Thyroid Gland Invasion Research Articles

Mechanism of Thyroid Gland Invasion in Laryngeal Cancer and Indications for Thyroidectomy

Invasion of thyroid gland (TG) by laryngeal cancer is rare. However, ipsilateral hemithyroidectomy is routinely performed during total laryngectomy (TL) for laryngeal cancers. Even hemithyroidectomies are associated with hypothyroidism in 23-63% and hypoparathyroidism in 25-52%. Most of the studies on laryngectomy have advised thyroidectomy for T3 and T4 lesion, transglottic growth, subglottic disease or extension and involvement of anterior commissure. The role of tumour differentiation in TG invasion is unknown. The cases with TG invasion have been reported to have poorer prognosis. This is a retrospective study of 45 patients undergoing thyroidectomy along with TL. Of these, five had TG invasion. Extra-laryngeal soft tissue involvement [RR 1.89 (1.02, 4.24)] and transglottic growths [RR 1.18 (1.02, 1.36)] had a significant association with TG invasion. The mode of spread, contiguous or non-contiguous, depended on tumour differentiation. Well differentiated cancers had propensity for contiguous spread and moderately differentiated cancers for non-contiguous spread (p=0.05). The 5years survival of T4a cases was 30%. The difference in survival between TG invasion (p=0.618), cartilage invasion (p=0.111) and soft tissue infiltration (p=0.474) was statistically insignificant. Anatomically direct TG invasion can only occur through extralaryngeal soft tissue which is includes cricopharyngeus and cricothyroid muscles. We recommend thyroidectomy only when these muscles are involved by the tumour in case of well differentiated cancers. The probability of TG invasion increases with transglottic growths with subglottic extension more than 10mm. We recommend ipsilateral hemithyroidectomy in less differentiated cancers as they have propensity for non-contiguous spread.

Necessity of routine ipsilateral hemithyroidectomy during laryngopharyngectomy for pyriform sinus cancer

PurposeThe aim of this study was to revisit the role of hemithyroidectomy in the treatment of pyriform sinus cancer by determining the incidence of thyroid gland invasion by the tumor. Materials and MethodsMedical records of 27 patients with pyriform sinus cancer who underwent laryngopharyngectomy with ipsilateral hemithyroidectomy from 1999 to 2010 at a National Cancer Institute–designated comprehensive cancer center were retrospectively reviewed. Computed tomographic scans of the neck, operative notes, and surgical specimens were examined to determine the presence of thyroid gland invasion by imaging, clinical appearance, and pathology. ResultsThere were 19 male and 8 female patients (age range, 44-79 years; mean, 59.9 years). Most of the cases (85%) had advanced-stage disease. Extralaryngeal spread of tumor with thyroid cartilage invasion was noted in the computed tomographic scans of 5 patients; however, there was no radiologic evidence of thyroid gland invasion in any patient. No gross thyroid gland invasion by the tumor was appreciated in any patient during surgery. No histologic evidence of tumoral invasion of the thyroid gland was found in any of 27 surgical specimens. ConclusionsResults of this study suggest that thyroid gland invasion by pyriform sinus cancer is not common. Therefore, a routine ipsilateral hemithyroidectomy may not be necessary in the treatment of every patient with pyriform sinus cancer, unless there is evidence of thyroid gland invasion.

Accuracy of magnetic resonance imaging in diagnosing thyroid cartilage and thyroid gland invasion by squamous cell carcinoma in laryngectomy patients

We examined the accuracy of magnetic resonance imaging in assessing thyroid cartilage and thyroid gland invasion in patients undergoing total laryngectomy for squamous cell carcinoma, by comparing histopathology results with imaging findings. A retrospective study reviewed histology and magnetic resonance scan results for all total laryngectomies performed between 1998-2008 at University Hospital Aintree, Liverpool. Pre-operative magnetic resonance images were reviewed independently by two consultant head and neck radiologists masked to the histology; their opinions were then compared with histology findings. Eighty-one magnetic resonance scans were reviewed. There were 22 laryngectomy patients with histologically verified thyroid cartilage invasion and one patient with thyroid gland invasion. There were 31 patients with apparent radiological thyroid cartilage invasion pre-operatively (with 17 false positives), giving sensitivity, specificity, and positive and negative predictive values of 64, 71, 45 and 84 per cent, respectively. On assessing thyroid gland invasion, there were nine false positive scans and no false negative scans, giving sensitivity, specificity, and positive and negative predictive values of 100, 89, 10 and 100 per cent, respectively. Magnetic resonance scanning over-predicts thyroid cartilage and gland invasion in patients undergoing total laryngectomy. Magnetic resonance scans have limited effectiveness in predicting thyroid cartilage invasion by squamous cell carcinoma in laryngectomy patients.

Thyroid gland invasion in laryngopharyngeal squamous cell carcinoma: Prevalence, endoscopic and CT predictors

The authors studied the prevalence of histological thyroid gland invasion in laryngopharyngeal cancer and the preoperative endoscopic and CT signs predictive of this invasion. Retrospective study of patients with laryngopharyngeal squamous cell carcinoma (T3 and T4) treated by total laryngectomy or total laryngopharyngectomy associated with concomitant total thyroidectomy or ipsilateral lobectomy and isthmectomy. Eighty-seven patients were included. Eleven patients (12.6%) presented thyroid gland invasion. Subglottic tumour extension greater than or equal to 10mm (P=0.008) and cricoid cartilage destruction on CT (P=0.001) were statistically correlated with histological thyroid gland invasion. An intact appearance of the laryngeal cartilages on CT was associated with a low probability of thyroid gland invasion. Thyroid gland invasion must not be underestimated in patients with advanced laryngopharyngeal cancer. Preoperative CT is an essential part of the preoperative work-up. Thyroidectomy must not be performed systematically.

Factors Determining the Need for Thyroidectomy During Laryngectomy for Squamous Cell Carcinoma

Figure 1. CT images. (A) Subglottic extension and (B) thyroid cartilage invasion by SCCA larynx. Objective: To evaluate predictors for thyroid gland invasion in patients undergoing laryngectomy for SCCA of the larynx. Study Design: Retrospective chart review of a single tertiary care hospital. Methods: One-hundred forty-one charts were reviewed. Ninety patients underwent total laryngectomy for laryngeal SCCA between January 1993 and February 2009. Subjects were assessed based on tumor stage, preoperative evaluation (direct laryngoscopy and CT scan), and pathologic analysis. Outcomes included factors suggesting need for thyroidectomy. Results: Thyroidectomy was performed in 36/90 (40%) of patients and thyroid gland invasion by SCCA occurred in 7/36 (19%) cases undergoing thyroidectomy. In those specimens with thyroid gland invasion, 5/7 (71%) demonstrated both subglottic extension and thyroid cartilage invasion. Direct laryngoscopy had high specificity in identifying subglottic extension (p < 0.0001, 100% specificity), but poor sensitivity (60%). Computed tomography proved to be highly sensitive (100% sensitivity) in predicting subglottic extension (p = 0.01), thyroid cartilage invasion, and thyroid gland invasion, but was limited by its specificity (34%, 41%, and 36% respectively). Conclusions: Routine thyroidectomy in conjunction with laryngeal SCCA is unnecessary. Findings of both subglottic extension and thyroid cartilage invasion correlate positively with thyroid gland invasion, and suggest the need for thyroidectomy. However, preoperative prediction of these findings can be difficult. Abstract

Role of thyroidectomy in advanced laryngeal and pharyngolaryngeal carcinoma

Objective Total thyroidectomy (TThy) or hemithyroidectomy (HThy) in conjunction with a total laryngectomy (TL) or pharyngolaryngectomy (PL) for laryngeal carcinoma often results in hypothyroidism requiring life-long thyroid hormone replacement. The aims were to determine the incidence of thyroid gland (TG) invasion in patients undergoing TL or TPL with TThy or HThy for laryngeal or hypopharyngeal carcinoma and to assess predicative factors. Study Design Case series with chart review. Setting Guy's Hospital, London, UK. Subjects and Methods Thirty-five patients from 2004 to 2008 were reviewed. Specimens were examined to determine the incidence of TG invasion and predicative factors. Preoperative imaging was reviewed to assess the radiological evidence of TG invasion. Results TL and TThy were performed in 19 patients, TL and HThy in three patients, and PL and TThy in 13 patients. Surgery was performed for primary and recurrent carcinoma in 28 and eight patients, respectively. Histological evidence of invasion of the TG was found in three patients (8.5%). No significant relationship was found between TG invasion and patient's sex, subsite of primary carcinoma, stage of primary disease at surgery, degree of differentiation, or the presence of subglottic extension. In addition, no significant relationship was found between the presence of TG invasion and recurrent disease. Definite evidence of radiological invasion of the TG was seen in only one patient. Conclusions Invasion of the TG in patients undergoing TL or TPL is a rare event and limits the need for TThy in most cases.

Pathologic characteristics of resected squamous cell carcinoma of the trachea: prognostic factors based on an analysis of 59 cases

While squamous cell carcinoma (SCC) is the most common tracheal malignancy, few reports describe the pathologic considerations that may guide intraoperative decisions and prognostic assessment. We reviewed 59 tracheal SCC treated between 1985 and 2008 by segmental resection of the trachea, including resection of the carina in 24% and inferior larynx in 14%. We classified these tumors by grading histologic differentiation and microscopic features used in SCC of other sites. Of 59 tumors, 24% (14 of 59) were well differentiated, 49% (29 of 59) were moderately differentiated, and 27% (16 of 59) were poorly differentiated. Unfavorable prognostic factors were tumor extension into the thyroid gland (all of five so-afflicted patients died of tumor progression within 3 years) and lymphatic invasion (mean survival 4.6 versus 7.6 years). Keratinization, dyskeratosis, acantholysis, necrosis, and tumor thickness did not predict prognosis. As surgical resection is the only curative treatment; the surgeon should establish clean lines of resection using, as appropriate, intraoperative frozen section. The pathologist can provide additional important prognostic information, including tumor differentiation and extent, invasion of surgical margins, and extension into the thyroid.

SP199 – Accuracy of MRI in invasion of thyroid gland and cartilage

SP199 – Accuracy of MRI in invasion of thyroid gland and cartilage

Thyroid Gland Management in Total Laryngectomy: Meta-analysis

Objective 1. Review the incidence of thyroid gland invasion by squamous cell laryngeal carcinoma in the literature. 2. Correlate thyroid gland invasion with anatomical characteristics of the laryngeal tumor. Do laryngeal tumors which invade the thyroid gland share certain characteristics which can aid in determing the management of the thyroid gland during total laryngectomy? Methods Systematic review of MEDLINE (1967–2007) and EMBASE (1980–2007) for all total laryngectomy series which commented on thyroid gland invasion according to tumor subsite and pathological characteristics. These results were supplemented with 61 patients from our centers who underwent total laryngectomy with hemi- or total thyroidectomy. Eleven series in total (n = 535) were included in the meta-analysis (fixed effects model). Results Thyroid gland invasion was present in 47 laryngectomy specimens (9%); the main method of invasion of the gland was by direct extralaryngeal extension. Subglottic extension &gt; 10mm (OR 6.27 [2.16 to 18.19]; p = 0.0007), subglottic subsite (OR 4.32 [1.53 to 12.19]; p = 0.006), and transglottic subsite (OR 4.10 [1.75 to 9.57]; p = 0.001) were significantly correlated with thyroid gland invasion. Cartilagenous invasion by tumor was not a significant predictor of thyroid gland invasion (p&gt;0.05). Conclusions Thyroid gland invasion is not a general feature of squamous cell laryngeal carcinoma. When present, it is strongly associated with anteroinferior spread of laryngeal tumors. Thyroidectomy should only be performed during total laryngectomy for transglottic tumors, subglottic tumors, and tumors with subglottic extension &gt;10mm. In these cases, total thyroidectomy is warranted to maximize locoregional control.

Management of thyroid gland invasion in laryngopharyngeal cancer

Background and objectives The incidence of thyroid gland involvement in laryngopharyngeal cancer ranges from 0 to 23%. Therefore, ipsilateral hemithyroidectomy and isthmusectomy are routinely performed with total laryngectomy in many clinics. Hemithyroidectomy causes hypothyroidism in 63% of patients, and if combined with radiotherapy, the incidence increases to 89% of patients. But there is no consensus about using thyroid surgery in the treatment of laryngopharyngeal cancer. The purpose of this study was to identify criteria to use in the decision of whether, in cases of laryngopharyngeal cancer, hemithyroidectomy should be performed with total laryngectomy. Materials and methods The study group consisted of 28 patients with a mean age of 63.2 years (range 42–77 years). All patients were treated by thyroidectomy with total laryngectomy. We evaluated the incidence of thyroid gland invasion, clinical predisposing factors, pathologic features, and prognosis in cases of laryngopharyngeal cancer. Results The incidence of thyroid gland invasion was 14% (4/28). Subglottic extension was the only statistically significant factor in thyroid invasion. All cases of laryngopharyngeal cancer that invaded the thyroid gland had vocal cord fixation, anterior commissure invasion, and were advanced stage. The most common mechanism of spread to the thyroid was by direct extension through thyroid cartilage and anterior commissure. While the prognosis of patients with thyroid gland invasion was worse than that of patients with no invasion, the difference was not statistically significant. Conclusion Prophylactic thyroidectomy should be performed in cases of laryngopharyngeal cancer where there is subglottic extension of the tumor.

Predictors of Thyroid Gland Invasion in Glottic Squamous Cell Carcinoma

This study examines preoperative clinical and intraoperative histopathologic characteristics that can be used to predict thyroid gland invasion in the setting of squamous cell carcinoma (SCC) of the glottis. The study was retrospectively performed using 30 serially sectioned whole-organ total laryngectomy with thyroidectomy specimens with associated preoperative clinical data. Histopathologic and clinical variables including true vocal cord (TVC) fixation, cricoarytenoid joint invasion, subglottic extension (SGE) of tumor, patterns of laryngeal spread, and prior radiation were examined as univariate and multivariate correlates of thyroid gland invasion. Twenty-three percent of thyroid gland specimens demonstrated SCC invasion. Five were T4 stage, two were T3 stage, and all demonstrated direct extension to the thyroid gland. Of these, all had a fixed ipsilateral TVC (P = .003) and SGE of tumor greater than 15 mm (P = .003). Using multivariate analysis, SGE of tumor and TVC fixation contribute independently as correlates of thyroid gland invasion. Prior radiation of the larynx did not correlate with thyroid gland invasion and did not significantly influence the predictive capacity of these variables. Tumors invading the thyroid gland also invaded the cricothyroid membrane (100%), anterior commissure (100%), laryngeal ventricle (100%), and thyroid cartilage (86%). Preoperative assessment of TVC mobility and extent of SGE are significant correlates of thyroid gland invasion by SCC of the glottis. Distinct patterns of laryngeal spread are associated with thyroid gland invasion. Prophylactic hemithyroidectomy with isthmusectomy is indicated for glottic SCC in the preoperative setting of a fixed TVC and SGE greater than 15 mm. Additional study correlating patterns of laryngeal spread with thyroid gland invasion will add to these data in determining when to selectively perform thyroidectomy in this setting.

Parathyroid Carcinoma

Parathyroid carcinoma is a rare tumor that is responsible for <1% of cases of hyperparathyroidism in most parts of the world. An increased incidence of this tumor has been reported in patients with the hyperparathyroidism-jaw tumor (HPT-JT) syndrome, but the etiology of most other cases is unknown. Parathyroid carcinomas tend to occur a decade earlier than adenomas, and the sex ratio approaches unity in contrast to the female preponderance of adenomas. Most patients with carcinomas present with marked hypercalcemia and are more likely to have associated bone and renal disease than those with adenomas. Although fibrosis and mitotic activity are common in carcinomas, these features are not specific for malignancy. The diagnosis of carcinoma should be restricted to those tumors that show invasion of blood vessels, perineural spaces, soft tissues, thyroid gland, or other adjacent structures or to tumors with documented metastases. Mutations of the HRPT2 gene (1q21-q32), which are responsible for the HPT-JT syndrome, have been implicated in the development of a high proportion of parathyroid carcinomas. A subset of patients with mutation-positive carcinomas have germline mutations of the HRPT2 gene. This finding suggests that some patients with apparent sporadic parathyroid carcinomas may have the HPT-JT syndrome or a variant of this syndrome. Because of the high frequency of local recurrence following incomplete excision, an en bloc resection is the preferred surgical approach for treatment of parathyroid carcinomas.

Intraoperative management of the thyroid gland in laryngeal cancer surgery.

To determine if it is necessary to perform a hemithyroidectomy routinely with all total laryngectomies or if it should be reserved for selected cases. A retrospective analysis of 215 cases who had been operated on due to laryngeal cancer in our clinic between 1985 and 1999. In only 182 cases, hemithyroidectomy and isthmectomy were performed together with laryngeal surgery. Of these, 98% were male. Their ages ranged between 42 and 70 years. The tumour was located in the supraglottic region in 93 (51%) and in the glottic region in 24 (13%) cases. In 65 cases (36%), the tumour was transglottic. Twenty cases of transglottic tumours (31%) and 3 cases of glottic tumours (12.5%) were found to have subglottic extension. Total laryngectomy with unilateral or bilateral neck dissection and hemithyroidectomy on the tumour side plus isthmectomy were performed on all patients. On the pathologic specimens, subglottic extension was measured anteriorly and posteriorly from the free edges of the vocal cords. The specimens were stained with hematoxylin and eosin and examined under a light microscope. With glottic and transglottic carcinomas, the need for thyroidectomy may be based on the intraoperative assessment of the thyroid gland. In subglottic carcinomas, a hemithyroidectomy should routinely be performed. There may be no need to perform thyroidectomy in all total laryngectomy cases. The thyroid gland was invaded by squamous cell carcinoma in only 2 cases (1%). Both of these cases were transglottic tumours staged as T3 and T4 and had a subglottic extension more than 1 cm. We recommend routine hemithyroidectomy and isthmectomy during total laryngectomy only in cases with subglottic extensions more than 1 cm or thyroid cartilage invasion with tumour. In the other cases, assessment of extralaryngeal invasion and thyroid gland invasion by the tumour will determine whether thyroidectomy should be performed.

Metastatic involvement of draining paratracheal lymph nodes in hypopharyngeal carcinoma: a clinicopathological study

Histological evidence of metastatic involvement of paratracheal lymph nodes in hypopharyngeal carcinoma and its clinicopathological implications were studied. Twenty-five patients with hypopharyngeal carcinoma underwent total laryngopharyngo-oesophagectomy with complete paratracheal clearance. The incidence of positive paratracheal lymph nodes was 40% in hypopharyngeal tumours. Postcricoid lesions showed a higher percentage of positive nodes [50%] compared to those in posterior wall lesions [16.67%]. There was a statistically significant increase in the incidence of positive paratracheal lymph nodes with thyroid gland invasion, vocal cord invasion, metastasis to the internal jugular chain of the deep cervical nodes and extracapsular and perineural spread

Prognostic significance of thyroid gland involvement in laryngeal carcinoma.

We reviewed 173 laryngeal specimens that included thyroid tissue received from patients undergoing laryngectomy between 1966 and 1980 for evidence of thyroid gland invasion. Twenty-three (14%) of the larynges demonstrated thyroid involvement. In 15 specimens, involvement of the thyroid gland was by direct extension, and in eight the thyroid was involved metastatically. The survival in this group of patients was poor, with 18 patients dying of their disease within three years. Subglottic extension of 10 mm or greater was noted in 21 of 23 patients, and local recurrence was noted in 15 of 18 patients dying of their disease. The importance of removing one or both lobes of the thyroid gland in advanced laryngeal cancer is restated, and a surgically aggressive approach to the paratracheal nodes is recommended in patients with extensive subglottic involvement.