years. Twenty patients were women, and 4 were men. Mean tumor size was 2.5 +/- 1 cm.. Total thyroidectomy with lymph nodes dissection of the central compartment associated to modified radical neck dissection was performed in 17 patients: among these, nine patients had a preoperative diagnosis of the latero-cervical lymph nodes metastases, and eight had a perioperative diagnosis of metastases of the extensive sampling of the lower third of the jugular chain. Metastatic lymph nodes were found in 107 out of 615 lymph nodes dissected. The MNRD vets access for modified lateral neck dissection seems to carry a lower risk in terms of specific morbility and allows a quicker recovery and a better cosmetic result. This access has to be considered as a less invasive procedure compared to other surgical accesses for the radical modified lateral neck dissection.

Radio-guided surgery for lymph node recurrences of differentiated thyroid cancer

The objectives of this study were to assess the reliability of radio-iodine (131I) and a gamma probe for radio-guided surgery (RGS) to detect and then radically dissect lymph node recurrences (LNRs) in 10 patients with differentiated thyroid cancer (DTC). The major inclusion criterion was the presence of an iodine-positive LNR after previous total thyroidectomy and at least two ineffective 131I treatments. The protocol was designed as follows. Day 0: all patients were hospitalized and received 3.7 GBq of 131I in the hypothyroid condition. Day 3: presurgery whole-body scan with a therapeutic dose (TxWBS). Day 5: neck surgery using a gamma probe (Navigator GPS, AutoSuture, Italy), recording the absolute counts and the lesion/background (L/B) counts ratio. Day 7: post-surgery TxWBS performed using the remaining radioactivity. The presurgery TxWBS was positive in all patients, and the post-surgery TxWBS showed a negative pattern in 7 of 10 patients, suggesting the efficacy of the surgical procedure in most of the patients. After RGS the mean decrease in the absolute counts and the L/B counts ratio were 77.6% (52.7% minimum, 94.6% maximum) and 77.4% (52.3% minimum, 94.8% maximum), respectively. After operation the surgeon judged the procedure to be decisive in two patients, favorable in six, and irrelevant in two. The final histologic examination showed the presence of 78 lymph node metastases (mean of 8 per patient). There were 33 neoplastic lesions found by both TxWBS and gamma probe evaluations; 41 were shown only by gamma probe, and 4 were negative by both TxWBS and gamma probe evaluations. This protocol permitted us to look for neoplastic foci with high sensitivity and specificity, and we were able to remove lymph node metastases resistant to radioiodine therapy at a single session. The protocol also allowed detection of some additional tumoral foci in sclerotic areas or behind vascular structures that are difficult to identify and were not seen at the presurgery TxWBS evaluation. However, because of the possible false-negative results, complete excision must be undertaken in high risk patients with a local recurrence to eradicate the largest number of lymph nodes, independent of the counts measured by the gamma probe.

Coexistence of a parathyroid adenoma and parathyroid cyst causing primary hyperparathyroidism

The association of a functional parathyroid cyst with a parathyroid adenoma is an uncommon finding. In this report we describe the clinical history of a 60-yr-old man, presenting with the following findings: hypercalcemia (18.9 mg/dl), elevated serum parathormone levels (1320 pg/dl), hypercalciuria (228 mg/dl), and hyperphosphaturia (155 mg/dl). Neck ultrasound, magnetic resonance imaging (MRI) and 99Tc Sestamibi scintigraphy led to the identification of a left parathyroid adenoma, located at the lower pole of the left thyroid gland lobe, associated with a parathyroid cyst, located at the upper extremity of the same thyroid lobe. Parathyroidectomy was performed and the histological examination confirmed the diagnosis of a parathyroid adenoma with aspects of cystic degeneration and an upper parathyroid cyst. Analysis of the crystal clear intracystic fluid showed elevated parathyroid hormone (PTH) levels (137.000 pg/ml). The patient is normocalcemic at 2 yr after surgery without signs of recurrent parathyroid enlargements. Aetiology, diagnosis and management of parathyroid cyst will be discussed.

Follicular adenoma of the thyroid gland with extensive bone metaplasia

Follicular adenomas of the thyroid account for over 90% of benign neoplasms of the gland. They exhibit a wide range of morphological structures, from the classical follicular pattern to the peculiar hyalinizing trabecular pattern. Although follicular adenomas grow slowly, they are nonetheless subject to degenerative, most often hemorrhagic changes in their central portion. These hemorrhagic areas undergo further regressive changes such as sclerosis and calcification. However, the detection of a true bone formation with a trabecular structure and the presence of marrow is a very rare occurrence. A follicular adenoma with central cartilaginous metaplasia has been reported in literature but, to our knowledge, a follicular adenoma with bone metaplasia has never been described.

Thyroid tumors in children and adolescents: preoperative study

Several studies indicate that in young patients (less than 21 years of age at the time of diagnosis), the prognosis of thyroid carcinoma (TC) is more favorable than in older patients. However, a more radical treatment approach is recommended in children and adolescents due to the higher prevalence of local lymph-node involvement in these cases. Since the extent of primary surgical treatment is closely related to the overall prognosis, preoperative diagnosis becomes essential in the management of thyroid neoplasms in young patients. In this retrospective study (1987-1998), we analyzed a surgical series of 50 children and adolescents with thyroid nodules in an attempt to establish the role of diagnostic studies in detecting malignant lesions prior to surgery. Our diagnostic protocol for evaluating thyroid nodules was based on clinical evaluation, measurement of thyroid-hormone and thyroglobulin (TG) levels, anti-TG and anti-TPO antibody titers, calcitonin, CEA, and TPA levels, sonography, scintigraphy, and fine-needle aspiration cytology (FNAC) of the thyroid nodules and any enlarged lymph nodes. Eleven of the 15 cases of histologically confirmed carcinoma were preoperatively identified as malignant lesions with the aid of FNAC. The authors conclude that the preoperative work-up of children and adolescents with thyroid nodules requires the collaboration of an experienced team of professionals, and recommend FNAC as the initial test.

[Role of Doppler color ultrasonography in the diagnosis of thyroid carcinoma]

The aim of this study is to assess the efficacy and accuracy of color flow-Doppler sonography (CFDS) in predicting the malignancy of thyroid nodules. Seventy eight consecutive patients (52 females and 26 males), with 78 thyroid nodules (29 single nodules and 49 in a nodular goiter) have been examined by CFDS, before surgery, evaluating the hypoechogenicity of the nodule, the presence of microcalcifications and the halo sign absent and the vascular pattern, which has been classified as follows: absence of blood flow (type I), perinodular blood flow (type II), intranodular, with or without perinodular blood flow (type III), which is considered the most typical pattern of malignancy. On histology 22 nodules as carcinoma (CA) and 56 as benign nodules (BN) have been diagnosed. The most predictive for malignancy, sonographic pattern, "microcalcifications", has been found in 13/22 CA and in 4/56 BN (P < 0.0001, specificity 93%, sensitivity 59%); "hypoechogenicity" in 16/22 CA and in 8/56 BN (P < 0.0001, specificity 86%, sensitivity 73%), "absent halo sign" in 18/22 CA and in 16/56 BN (P < 0.0001, specificity 71%, sensitivity 82%.) have been found. On CFD type III pattern has been detected in 17/22 CA and in 24/56 BN (P < 0.15, specificity 57%, sensitivity 77%); type IIIa pattern (intranodular without perinodular blood flow) has been the most predictive for malignancy (P < 0.0001, specificity 100%, sensitivity 36%). The combination of type III pattern with "hypoechogenicity" in 13/22 CA and in 2/56 BN (p < 0.0001, specificity 93%, sensitivity 59%) has been found, with "absent halo sign" in 15/22 CA and in 3/56 BN (P < 0.0001, specificity 94.6%, sensitivity 68%), has been found, with "microcalcification" in 10/22 CA and in 0/56 BN (P < 0.0001, specificity 100%, sensitivity 45%) has been found. The combination of "microcalcifications" and absent halo sign" with type III pattern has been the most specific for malignancy, being detected in 11/22 Ca and 2/56 BN (P < 0.0001, specificity 96%, sensitivity 50%). In conclusion our results suggest that CFDS has an useful role in the assessment of thyroid nodules and it may provide information highly predictive for malignancy, above all when multiple, sonographic and vascular patterns are contemporaneously present in a thyroid nodule.

[Papillary microcarcinoma [correction of carcinoma] of the thyroid: clinical experience and prognosis factors]

Thyroid neoplasm of less than 10 mm in the largest diameter are defined as minimal thyroid cancer (MTC). These tumors are a common incidental finding at autopsy and in thyroid glands excised for other pathology. These tumors can metastasize and can cause significant morbidity and mortality. Clinical significance and optimal operative procedures of these lesions are still questioned. We studied 35 MTC in order to identify clinical and histologic characteristics as prognostic factors and to establish therapeutic management strategies. From January 1988 to December 1998, 177 patients with a primary thyroid cancer underwent surgery in the Department of endocrine-surgery of Catholic University in Rome: 35 of them (19.7%) had a MTC. In the post-operative follow-up 13 of the patients with MTC had a lymph node recurrency and/or distant metastases. Careful histologic examination showed multifocality in 12 patients, capsular infiltration in 10 patients and a solid tumor in 9 patients. MTC are common and they are associated with a good prognosis. Our multifactorial analysis has identified as important risk factors: capsular infiltration, solid lesion and multifocal disease. In these cases total thyroidectomy is mandatory.

Chromosomal aberrations, sister chromatid exchanges and high frequency cells in young patients with neurofibromatosis 1 (NF1)

Chromosomal aberrations (CAs), sister chromatid exchanges (SCEs) and high frequency cells (HFCs) have been assessed in peripheral blood lymphocytes of 10 neurofibromatosis (NF1) patients and 10 healthy controls. In both groups, the spontaneous rates and the induced (bleomycin for CA and MMC for SCE) frequencies were analyzed. No differences between cells from NF1 patients and controls were observed with respect to spontaneous or bleomycin induced CA. Spontaneous or MMC induced SCE frequencies were also similar in NF1 patients and controls. HFCs, on the contrary, were statistically lower in NF1 patients.

Surgery of differentiated thyroid carcinoma, lymph node metastases and locoregional recurrence

Surgery of differentiated thyroid carcinoma is burdened with risk factors that significantly impact on prognosis, as age at diagnosis and tumor stage. Problems involved concern the extent of surgical resection and the indication for regional lymphadenectomy. As for the former, the most popular approach is total thyroidectomy "on principle" with neck lymphadenectomy. Lobectomy may represent an alternative to total thyroidectomy in low risk patients with unifocal papillary carcinoma 1 cm or less in size, or minimally invasive follicular carcinoma. As for lymphadenectomy, most authors do not agree with surgery "on principle" but rather "of necessity", that is, in presence of clinically evident lymphadenopathy and neck lymphadenectomy is the preferred surgical strategy. In most cases surgery is the treatment of choice of locoregional recurrence. Careful preoperative work-up and accurate surgical procedure are mandatory.

Cystic Medullary Thyroid Carcinoma: Report of a Case with Morphological and Clinical Correlations

Cystic lesions of the thyroid are common findings. Although many thyroid cysts are of benign, some cases of hemorrhagic degenerative changes occur in neoplastic nodules, mostly follicular neoplasms and papillary carcinomas. The occurrence of hemorrhagic changes in medullary carcinomas has never been documented with aspirative cytological and histological pictures to the best of our knowledge. A case of medullary thyroid carcinoma with a large central hemorrhagic cyst is described, and the literature regarding the pathogenesis of this regression and the occurrence of cystic neoplasms in the thyroid is reviewed.

MFASAT: a new alphoid DNA sequence isolated from Macaca fascicularis (Cercopithecidae, Primates)

A new highly repeated DNA fragment isolated from Macaca fascicularis (MFASAT) is described. Our findings obtained by sequencing, Southern blot analysis, and fluorescent in situ hybridization (FISH) on metaphasic chromosomes strongly suggest that MFASAT can be considered as a member of the alphoid DNA family characteristic of Old World monkeys. The chromosomal localization of MFASAT, obtained by FISH, showed that this alphoid DNA is present in the peri-centromeric area of all the chromosomes. MFASAT showed a high degree of conservation when compared, by sequence alignment, to other Macaca species and Papio papio as expected for species with considerable genome conservation. A low degree of homology has been found comparing M. fascicularis alphoid DNA with a more distantly related Cercopithecidae species such as Cercopithecus aethiops.

[Drainage in thyroid surgery]

Bleeding represents a rare complication of thyroid surgery but when it occurs it may be life-threatening. To prevent this complication drainage is widely used. However no study has demonstrated the drains' value and recent reports have questioned its benefits. Therefore we have analyzed our experience of a 10 year-period in which 1.217 thyroidectomies were performed by the same surgical team and prophylactic routine drainage was always adopted. In 13 patients (1.06%) a benign hematoma occurred with spontaneous remission. In 6 patients the bleeding was severe and compressive hematoma occurred; it required surgical re-exploration. Such a complication is unusual in the neck surgery (0.49% in the authors' series) performed by experienced surgeons and when life-threatening hematomas do occur they depend on various uncontrolled factors and drainage is often not helpful. Otherwise a meticulous haemostatic technique is necessary and patients should be observed very closely during the few first hours following surgery on the thyroid gland. Therefore on the basis of the analysis of their series, although it is not always possible to prove the benefit of the drainage, the authors suggest its indication in the neck surgery, as in other fields with dead space, to remove blood and secretions reducing postoperative complications. They have never observed wound infections and patients were discharged within 72 hours.

[Vascular cysts of the adrenals. Association with aneurysm of the abdominal aorta]

A rare case of an adrenal vascular cyst associated to an abdominal aorta aneurysm is reported. Adrenal cysts are an uncommon clinical finding, in most cases incidentally discovered for nonspecific abdominal pain, during US, TC or RM evaluation or at autopsy. Small adrenal mass are clinically silent. They may be symptomatic (lumbar tension, pain) for dimensions over 10 centimetres. Cysts of large size can cause displacement and compression of adjacent organs. They present a difficult problem of differentiation between benign and malignant lesions. Non-neoplastic adrenal cysts have been divided into four categories: parasitic (7%), epithelial (9%), endothelial (45%) and haemorrhagic or pseudocystic (39%). Vascular adrenal cysts may be a traumatic consequence of an hamartomatous vascular anomaly. The aim of this paper is to discuss, on the basis of the literature, the etiology, diagnosis and treatment of the adrenal mass. Surgical timing is discussed for the concomitant vascular lesion. The elective treatment was left adrenalectomy performed through transperitoneal approach. Surgery for abdominal aorta aneurysm was differed because the adrenal mass was suspected to be an infected neoplastic lesion and for the feasibility of endovascular procedure. The adrenal specimens contained a cystic structure with fluid blood, fibrin and calcifications. Normal adrenal cortical tissue was found in the cystic wall. This lesion (arising from vascular anomalies) require separation from haemorrhagic adrenal neoplasm. Awareness of adrenal pseudocysts and careful attention to the hystological features aids this distinction.

Fine needle aspiration of a warthin-like thyroid tumor. Report of a case with differential diagnostic criteria vs. other lymphocyte-rich thyroid lesions

BACKGROUND

Warthin-like papillary carcinoma of the thyroid (WLT), a recently described entity, should be included among lymphocyterich lesions of the thyroid. The diffuse sclerosing variant of papillary carcinoma (DSV), the oxyphilic variant of Hashimoto thyroiditis (OHT) and primary lymphoplasmacytic lymphoma (PLT), the FNA appearances of which have many similarities, belong to the same category.

CASE REPORT

A case of WLT occurred in a 31-year-old female, who was admitted with a 1.5-cm, nodular lesion of the thyroid; fine needle aspiration (FNA) yielded a diagnosis of papillary carcinoma. Histologic examination revealed the characteristic picture of WLT, with papillae lined with large, oxyphilic thyreocytes, with nuclear pseudoinclusions and grooves filled with lymphocytes, mostly mature plasma cells. The FNA picture of WLT was compared with those of the other lymphocyticrich lesions of the thyroid--DSV, OHT and PLT.

CONCLUSION

The differences between these forms provide diagnostic criteria that could be useful for the preoperative management of patients affected by suspicious, inflammation like thyroid lesions.

[The non-recurrent inferior laryngeal nerve. Surgical experience]

During the performance of 1018 thyroid operations, 1497 recurrent laryngeal nerves were identified and exposed. Of the 773 visualized nerves on the right side, 2 were found to be non recurrent (0.26%). This abnormality may represent a pitfall during thyroidectomy even for very experienced thyroid surgeons. We emphasize that the exposure and preservation of this vital structure is the standard of care and an essential component of routine dissection in thyroid surgery.

[Hyperthyroidism and carcinoma of the thyroid gland]

The incidence of thyroid carcinoma in hyperthyroidism varies considerably from as low as 0.3% to as high as 16.6% with a higher rate in toxic nodular goiters. Occult thyroid carcinoma (< 1.5 cm or microscopic foci) is the rule and only a few tumors are suspected preoperatively with ultrasonography or fine needle aspiration or 131 I scan. In 408 patients who underwent surgery for hyperthyroidism in our Surgery Department from January 1967 through December 1994 the incidence of thyroid carcinoma was 5.6% (23 cases). In detail, a neoplasm occurred in 5 cases of Graves' disease (specific incidence: 3.8%), in 13 cases of toxic nodular goiter (12.5%) and in 5 cases of hyperfunctioning adenomas (2.8%). 19 cancers were papillary (12 in toxic nodular goiter, 3 in Graves' disease, 4 in hyperfunctioning adenomas), three were follicular (1 in Graves' disease, 1 in toxic nodular goiter, 1 in hyperfunctioning adenomas) and 1 medullary in Graves' disease. A papillary carcinoma was diagnosed preoperatively on fine needle aspiration with ultrasonography in only two patients with Graves' disease and confirmed by postoperative histological examination on permanent section. We do not believe in the frozen-section examination intraoperatively because it's not diagnostical for follicular lesions and evaluates rarely capsular invasion. Twenty patients received total thyroidectomy and four of them also lymphoadenectomy. Three patients received emithyroidectomy: in two cases for occult papillary carcinoma and in the last case for local cancer invasion (T4N0M0). Twenty patients are alive and with no evidence of cancer recurrence. Mean follow-up is 59.6 months. Our retrospective study shows a progressive increase of the incidence of coexisting thyroid malignancy and hyperthyroidism especially in toxic nodular goiter, probably related to extended surgical indications. Our findings do confirm that, even in the presence of hyperthyroidism, all thyroid nodules require careful diagnostics for exclusion of malignancy.

Increased frequencies of sister chromatid exchanges and micronuclei in "in vitro" lymphocyte cultures treated with the fungicides thiram and ziram

The two fungicides analysed in this paper, Thiram (TH) and Ziram (ZI) are among the most common residues found in fruit and vegetables sold in Italy. These compounds were tested in "in vitro" lymphocyte cultures, from 16 individuals, at different concentrations (Thiram 5 x 10(-8) M; 5 x 10(-7) M; 5 x 10(-6) M and Ziram 1 x 10(-7) M; 1 x 10(-6) M; 1 x 10(-5) M) in order to ascertain if they are able to modify sister chromatid exchange and/or micronuclei frequencies. Both fungicides produced a significant increase in SCE and Micronuclei frequencies. The two highest doses of TH and ZI were found to be cytotoxic for most of the individuals and were not included in the statistical analysis. With regard to the Proliferation Rate Index (i.e. the number of first, second, third or more mitoses), no difference was found between controls and treated cultures.

Cytogenetic effect of thiabendazole and diphenylammine on cultured human lymphocytes: sister chromatid exchanges and cell cycle delay

The two fungicides analysed in this paper, Thiabendazole (TBZ) and Diphenylammine (DPA), are among the pesticides found in higher concentration in fruits and vegetables sold in Tuscany. These compounds were tested in "in vitro" lymphocyte cultures at different concentrations and using 3 protocols; protocol 1: the cultures were treated with the fungicides for 48 h; protocols 2 and 3: the cultures were treated with fungicides for 4 h in the presence or absence of the metabolic activator S9 mix. Both fungicides produced a slight increase in the SCE frequency in the 48 h treatment, at the higher non-toxic concentrations tested, but not when exposed for only 4 h, with or without S9 mix. As far as concerns the Proliferation Rate Index (i.e. the number of first, second and third mitoses), Thiabendazole also produced a significant decrease in the replication rate of the treated cultures, while Diphenylammine did not produce any effect.

Baseline and mitomycin C (MMC)-induced sister-chromatid exchanges in XX and XY cells of Callithrix jacchus chimeric twins

Lymphocytes from chimeric individuals of the species Callithrix jacchus (Primates) were examined to evaluate differences in the frequency of sister chromatid exchanges (SCE) between XX and XY cells. The aim was to discover whether SCE differ according to genetic sex and whether XX and XY cells show a different sensitivity to SCE inducing agents. This experimental model has enabled us to eliminate the possible differences caused by environmental factors. The results obtained do not reveal significant differences between male and female cells, in either the baseline SCE frequency or that induced by mitomycin C at concentrations of 0.01 and 0.03 microgram/ml. No significant differences were observed in the distribution of high SCE frequency cells (HFC), even if it is possible to observe a higher level of exchanges in XX cells in each trial. With regard to the phenotypic sex, there appears to be a trend towards slightly higher SCE rates in females, even if results are not statistically significant.

Sister-chromatid exchange rates in XX and XY cells of ten chimeric Callithrix jacchus individuals

In order to ascertain whether or not sister-chromatid exchange (SCE) differs in relation to sex, SCE rates in XX and XY cells from 10 specimens of marmoset (Callithrix jacchus) were examined. The choice of this primate is particularly suitable for three reasons: most individuals have a chimeric constitution, the X chromosome is quite large and the Y chromosome is particularly small. Therefore, the influence of possible differences in their exposure to the external environment can be eliminated. The results obtained did not reveal any significant difference between SCE rates in male and female cells in any of the examined individuals.

[Therapeutic and prognostic possibilities in primary lymphoma of the thyroid]

Personal experience with small cell thyroid tumours is reviewed in the light of recent developments in diagnosis and treatment. All cases were examined by means of immunohistochemical investigation of the lymphocytic and epithelial antigens. In 7 cases in which the production of lymphocytic antigens was confirmed, a primary lymphoma of the thyroid was diagnosed. Immunohistochemical studies of the lymphocytic and epithelial antigens are essential in all small cell thyroid tumours, in order to differentiate between small cell anaplastic carcinomas and thyroid lymphomas. This differentiation is indispensable for the correct choice of treatment and an accurate prognostic assessment. In the case of lymphomas, combined surgical and radiation treatment adjusted to the clinical stage of the tumour is recommended.

[Advanced age and clinical staging in the prognostic evaluation of differentiated carcinoma of the thyroid gland]

The prognostic significance of age in differentiated thyroid tumours is assessed via the analysis of 156 cases of differentiated thyroid carcinoma surgically treated in 1967-85. A statistical analysis was performed on a sample of 120 patients under observation since their operation. The results indicate that the negative influence of old age is due more to the higher incidence of advanced tumours among the elderly than to more aggressive behaviour by the tumour.

Chromosome analysis in operating room personnel

Cytogenetic tests were performed on operating room personnel working in a Turin hospital. The aim of our study was to determine if any chromosome damage was caused by the use of anaesthetic gases. Blood samples were collected from 45 hospital workers: 15 exposed to anaesthetic gases, 15 exposed to both anaesthetic gases and ionizing radiations and 15 controls. An examination of sister-chromatid exchanges did not highlight significant differences when exposed subjects were compared to controls. Chromosomal aberrations were significantly higher (P = 0.029) in all the exposed personnel, while no statistically significant increase was observed in staff exclusively in contact with anaesthetic gases. Moreover there was a positive correlation for chromosome aberrations with the years of employment, when the entire exposed population was considered and when personnel from the different operating rooms were considered separately. Both sister-chromatid exchange and chromosomal aberrations were higher among smokers though differences were not statistically significant.