Percutaneous ethanol injection for treatment of cervical lymph node metastases in patients with papillary thyroid carcinoma.

OBJECTIVE: The objective of this study was to evaluate the technique, efficacy, and side effects of percutaneous ethanol injection in patients with limited cervical nodal metastases from papillary thyroid carcinoma. SUBJECTS AND METHODS: Fourteen patients who had undergone thyroidectomy for papillary thyroid carcinoma presented with limited nodal metastases (one to five involved nodes) in the neck between May 1993 and April 2000. All patients had received previous iodine-131 ablative therapy with a mean total dose per patient of 7,548 MBq. Ten of the patients either were considered poor surgical candidates or preferred not to have surgery, and all were unresponsive to iodine-131 therapy. Each metastatic lymph node was treated with percutaneous ethanol injection, and patients received both clinical and sonographic follow-up. RESULTS: Twenty-nine metastatic lymph nodes in our 14 patients were injected. Mean sonographic follow-up was 18 months (range, from 2 months to 6 years 5 months). All treated lymph nodes decreased in volume from a mean of 492 mm(3) before percutaneous ethanol injection to a mean volume of 76 mm(3) at 1 year and 20 mm(3) at 2 years after treatment. Six nodes were re-treated 2-12 months after initial percutaneous ethanol injection because of persistent flow on color Doppler sonography (n = 4), stable size (n = 1), or increased size (n = 1). Two patients developed four new metastatic nodes during the follow-up period that were amenable to percutaneous ethanol injection. Two patients developed innumerable metastatic nodes that precluded retreatment with percutaneous ethanol injection. No major complications occurred. All patients experienced long-term local control of metastatic lymph nodes treated by percutaneous ethanol injection. In 12 of 14 patients, percutaneous ethanol injection was successful in controlling all known metastatic adenopathy. CONCLUSION: Sonographically guided percutaneous ethanol injection is a valuable treatment option for patients with limited cervical nodal metastases from papillary thyroid cancer who are not amenable to further surgical or radioiodine therapy.

Anaplastic thyroid carcinoma: a 50-year experience at a single institution.

BACKGROUND: Anaplastic thyroid carcinoma (ATC) is among the most aggressive of human malignancies. However, there have been few large studies of histologically well-defined ATC. We report the results of a 50-year experience of this lethal malignancy. METHODS: We reviewed all cases of ATC managed in this institution between 1949 and 1999. One pathologist (J.R.G.) reviewed all pathologic material. Clinical details were obtained from medical records, and current status of all patients was determined. RESULTS: There were 134 cases, with a female-to-male ratio of 1.5:1 and a mean age of 67 years. Benign thyroid disease was present in 27 cases (20%) and well-differentiated thyroid carcinoma in 31 (23%). Sixty-two patients (46%) had distant metastases at diagnosis, and 98% of the tumors were locally invasive. Primary treatment was surgical for 96 patients (72%). Complete resection was achieved in 29 cases (30%), with "minimal residual disease" in 25. Neither extent of operation nor completeness of resection affected survival (P > .4). Postoperative radiotherapy gave slightly longer median survival (5 vs 3 months), which was not significant (P < .08). Multimodal therapy, including operation, chemotherapy, and radiotherapy, did not improve survival. CONCLUSIONS: The outlook for patients with ATC remains grim. Novel treatments for ATC are desperately needed.

Immunohistochemical analysis of sodium iodide symporter expression in metastatic differentiated thyroid cancer: correlation with radioiodine uptake.

The ability of thyroid cancers to concentrate radioiodine (RAI) is dependent, in part, upon the expression and functional integrity of the sodium iodide symporter (NIS). However, some differentiated thyroid carcinomas (DTCs) and most undifferentiated thyroid carcinomas lack the ability to concentrate iodide and are thereby insensitive to 131I therapy. Variation of NIS protein expression may be an important factor in this behavior. We wished to determine whether NIS protein expression in primary DTC tumors correlated with the subsequent RAI uptake by metastatic lesions in the same patients. We obtained paraffin-embedded tissue specimens from 60 patients with metastatic thyroid cancer who had undergone total or near-total thyroidectomy at the Mayo Clinic for DTC and had known presence or absence of RAI uptake in their tumor deposits determined by total body scanning after thyroid hormone withdrawal. Tissue sections from the primary intrathyroidal tumors were subjected to immunostaining (IS) using a monoclonal antibody against human NIS. Slides were subsequently examined for specific IS by two independent reviewers. For each patient, whole body scan (WBS) uptake was recorded, and correlation between results of IS and WBS was analyzed. Of 43 patients with a positive WBS, 37 also had positive IS of their tumors. In six patients with negative IS, a positive WBS was documented, and in three of these cases TSH at the time of surgery was less than 0.3 mIU/liter. Of the 17 patients with negative WBS, 10 were also negative on IS. Positive IS accurately predicted a positive scan in our study in 84% of cases; the ability of the IS to detect all cases with a positive scan was 86%, and it increased to 90% when patients who were receiving thyroid hormone therapy at the time of surgery were excluded from the analysis. Overall, the results of our retrospective study suggest that NIS IS of the thyroidal primary tumor in patients with papillary and follicular thyroid cancers has substantial ability to predict the behavior of subsequent deposits of metastatic and recurrent cancer with respect to iodine trapping and concentration. Our findings require confirmation in prospective studies to more accurately determine the predictive ability of the test and its role in the postoperative management of patients with DTC. If confirmed, NIS IS of DTC primary lesions may prove useful in the management of patients with known or suspected metastatic thyroid cancer.

Analysis of Hurthle cell neoplasms of the thyroid by interphase fluorescence in situ hybridization.

Recent studies have indicated that numerical chromosomal abnormalities including changes in p53 and cyclin D1 may be involved in Hurthle cell tumorigenesis. We analyzed a series of Hurthle cell neoplasms of the thyroid to evaluate the diagnostic and prognostic utility of numerical anomalies by DNA fluorescent probes for cyclin D1 and p53 gene loci and chromosomes 5, 7, 11, 12, 17, and 22. Interphase fluorescence in situ hybridization (FISH) analysis was performed on paraffin-embedded tissue sections from 10 Hurthle cell adenomas, 19 Hurthle cell carcinomas, and 7 normal thyroid tissues used as controls. Directly labeled fluorescent DNA probes for the centromere region of chromosomes 7, 11, 12, and 17 and locus-specific probes for chromosomes 5 and 22, cyclin D1, and p53 were utilized for dual-probe hybridizations. Sixty percent (6 of 10) Hurthle cell adenomas and 63% (12 of 19) Hurthle cell carcinomas showed chromosome gains. Twenty percent (2 of 10) Hurthle cell adenomas and 26% (5 of 19) Hurthle cell carcinomas showed chromosome losses. Normal thyroid tissues used as controls showed no chromosomal abnormalities. Among Hurthle cell tumors with chromosomal abnormalities, adenomas averaged 2.7 gains and 0.3 losses per case, and carcinomas averaged 3.3 gains and 0.6 losses per case. The two adenomas with chromosome losses each showed loss of one chromosome, whereas the five carcinomas with losses averaged 1.8 losses per case. Chromosome 22 was the most common loss identified, occurring in three of the 11 patients who died of disease. These results indicate that chromosomal imbalances as gains are common in both benign and malignant Hurthle cell neoplasms, but Hurthle cell carcinomas tend to have more chromosome losses than adenomas. Among Hurthle cell carcinomas in this study, chromosome losses were identified only from patients who died of disease. The loss of chromosome 22 may have prognostic value in Hurthle cell carcinoma of the thyroid.

Expression of the sodium iodide symporter in human kidney.

BACKGROUND: The human sodium iodide symporter (hNIS) is a transmembrane protein that mediates the active transport of iodide in the thyroid gland. Following cloning of NIS, NIS expression has been detected in a broad range of nonthyroidal tissues, suggesting that iodide transport in these tissues is conferred by the expression of functional NIS protein. METHODS: The aim of this study was to examine functional hNIS expression in kidney by reverse transcription-polymerase chain reaction (RT-PCR), ribonuclease protection assay (RPA), immunohistochemistry, and Western blot analysis accompanied by iodide accumulation studies in kidney cells. RESULTS: Using a pair of full-length hNIS-specific oligonucleotide primers, RT-PCR followed by Southern hybridization revealed hNIS mRNA expression in normal human kidney tissue. The PCR products were subjected to automated sequencing and revealed full identity with the published human thyroid-derived NIS cDNA sequence. Furthermore, positive protected bands indicating the presence of hNIS mRNA were apparent in RPA gel lanes corresponding to human kidney cells as well as Chinese hamster ovary (CHO) cells stably transfected with hNIS cDNA and Graves' thyroid tissue. Immunohistochemical analysis of normal human kidney tissue using a mouse monoclonal hNIS-specific antibody showed marked hNIS-specific immunoreactivity confined to tubular cells, while no hNIS-specific immunoreactivity was detected in the glomeruli. NIS protein expression in human kidney cells was further confirmed by Western blot analysis. In addition, accumulation of (125)I was detected in human kidney cells in vitro and was shown to be sodium dependent and sensitive to perchlorate. CONCLUSIONS: Functional hNIS expression was demonstrated in the renal tubular system, suggesting that renal iodide transport may be, at least in part, an active process driven by NIS.

Nondiagnostic thyroid fine-needle aspiration cytology: management dilemmas.

Approximately 10% to 20% of thyroid biopsies by fine-needle aspiration (FNA) are nondiagnostic. The management of thyroid nodules in which FNA is nondiagnostic remains controversial because few studies have addressed this issue. We retrospectively reviewed the medical records of 153 patients with nondiagnostic FNAs of the thyroid performed in 1994. Sixty patients had reaspiration biopsies performed. Thirty-seven specimens (62%) were diagnostic and 23 (38%) remained nondiagnostic. Of the 27 patients who had a thyroid operation, 10 (37%) had a malignancy. Preoperative information about physical examination, ultrasound imaging, or nondiagnostic FNA did not predict outcome. Nondiagnostic FNAs of the thyroid may be associated with a high probability of thyroid malignancy. Nondiagnostic FNAs should not be considered benign. Reaspiration followed by selective surgical treatment is recommended.

FHIT and TSG101 in thyroid tumours: aberrant transcripts reflect rare abnormal RNA processing events of uncertain pathogenetic or clinical significance.

OBJECTIVE: The chromosomal regions containing the two putative tumour suppressors, fragile histidine triad gene (FHIT) and tumour suppressor gene 101 (TSG101), are deleted frequently in thyroid tumours. We therefore analysed FHIT and TSG101 transcripts in a group of advanced thyroid tumours to establish their role in thyroid tumorigenesis. DESIGN: Retrospective analysis of FHIT and TSG101 mRNA transcripts and genomic DNA from cryo-preserved thyroid tumours. TP53, previously shown at the genomic level not to be mutated in this cohort of tumours, served as a control. PATIENTS: We analysed nine follicular thyroid carcinomas (FTC), six papillary thyroid carcinomas and six follicular adenomas (FA) and histologically normal thyroid tissue from four of the FA patients. MEASUREMENTS: Single stage and nested reverse transcription polymerase chain reaction (RT-PCR) products of FHIT, TSG101, and TP53 were analysed by agarose or polyacrylamide gel electrophoresis and sequenced. Genomic DNA was also analysed by polymerase chain reaction and sequencing (FHIT) or by Southern blotting (TSG101). Clinical data were correlated with the results of the mutation analysis. RESULTS: Truncated FHIT transcripts were observed frequently alongside full length transcripts with nested RT-PCR, most often in FTC, while single stage RT-PCR revealed only normal length transcripts in all tumours. Similar results were obtained for TP53, while abnormal TSG101 transcripts were detectable by single stage RT-PCR. Sequence analysis of the truncated FHIT and TSG101 transcripts revealed mainly exon skipping and alternate RNA processing events. Only a single point mutation (of TSG101) was found. Southern blotting for the TSG101 gene, and PCR amplification and sequencing of the FHIT gene showed no evidence of genomic abnormalities in either case, and there was no evidence of splice site mutations in the FHIT gene, suggesting that the truncated transcripts result from altered RNA processing. There was no relationship between tumour stage, grade or survival and the presence of FHIT or TSG101 abnormalities. CONCLUSIONS: Truncated FHIT and TSG101 transcripts in thyroid tumours reflect alternate mRNA splicing events, rather than genomic deletions. Such abnormal RNA processing seems to be common and widespread in thyroid neoplasms, as similar results were obtained by analysis of transcripts of TP53, which we had previously shown not to be mutated in these specimens. Although a pathogenetic role for these aberrant transcripts remains possible, no correlation was found with stage, histological grade or outcome in this small group of advanced thyroid malignancies. Relaxation of mRNA splice control appears to be a feature of follicular cell-derived thyroid neoplasms.

Pathologic features, proliferative activity, and cyclin D1 expression in Hurthle cell neoplasms of the thyroid.

Making a histologic distinction between Hurthle cell adenomas and carcinomas sometimes may be difficult. We analyzed a series of Hurthle cell lesions to determine whether specific histologic features and expression of Ki67 and cyclin D1 could be useful in distinguishing Hurthle cell adenomas from carcinomas. Formalin-fixed, paraffin-embedded tissues from 128 Hurthle cell neoplasms, including 59 adenomas; 55 carcinomas; and 14 tumors classified as neoplasms of uncertain malignant behavior (UMB), which had equivocal capsular invasion but no vascular invasion, were analyzed for expression of Ki67 and cyclin D1 by immunostaining. The distribution of immunoreactivity for Ki67 with antibody MIB-1 was analyzed by quantifying the percentage of positive nuclei that was expressed as the labeling index. None of the patients with adenomas or UMB tumors developed recurrent or metastatic disease after a mean follow-up of 7.8 and 7.9 years, respectively. Of the 55 patients with Hurthle cell carcinoma, 19 were associated with metastatic disease, 13 of whom died with disease. No patient with a Hurthle cell carcinoma without vascular invasion developed metastatic disease. The mean tumor size for Hurthle cell carcinomas (4.8 cm) was significantly larger than that of Hurthle cell adenomas (3.1 cm) or UMB tumors (3.7 cm). No patient with a Hurthle cell tumor smaller than 3.5 cm developed metastatic disease, even when vascular invasion was present. The Ki67 labeling index in Hurthle cell carcinomas (10.0 +/- 1.2) was 3-fold higher than in Hurthle cell adenomas (3.2 +/- 0.3). The Ki67 labeling index in the UMB group was 5.0 +/- 0.7. Cyclin D1 showed diffuse nuclear staining in 1 of the 59 (1.7%) Hurthle cell adenomas, in 10 of the 55 (18%) Hurthle cell carcinomas, and in none of the UMB tumors. In summary, analyses of the cell cycle proteins Ki67 and cyclin D1 in Hurthle cell thyroid neoplasms indicate that these markers may assist in distinguishing some Hurthle cell carcinomas from adenomas. Among the Hurthle cell carcinomas, large tumor size and vascular invasion are associated with clinically aggressive tumors. Our study also suggests that Hurthle cell neoplasms with only equivocal capsular invasion and no vascular invasion should behave in a benign manner.

Intranuclear holes (cytoplasmic pseudoinclusions) in parathyroid neoplasms, or "holes happen".

BACKGROUND: A parathyroid adenoma demonstrating intranuclear holes on aspiration cytology prompted a review of parathyroid neoplasms to determine the frequency of this phenomenon. METHODS: Aspiration cytology slides from 30 parathyroid adenomas and 1 parathyroid carcinoma were reviewed. In addition, histologic slides from 136 parathyroid adenomas and 7 parathyroid carcinomas were reviewed. Twenty-two cases had both cytologic and histologic slides available for review. The presence and approximate frequency of intranuclear holes were recorded. RESULTS: On cytologic smears, intranuclear holes were found in 3 of the 31 cases reviewed (2 adenomas and 1 carcinoma). The holes were frequent in only one adenoma (the index case) and moderate-rare in the other two cases. Review of tissue slides showed holes in 9 of 136 adenomas and 3 of 7 carcinomas; 2 adenomas and 2 carcinomas had frequent holes, whereas the remainder had holes infrequently. CONCLUSIONS: Intranuclear holes do occur in parathyroid neoplasia, in rare cases with considerable frequency. When intranuclear holes are observed in aspiration cytology specimens from the thyroid region, various thyroid and parathyroid conditions must be considered.

Impact of primary surgery on outcome in 300 patients with pathologic tumor-node-metastasis stage III papillary thyroid carcinoma treated at one institution from 1940 through 1989.

BACKGROUND: The pathologic tumor-node-metastasis (pTNM) system is universally used to define the extent of disease in human malignancies. This study evaluated the impact of initial therapy on cause-specific mortality (CSM) rates and recurrence rates in pTNM stage III papillary thyroid carcinoma. METHODS: Three hundred patients (median age, 58 years) were followed on average for 14 postoperative years. Of these, 246 patients (82%) had complete primary tumor resection; 208 patients (69%) had nodal metastases; 161 (54%) had locally invasive primary tumors; 45 patients (15%) underwent initial unilateral lobectomy (UL). Bilateral lobar resection (BLR) accounted for 242 patients (near-total, 54%; total thyroidectomy, 23%). RESULTS: The 30-year rates for CSM, distant metastases, nodal metastases, and local recurrence (LR) were 29%, 22%, 19%, and 16%, respectively. The 20-year rates for CSM were significantly higher (50% vs 14%) when primary tumor was incompletely resected (P = .0001). After complete resection, 20-year rates for CSM and LR after BLR were 12% and 10%, respectively, which were significantly lower (P < .05) than the 23% and 26% rates seen after UL. There were no significant differences in nodal metastases or distant metastases rates between UL and BLR (P > .4). The 20-year LR rate after total thyroidectomy (13%) was not different (P = .5) from the 11% seen after near-total thyroidectomy. CONCLUSIONS: In this nonrandomized evaluation of patients with pTNM stage III papillary thyroid carcinoma, the extent of primary thyroid resection appeared to significantly impact CSM and LR but did not apparently influence regional or distant metastasis.

Monoclonal antibodies against the human sodium iodide symporter: utility for immunocytochemistry of thyroid cancer.

The recent cloning of the thyroidal protein that is responsible for iodide transport, the sodium iodide symporter (hNIS), has made possible studies designed to characterize its structure, function and expression in thyroidal tissues. Using a mannose binding protein (MBP)-hNIS fusion protein as antigen, we have developed mouse monoclonal antibodies against hNIS to utilize as tools in such studies. Twenty-four clones were initially recovered which recognized the MBP-hNIS fusion protein, but only two of them were specific for hNIS while the others recognized MBP alone. Both antibodies were found to be immunoglobulin G (IgG) 1kappa (kappa). The specificity of antibodies was tested by Western blotting using membranes prepared from COS-7 cells transiently transfected with the pcDNA3 plasmid containing the full-length hNIS cDNA, or cells transfected with the pcDNA3 vector. A major band with a molecular weight (MW) of approximately 97 kDa, and several minor bands with MW of approximately 160 kDa, approximately 68 kDa, approximately 30 kDa and approximately 15 kDa, were detected specifically in the hNIS-transfected cells. After enzymatic deglycosylation, the major band was present at 68 kDa, as expected based upon the amino acid sequence of hNIS. Immunohistochemistry was performed with several different types of thyroid tissue and non-thyroidal tissues, using the monoclonal antibodies. Strong immunostaining was observed in Graves' tissue, with intermediate staining in papillary and follicular thyroid cancers and an absence of staining in Hürthle cell cancer. The staining was specific for the follicular epithelium and was concentrated in the basolateral portion of the cell membrane. These monoclonal hNIS antibodies should prove useful in the characterization of NIS expression in benign and malignant thyroid tissue and in studies characterizing its structure and function.

Analysis of human sodium iodide symporter immunoreactivity in human exocrine glands.

The human sodium iodide symporter (hNIS) is an intrinsic transmembrane protein that mediates the active transport of iodide across the basolateral membrane of thyroid follicular cells. In addition to normally functioning thyroid tissue, various extrathyroidal tissues, including salivary gland, lacrimal gland, gastric mucosa, choroid plexus, and lactating mammary gland, have been demonstrated to accumulate iodide. After cloning and molecular characterization of the sodium iodide symporter, expression of hNIS messenger ribonucleic acid has been detected in a broad range of extrathyroidal tissues using Northern blot analysis and RT-PCR. In this study we used both monoclonal and polyclonal antibodies directed against different portions of hNIS protein together with a highly sensitive immunostaining technique to assess hNIS protein expression in tissue sections derived from normal human salivary and lacrimal glands, pancreas, as well as gastric and colonic mucosa. Immunohistochemical analysis of normal human salivary and lacrimal glands revealed marked hNIS immunoreactivity in ductal cells and less intense staining of acinar cells. Further, immunostaining of gastric and colonic mucosa showed marked hNIS immunoreactivity confined to chief and parietal cells in gastric mucosa and to epithelial cells lining mucosal crypts in colonic mucosa. In normal human pancreas, hNIS immunoreactivity was located in ductal cells, exocrine parenchymal cells, and Langerhans islet cells. In conclusion, our study demonstrates the expression of hNIS protein by several human exocrine glands, suggesting that iodide transport in these glands is a specific property conferred by the expression of hNIS protein, which may serve important functions by concentrating iodine in glandular secretions.

Development of monoclonal antibodies against the human sodium iodide symporter: immunohistochemical characterization of this protein in thyroid cells.

The thyroid sodium-iodide symporter (NIS) is responsible for iodide concentrating ability within thyroid follicular cells. We sought to develop monoclonal antibodies against human NIS (hNIS) for use as reagents in structure-function studies of the protein, as well as potential tools in the assessment of NIS expression in benign and malignant thyroid tissues. Synthetic peptides corresponding to the second ExMD and to the carboxy-terminal ExMD of hNIS were produced and utilized as antigens to develop monoclonal antibodies, which were tested by Western blotting using membranes prepared from COS-7 cells transiently transfected with a pcDNA3 plasmid containing the gene for the full-length hNIS, or a control vector. Western blotting showed a major band with molecular weight (MW) of approximately 97 kDa and several minor bands with MW of approximately 160 kDa, 68 kDa, 30 kDa, and 15 kDa, all specific for hNIS-transfected cells. Immunohistochemistry was performed in various types of thyroid tissues and nonthyroidal tissues, using the monoclonal antibodies. Strong immunostaining was observed in Graves' tissue, intermediate staining in papillary and follicular thyroid cancer, and no staining in Hürthle cell cancer or in nonthyroidal tissue. The staining was specific for the follicular epithelium in each of the tissues and was most intense in the basolateral portion of the cell membrane. Overall, our observations indicate that the monoclonal antibodies are specific for hNIS and will be invaluable reagents for investigating the role of NIS in thyroid disease.

Hyalinizing trabecular adenoma of the thyroid gland: recognition and characterization of its cytoplasmic yellow body.

Many round, pale yellow, cytoplasmic inclusion bodies were found in hematoxylin and eosin-stained sections of a hyalinizing trabecular adenoma of the thyroid. The bodies were refractile and frequently had a microvacuolated or granular substructure. They were usually located close to the nucleus, often indented it, and rarely occurred within it. Histochemically, they showed a glycosaminoglycan, proteoglycan, and lipid content, displayed autofluorescence on exposure to ultraviolet light, and were unreactive with a variety of immunostains. Ultrastructurally, the inclusions were consistent with giant lysosomes, showing parallel whorled and arrayed membranes ("fingerprint" bodies) as a component of their substructure. Review of sections of 75 hyalinizing trabecular adenomas in our files revealed that the cytoplasmic bodies were present in all cases (100%), indicating that these inclusions most likely are a universal feature of the neoplasm.

Direct extension of malignant lesions to the thyroid gland from adjacent organs: report of 17 cases.

OBJECTIVE: To characterize malignant tumors with direct extension to the thyroid gland from adjacent organs. METHODS: We retrospectively studied 17 patients with direct extension of malignant tumor to the thyroid from primary lesions in the head and neck who had been examined at Mayo Clinic Rochester between 1985 and 1994. The origin of the primary tumor was identified in all cases. Thyroid involvement was confirmed histologically. Data were analyzed for the frequency and types of malignant lesions, the clinical course, and the follow-up after thyroid involvement. RESULTS: All 17 study patients had a diagnosis of a primary malignant tumor before detection of thyroid involvement. Of the 17 patients, 12 had squamous cell carcinoma (SCC) of the larynx, 2 had SCC of the tongue base, 2 had SCC of the proximal and the cervical esophagus, respectively, and 1 had synovial cell sarcoma of the proximal esophagus. The time between diagnosis of the primary tumor and detection of thyroid invasion in the patients with SCC of the larynx or tongue base ranged from 1 to 196 months (mean, 38). Only 1 of these 14 patients had thyroid gland involvement clinically evident before surgical exploration. Thyroid invasion was diagnosed after surgical intervention. All three patients with esophageal malignant tumors had thyroid involvement clinically. CONCLUSION: SCC of the larynx, tongue base, or proximal esophagus may invade the thyroid gland directly. SCC of the larynx may have the greatest tendency to extend to the thyroid. In patients with SCC, extension of the primary malignant tumor to the thyroid gland should be considered despite lack of clinical evidence.

Unilateral total lobectomy: is it sufficient surgical treatment for patients with AMES low-risk papillary thyroid carcinoma?

BACKGROUND: Controversy continues regarding the optimal extent of primary thyroid resection in most patients with papillary thyroid carcinoma (PTC), who are at minimal risk of cause-specific mortality (CSM). This study was designed to compare CSM and recurrence rates after either unilateral lobectomy (UL) or bilateral lobar resection (BLR) in patients with PTC considered low risk by AMES criteria. METHODS: Outcome was studied in 1685 patients initially treated during 1940 through 1991 and followed for up to 54 postoperative years (mean, 18 years). One thousand six hundred fifty-six patients (98%) had complete primary tumor resection; 634 (38%) had involvement of regional nodes. One hundred ninety-five patients (12%) had UL; BLR accounted for 1468 (near-total 60%; total thyroidectomy 18%). RESULTS: Thirty-year rates for CSM and distant metastasis were 2% and 3%, respectively. Twenty-year rates for local recurrence and nodal metastasis were 4% and 8%, respectively. There were no significant differences in CSM or distant metastasis rates between UL and BLR (P > .2). After UL, 20-year rates for local recurrence and nodal metastasis were 14% and 19%, significantly higher (P = .0001) than the 2% and 6% rates seen after BLR. CONCLUSIONS: UL was not associated with higher CSM rates, but it was associated with a significantly higher risk of locoregional recurrence. Thus BLR probably represents a preferable initial surgical approach to patients with low-risk PTC.

Sweat gland carcinoma: a clinicopathologic analysis of an expanded series in a single institution.

Primary adenocarcinoma of sweat glands is a rare tumor; approximately 220 cases have been reported in the last 30 years. We reviewed the charts of patients with primary diagnosis of this tumor treated at the Mayo Clinic between 1935 and 1995. We included only cases with initial histology slides available for re-examination. Tumors were classified into five recognizable histologic patterns (solid, ductal, mucinous, microcystic adnexal, and adenocystic carcinoma) and graded by the Broder system. Statistical analysis consisted of Kaplan-Meier product limit method and Cox multiple regression test. In total, 55 patients were identified, and age ranged from 13 to 85 years (mean 59 years). Thirty-six patients (65 percent) presented to the Mayo Clinic for initial treatment; all except one had disease limited to the primary site. Microcystic adnexal carcinoma was the most frequent type, and more than 50 percent were grade 2 tumors. Among these 36 patients, 4 had some type of recurrence. Patients who developed metastasis had a high-grade tumor in the initial biopsy. Nineteen patients were referred with recurrence; 13 had local recurrence, 4 had regional diseases, and 2 had distant metastases. The histologic distribution showed 47 percent solid tumors, and 37 percent of them were grade 3. Multiple regression analysis did not show a difference in recurrence or survival when gender, age, tumor location, or histologic pattern was evaluated. In addition, there was no difference in the outcome between wide surgical resection and micrographic surgery. The only predictive factor for distant metastases and/or death (p < 0.003) was histologic grade. Overall 10-year survival rate was 86 and 60 percent for primary and referred patients, respectively. We conclude that histologic diagnosis of sweat gland carcinoma must be complemented by clinical examination to evaluate metastases. Clinical behavior depends on the histologic type of tumor, degree of differentiation, and clinical stage. On recurrence, the likelihood of further recurrences and mortality increases dramatically. Aggressive initial local ablation with tumor-free margins is recommended. In high-grade tumors, prophylactic regional lymph node dissection may further characterize tumor aggressiveness and may justify adjuvant radiotherapy as part of the primary treatment.

Differential loss of heterozygosity at 7q31.2 in follicular and papillary thyroid tumors.

We analysed 42 differentiated thyroid tumors including 15 follicular adenomas (FA), 13 papillary thyroid cancers (PTC) and 14 follicular thyroid carcinomas (FTC) with 13 microsatellite markers specific for the long arm of human chromosome 7 within 7q31; this region is deleted frequently in several other tumor types. Overall, 20 of the 42 samples analysed (48%) displayed LOH with one or more of the markers tested. LOH was detected most frequently (78%) in FTC, the most malignant of the thyroid tumors. A smallest common deleted region (SCDR) was defined in this tumor type flanked by markers D7S480 and D7S490. This SCDR is distinct from D7S522, the most commonly deleted locus in many other tumors, which was deleted in only one FTC. D7S522 did show LOH in two of six informative PTCs. None of the PTC and only two of the FAs showed LOH in the FTC SCDR. Since FA is considered a premalignant stage of FTC, our results suggest that inactivation of a putative tumor suppressor at 7q31.2 may be acquired during adenoma to carcinoma progression. The absence of LOH at this locus amongst PTC suggests that inactivation of this tumor suppressor is specific for FTC. In conclusion, LOH at 7q31 is a frequent event in differentiated thyroid cancer, and we have defined a 2 cM SCDR specific for FTC.

Thyroid cancer in patients with familial adenomatous polyposis.

The association between thyroid cancer and familial adenomatous polyposis (FAP), albeit rare, is well known. It has been suggested that the thyroid tumors have unique histologic characteristics and may be follicular in origin. Because of their rarity, treatment and long-term prognosis are uncertain. Twelve such patients (prevalence 399/100,000) seen during 1949-1995 were retrospectively reviewed. Histology was independently re-reviewed by two pathologists. There were 11 female patients (two sisters) and 1 male patient, with a mean age of 28 years (range 15-61 years). Eight patients (66%) had multicentric tumors and five (42%) bilateral disease. Average tumor diameter was 1.8 cm (range 0.2-5.0 cm). Regional nodal metastases were present in two patients. All 12 thyroid cancers in this series were papillary. The one male patient demonstrated "typical" histology with variable papillary and follicular architecture, whereas the 11 female patients had tumors with unusual histology as described by Harach. Five patients (41%) were treated by total thyroidectomy, five with near-total thyroidectomy, and two with lobectomy alone. Mean follow-up was 142 months (range 7 months to 30 years). Regional recurrent disease occurred in two patients, one of whom died of the disease. The 5- and 20-year survivals were 90% and 77%, respectively. The results indicated that all tumors in this study were papillary, although atypical histology was encountered in 91%. The mean age (28 years) is younger than that of patients with sporadic disease. Multicentricity and bilateral disease are common. In view of this finding, total thyroidectomy should be strongly considered. Long-term prognosis is excellent. The finding of unusual histology in a young patient with papillary thyroid carcinoma should arouse the suspicion of FAP.

Treating recurrence of parotid benign pleomorphic adenomas.

Treatment for recurrence after surgical removal of parotid benign pleomorphic adenoma (PBPA) has not been well defined and is often followed by further recurrence. Surgery is overwhelmingly the most common approach. The risk of facial nerve injury is greater at reoperation since the nerve is less well defined. The value of radiation therapy (RT) has not been determined and incurs with it the risk of possible late occurrence of malignancy or nerve damage. The charts of patients with recurrent PBPA treated consecutively by a single surgeon from 1965 to 1993 were reviewed. All patients had a histopathologically verified diagnosis of PBPA both at the time of primary and subsequent surgeries. Follow-up was obtained from clinical charts and correspondence communication. Recurrence curves were generated using the Kaplan-Meier method. Thirty-nine patients with recurrent PBPA (36 referred and 3 treated primarily at Mayo) were evaluated. The patients were classified according to the type of surgery: 14 patients had previously undergone some form of parotidectomy or had only resection of the tumor for recurrence, and 25 patients underwent parotidectomy since this had not been performed primarily. The mean age in the two groups was 49 and 50 years respectively. The mean follow-up was 10 years after the recurrence treatment. The mean time between initial resection and recurrence in the two groups was 14 and 15 years. The mean time between the recurrence treatment and a second recurrence was 7.5 years. Nine patients had RT in addition to the local resection. Of this group 3 patients (33%) developed another recurrence. Five patients had local resection only, and of this group 1 patient (20%) developed another recurrence. Of the group that had superficial parotidectomy, 3 patients had additional RT and one of these patients (33%) developed another recurrence. Twenty-two patients had superficial parotidectomy only, and of this group 3 patients (14%) developed another recurrence. Only 2 of the 39 patients had complications. One patient developed Frey's syndrome after superficial parotidectomy and 1 patient developed facial paralysis after RT. As in other series, the number of patients is inadequate to allow for firm conclusions. However, it appears that when previous parotidectomy has been performed, simple excision with a margin of surrounding tissue would seem appropriate. Parotidectomy should be carried out if not performed previously. In simple excision after previous parotidectomy, there is a greater risk to the facial nerve because of difficulty in distinguishing the facial nerve from surrounding scar tissue. Our preference is to use general anesthesia so that branches of the nerve are not paralyzed and stimulation of the nerve aids in safe dissection. The value of RT is still indeterminate.