Infrahyoid Research Articles

Use sonography to assess swallowing in post-thyroidectomy patients

Every surgery which involved the patient’s neck may have the chance to affect muscle kinetics related to functions of swallowing and voicing. Ultrasound can be a non-invasive diagnostic tool and provides the real-time image to visualize muscle kinetics. A prospective case control study. The aim of our study was to record the swallowing movements of patients after uncomplicated thyroidectomy postoperative 4–6 weeks and postoperatively 6 months using ultrasound . The patient will drink 10 ml water continuously with a repetitive saliva swallowing test. Analyzing the sonographic images to record the movement of cricoids cartilage while swallowing, the elevated distance of the laryngeal box and the thickness of the belly of straps muscles to differentiated the inflammation status of muscles. Comparing these data with the normal cases can help us to define the diagnostic cut-off value for dysphagia and quantization the neck strangling objectively. The result revealed that the swelling of the strap muscles will affect the efficacy of laryngeal elevation and the motion of cricoid cartilage during the swallowing. This kind of examination for swallowing evaluation is convenient, quick, non-radiation, noninvasive, can help us to realize and focus on the real swallowing problem of the patient and improve the efficacy of the logopedic therapy.

Сhronological and topographic peculiarities of infrahyoid structures during embryonic period of human ontogenesis.

Background. A scientific investigation on prenatal development of neck structures is one of the key areas in human morphology. Such topicality is due to high frequency of congenital malformations in newborns,traumatic pathologies in adults and complications of odontogenic diseases. New research data on the problem of infrahyoid structures development in early embryonic and late prefetal period will lead to creation of new surgical ways of treatment and diagnostic criteria for various neck pathologies. Objective. Our study is aimed to examine sources, chronologic sequences and developmentalpeculiarities of infrahyoid structures in anterior neck region during early human ontogenesis. Methods. We have used specimens of human embryos and prefetuses, obtained from Chernovtsy Regional Pathologists Office. The research was conducted by the means of complex morphological methods: macro-and microscopy, three-dimensional reconstruction of histological slides and statistical analysis. Results. We have observed first germ of infrahyoid group of muscles in 6-week human fetuses(13,0 mm of parieto-coccygeal length (PCL)) which is visible as a large plate of fused muscle tissue. This tissue during next two weeks of development undergoes process of separation on smaller independent structures. In human prefetuses (14,0-20,0 mm of PCL)this presumptive tissue has signs of striation and nerve supply. The 9th week of PND is considered to be a finish point for separation process (prefetuses of 31,0 mm of PCL). Larynx cartilages are clearly visible in prefetuses of 31,0-32,0 mm of PCL. During middle prefetal period (8-9th month of PND) most of infrahyoid muscles, blood vessels and nerves follow closely the adult pattern. Conclusions. We have seenfirst signs of infrahyoid muscles precursors in 6-week human embryos, which can be considered as a first critical period in infrahyoid structures’ development. Separation of a common infrahyoid muscles germ is completed by the 9th week of middle prefetal period. The sternocleidomastoid muscle is developing from a common germ with that of trapezoid muscle. The 8th week of prenatal development can be considered as second critical period for possible congenital malformations development.

The Utility of Strap Muscle in Complex Type I Thyroplasties

Type I thyroplasty is a common procedure used to improve dysphonia secondary to glottic insufficiency caused by vocal fold paralysis, paresis, or bowing. Revision often involves more complex procedures that can be complicated by mucosal violation, hemorrhage, infection, and shifted or extruded implants. Intraoperative challenges can be managed successfully using autologous strap muscle rotation flaps. Review vocal fold medialization with strap muscle as a viable option for thyroplasty, particularly operations with inadvertent mucosal disruption. All operative records of the senior author's 30-year experience were queried for modified, complex, or revision type I thyroplasties. Each of these was reviewed, and only those utilizing autologous strap muscle rotation flaps for vocal fold medialization were included. Changes in voice quality were assessed using strobovideolaryngoscopic assessment of glottic closure and Voice Handicap Index-10 (VHI-10) scores when available. Seven patients were found to have undergone eight type I thyroplasty using autologous strap muscle flaps. Improved glottic closure was seen in all patients except one. This patient, complicated by a laryngeal fracture of unknown origin discovered at the time of surgery, had worse voice with strap muscle implantation intraoperatively; therefore, the patient's fracture was reduced, and medialization was postponed. All other patients reported improved voice quality both intra- and postoperatively. Pre- and postoperative VHI-10 scores were available for two of the seven cases with successfully implanted strap muscles. A decrease in VHI-10 was observed in both cases (mean = 11). No postoperative complications occurred in any patient. Although revision thyroplasties are relatively rare, they can be challenging. The seven cases presented herein illustrate the successful and safe use of autologous strap muscle rotation flaps for complex, revision type I thyroplasty procedures. They are particularly helpful in cases requiring additional soft tissue between the thyroid cartilage and mucosa in preparation for possible future medialization after Gore-Tex or Silastic implants, and for inadvertent mucosal disruption in which using a foreign implant might pose a risk of infection. Future studies should be performed with larger populations and longer follow-up to confirm the efficacy and safety of this procedure.

Function evaluation of laryngeal reconstruction using infrahyoid muscle after partial laryngectomy in 37 patients

Treatment of small laryngeal cancerous lesions (T1 and T2) is based on partial endoscopic or open surgery and radiotherapy. In addition to the oncological imperative, these techniques must optimally preserve the functions of breathing, swallowing and phonation. ObjectiveTo analyze the above functions in patients treated with supracricoid laryngectomy and reconstruction using infrahyoid muscle. Materials and methodsBreathing, swallowing and phonation were analyzed in 37patients treated in two institutes between 2005 and 2015. All patients undergoing the above type of reconstruction with a minimum 1year's follow-up were included. Respiratory study noted any tracheotomy and measured peak inspiratory flow. Preservation of cricoarytenoid units and nasogastric intubation time, and DHI-30 self-administered questionnaire results were collected to analyze swallowing function. Phonation was assessed on the VHI-30 self-administered questionnaire. ResultsThe rate of primary surgery without tracheotomy was 64.9% (13patients), with rapid resumption of oral feeding (mean intubation time, 13days). Mean VHI score was 28.3 and mean DHI 30score 2.7. Mean peak inspiratory flow was 203.3mL/min. ConclusionSupracricoid laryngectomy with reconstruction using subhyoid muscle is an alternative technique for the treatment of small laryngeal cancerous lesions, providing uncomplicated functional outcome.

AB005. Complications and management following tracheal resection and reconstruction

AB005. Complications and management following tracheal resection and reconstruction

Treatment and Outcomes in pT4 Well-Differentiated Thyroid Carcinoma

Locally advanced, pT4 well differentiated thyroid carcinoma is a relatively rare entity and the benefit of external beam radiotherapy (EBRT) is unclear. The purpose of this study is to evaluate locoregional control (LRC) and cancer specific survival (CSS) of patients with pT4 well differentiated thyroid carcinoma in the largest retrospective cohort to date. Electronic records of patients with pT4 well-differentiated thyroid carcinoma treated at our institution from 2001 to 2013 were reviewed. Log-rank test and multivariable Cox regression were used to establish factors impacting locoregional control and cancer specific survival. A total of 232 patients were treated during this time period. The most common histologies were papillary carcinoma (n=192) and follicular carcinoma (n=11). The median age was 58 and 61% were female. Median follow up time was 11 years. The median tumor size was 3.1cm (interquartile range: 2.0-5.0cm), 60% had multifocal disease, 33% lymphovascular invasion, 9% perineural invasion and 64% had node positive disease. Local invasion into the strap muscles was seen in 51%, trachea 33%, larynx 4%, pharynx 3%, and recurrent laryngeal nerve 1%. 22% patients had an R0 resection, 55% R1 and 23% R2. 92% patients received adjuvant radioactive iodine therapy. A total of 88 patients received external beam radiotherapy with a median dose of 60Gy. There were 7 acute grade 3 toxicities (3 dysphagia, 2 nausea, and 2 pain) and 7 late grade 3 toxicities in the cohort (2 dysphagia, 3 esophageal stricture, 1 pain, 1 laryngeal stenosis). There were no grade 4 toxicities observed. Ten year LRC was 65%, CSS was 85%, and OS was 75%. On multivariate analysis, older age (p=0.02, HR 1.02, 95% CI 1.0-1.04), larynx invasion (p=0.05, HR 3.32, 95% CI 1.0-11.0) and larger tumor size (p=0.01, HR 1.17, 95% CI 1.04-1.32) were associated with worse LRC. Older age (p<0.001, HR 1.10, 95% 1.06-1.15), lymphovascular invasion (p=0.002, HR 3.3, 95% 1.5-7.2), perineural invasion (p=0.02, HR 2.9, 95% 1.19-7.48), and tracheal invasion (p=0.009, HR 2.7, 95% CI 1.3-5.5) were associated with worse CSS. Adjuvant RT was not associated with improved LRC and CSS when the entire cohort was assessed. However, for patients with microscopic or macroscopic residual disease (R1 and R2 resection), adjuvant radiotherapy was associated with improved LRC on multivariable analysis (p=0.02, HR 0.45, 95% CI 0.23-0.90). Despite locally advanced disease; 10 year CSS was 85% in this cohort of patients with pT4 DTC. Adjuvant radiotherapy improved LRC for patients with R1 and R2 resections. There was a low rate of toxicity from EBRT for the cohort.

Clinical Significance of Gross Invasion of Strap Muscles in Patients With 1- to 4-cm-Sized Papillary Thyroid Carcinoma Undergoing Lobectomy.

Given the emerging evidence supporting the lack of prognostic significance of gross extrathyroidal extension invading only strap muscles (strap-gETE), this study investigated whether lobectomy is feasible for patients with strap-gETE. A retrospective cohort study was conducted with 636 patients who had 1- to 4-cm-sized papillary thyroid carcinoma (PTC) treated with thyroid lobectomy. Patients with gross invasion of perithyroidal organs other than strap muscles or synchronous distant metastasis were excluded from the study. Disease-free survival (DFS) was compared according to the presence of strap-gETE. Strap-gETE was present in 50 patients (7.9%), with the remaining 586 patients (92.1%) showing no evidence of gETE. During the median follow-up period of 7.4years, 6% of the patients with strap-gETE and 5.1% of the patients without gETE experienced structural persistent/recurrent disease (p = 0.99). No differences in DFS were observed between the two groups (hazard ratio [HR], 1.24; 95% confidence interval [CI], 0.38-4.08; p = 0.720). After adjustment for five major risk factors (age, gender, tumor size, multifocality, and cervical lymph node metastasis status) in the multivariate analysis, the presence of strap-gETE did not exhibit an independent role in the development of structural persistent/recurrent disease (HR 1.05; 95% CI 0.24-4.53, p = 0.950). Strap-gETE did not increase the risk of structural persistent/recurrent disease for the patients who underwent lobectomy for 1- to 4-cm-sized PTC. The study data support the limited role of strap-gETE in clinical outcomes and may broaden the indications for lobectomy for patients with PTCs.

Unusual branch of the lingual artery supplies the infrahyoid muscles.

Infrahyoid muscles are usually supplied by muscular arteries, originating from the superior and inferior thyroid artery and the internal thoracic artery. In this work, we reported a unilateral anatomical variation of the branching pattern of the lingual artery, which was observed during dissection studies at the University of Brescia. We found an accessory branch arising from the root of the lingual artery that run down medially and supplied the infrahyoid muscles. A similar case has not yet been reported in literature. Considering the current use of the infrahyoid muscles as pedicled myocutaneous flap for reconstructing surgical defects in the head and neck, this vascular variation appears interesting to be reported for appropriate clinical and surgical consideration.

Lymph node metastasis in suprasternal space in pathological node–positive papillary thyroid carcinoma

BackgroundThe objective of the current study was to investigate the clinical significance of the suprasternal space lymph node (SSLN) in pathological node-positive (pN+) papillary thyroid carcinoma (PTC) patients. MethodOne hundred and forty patients with pN + PTC who underwent neck dissection were enrolled into this study. SSLN was resected and used as a specimen to investigate the relationship of SSLN with several clinicopathological parameters. ResultsThe metastasis rate of SSLN was 20.7%. On univariate analysis, we found that SSLN metastasis was significantly associated with primary cancer site (inferior portion), strap muscle invasion, level III metastasis, Level IV metastasis and lymph node metastasis between sternocleidomastoid and sternohyoid muscles. On multivariate analysis, primary cancer site (inferior portion), strap muscle invasion, Level IV metastasis and lymph node metastasis between sternocleidomastoid and sternohyoid muscles were independent risk factors for SSLN metastasis of PTC. ConclusionFor pN + PTC patients, special attention should be paid to the issue of SSLN metastasis.

Morphometric Determination of Sex of Hyoid Bone

Abstract Background and Objectives The hyoid bone shows sexually dimorphic features, which could be used in the sex determination aspect of establishing the biological profile in the remains of skeleton. The aim of this study was to investigate morphometrical variations of the hyoid bone in South Indian population. Materials and Methods A total of 60 adult larynx specimens (30 male and 30 female) with attached hyoid bone were dissected out from postmortem cadavers. The infrahyoid muscles and thyrohyoid membrane were removed. Hyoid bone was dissected and dried completely. Total 10 measurements like length of each greater cornua, length of body, major transverse axis, total hyoid length on both the sides, breadth of hyoid, and height of body of hyoid were taken on each hyoid bone using a digital Vernier caliper. Results The range, mean, standard deviation, and level of significance of all 10 parameters of hyoid bone were calculated using standard statistical method. Most of the parameters showed significant difference between the values of male and female hyoid bones. Conclusion Values obtained for all 10 parameters of hyoid bone were higher in males compared with females, which is suggestive that male hyoid bones are larger in size compared with female hyoid bones.

Predictive Factors of Recurrence for Multifocal Papillary Thyroid Microcarcinoma With Brafv600e Mutation: A Single Center Study of 1,207 Chinese Patients.

Background: The American Thyroid Association (ATA) guidelines risk stratify Brafv600e mutated multifocal papillary thyroid microcarcinoma (BMPTMC) into different recurrence risk groups by the extent of extrathyroidal extension (ETE). These findings and modifications for BMPTMC need to be verified in additional studies.Methods: A retrospective cohort study was conducted in BMPTMC patients who underwent total thyroidectomy (TT) and central lymph node dissection (CLND) from 2008 to 2013. Overall, 1,207 patients were included, and predictive factors were identified by univariate and multivariate analysis over a mean 7.5-year follow up.Results: BMPTMC with ETE to capsule shows the same recurrence rate (3.8%) with intrathyroidal BMPTMC. Moreover, BMPTMC with ETE only to strap muscle, which belongs to high-risk group according to ATA guideline, shows relatively lower recurrence rate (13.3%) compared with some intermediate risk categories such as cN1 and >5 pN1. Multivariate analysis using a Cox proportional hazards regression model shows that total tumor diameter (TTD) is associated with significantly higher recurrence for BMPTMC with or without other risk factors (Hazard Ratio (HRO) = 9.86 [95%CI 5.35–18.20], p = 0.00; HRO = 2.32 [95%CI 1.12–4.85], p = 0.02; respectively), while Hashimoto thyroiditis (HT) is found to be protective against the recurrence (HRO = 0.51 [95%CI 0.33–0.79], p = 0.00; HRO = 0.47 [95%CI 0.25–0.89], p = 0.02; respectively).Conclusions: Taken together, capsular ETE and gross ETE to the strap muscles did not have the expected significant influence on recurrence for Chinese BMPTMC patients who underwent TT and CLND. Rather than the extent of ETE, TTD and the lack of HT were identified as predictors for recurrence among BMPTMC with or without other risk factors (vascular invasion, cN1, pN1>5, pN1>3 cm).

Robotic lateral cervical lymph node dissection via bilateral axillo-breast approach for papillary thyroid carcinoma: a single-center experience of 260 cases

To evaluate the feasibility and safety of robotic lateral cervical lymph node dissection via BABA, 260 thyroid cancer patients with suspected level II, III, IV, and Vb lymph node metastasis were selected. The lateral cervical compartment was exposed by splitting the sternocleidomastoid muscle longitudinally, and separating between the strap muscles and the anterior margin of the sternocleidomastoid muscle. The procedure was completed in 260 patients. Mean time for robotic lateral node dissection took 80 ± 21 min. The wound catheter was removed 6.3 days. Postoperative transient symptomatic hypocalcemia was observed in 51 patients, transient hoarseness in three, seroma in three, chyle leakage in two, and tracheal injury in one. 124 patients were confirmed to have lymph node metastasis on final pathological report. Average postoperative hospital stay was 6.5 days. Robotic lateral neck dissection by BABA is the acceptable operative alternative for thyroid cancer patients who wished to keep their surgical history private.

The Effect of Four-Channel Neuromuscular Electrical Stimulation on Swallowing Kinematics and Pressures

The purpose of this study was to evaluate the effectiveness of the sequential four-channel neuromuscular electrical stimulation system. As a prospective case-control study, ten healthy subjects and ten patients with dysphagia were prospectively enrolled. Swallowing with and without sequential four-channel neuromuscular electrical stimulation (suprahyoid, infrahyoid muscles) was evaluated via videofluoroscopic swallowing study and high-resolution manometry. Results showed that the sequential four-channel neuromuscular electrical stimulation significantly improved the videofluoroscopic dysphagia scale during thick-fluid swallowing in patients with dysphagia. Furthermore, the kinematic analysis of videofluoroscopic swallowing study showed a tendency that neuromuscular electrical stimulation reduced duration of hyoid bone movement during thin- or thick-fluid swallowing. The high-resolution manometry parameters-maximal pressure of velopharynx, tongue base, cricopharyngeal pressure, minimal upper esophageal sphincter pressure, area of velopharynx, upper esophageal sphincter activity time, and duration of nadir upper esophageal sphincter-during thin-fluid swallowing were significantly improve in both groups compared with the high-resolution manometry parameters without neuromuscular electrical stimulation. The sequential four-channel neuromuscular electrical stimulation may help improve the parameters of videofluoroscopic swallowing study, kinematic analysis of the hyoid bone movement, and high-resolution manometry during swallowing. Further investigations are needed to better examine the effects of neuromuscular electrical stimulation in patients with dysphagia.

Hyoid Periosteum Sutures: A Modified Tissue-Preserving Hyoid Suspension Technique for Obstructive Sleep Apnea.

To present and assess a new, simple, conservative modification of hyoidthyroidpexy using 2 sutures between hyoid periosteum and thyroid lamina. Included patients had obstructive sleep apnea with apnea hypopnea index >20. Through a small midline neck incision, 2 Vicryl sutures were applied between the hyoid periosteum and thyroid cartilage. Infrahyoid and suprahyoid muscles were not traumatized. In 19 patients, the mean apnea hypopnea index significantly dropped (P < 0.0001) from 51.5 ± 11.9 preoperatively to 10.1 ± 4.9 postoperatively. The mean lowest oxygen saturation significantly increased from 79.2 ± 10.2 to 89.5 ± 8.1 (P = 0.0015). Moreover, Epworth sleepiness scale showed significant improvements (P < 0.0001) as its mean diminished from 13.8 ± 2.9 to 5.3 ± 2.9. The hyoid periosteum sutures technique (simple modification of hyoidthyroidpexy) is considered effective easily applicable, less costly with limited tissue dissection. It could be combined with other procedures in multilevel surgery for obstructive sleep apnea.

Interobserver Variability in the Histopathologic Assessment of Extrathyroidal Extension of Well Differentiated Thyroid Carcinoma Supports the New American Joint Committee on Cancer Eighth Edition Criteria for Tumor Staging.

Background: Extrathyroidal extension (ETE) by papillary and follicular thyroid carcinoma can be associated with increased risk of tumor recurrence and mortality. In the seventh edition of its Cancer Staging Manual, the American Joint Committee on Cancer (AJCC) defined minimal ETE as the involvement of skeletal muscle (i.e., strap muscles) or perithyroidal soft tissue. The eighth edition of the AJCC Cancer Staging Manual has changed the criteria so that only grossly evident (macroscopic) ETE involving strap muscles (not microscopic ETE involving perithyroidal soft tissue) affects tumor staging. Summary: Concordance of identifying microscopic ETE (as well as extranodal extension by carcinoma metastatic to lymph nodes) was previously evaluated among 11 expert endocrine pathologists. The overall agreement rate was slight when rendering a diagnosis of ETE. Concordance was highest when pathologists assessed the spatial relationship of carcinoma to skeletal muscle. This article discusses the significance of these findings. It also reviews relevant anatomic and developmental considerations related to the boundaries of the thyroid. Conclusions: The results of the concordance study provide additional rationale supporting stringent criteria for diagnosing ETE, as proposed by the eighth edition of the AJCC Cancer Staging Manual. It is expected that these rigid morphologic criteria will potentially reduce interobserver variability and enhance consistency in the diagnosis and staging of thyroid carcinoma.

Report of a non-looped variant of ansa cervicalis with omohyoid innervation from accessory nerve branch and omohyoid attachment to mastoid process.

A variant of the innervation of the infrahyoid neck musculature is reported in which the typical looped ansa cervicalis structure is absent. In this variant, the infrahyoid muscles (sternohyoid, sternothyroid omohyoid and thyrohyoid) were innervated by a presumptive superior root of "ansa cervicalis" traveling with vagus nerve (CN X) and not branching from hypoglossal nerve (CN XII). The omohyoid muscle, typically innervated by the inferior root of ansa cervicalis, is instead innervated by nerve fibers branching from the accessory nerve (CN XI). This formation created a non-looping variant of ansa cervicalis. Furthermore, the omohyoid muscle did not attach to the hyoid bone but instead attached to the mastoid process of the temporal bone by merging its fibers superiorly and posteriorly with the clavicular portion of the sternocleidomastoid muscle, creating a "sternocleidoomomastoid" muscle innervated by a branch of accessory nerve. This variation was found in one black male cadaver from a cohort of 25 male and female cadavers. Only one variation of ansa cervicalis was observed. As neck dissections and surgical procedures of this region are performed for a variety of conditions-including coronary artery bypass grafting and metastatic neck disease-variations of this type are of broad clinical surgical importance.

SUN-589 Ectopic Thyroid Tissue within the Strap Muscle: An Unusual Finding

Ectopic thyroid tissue is an uncommon clinical finding of thyroid tissue in a location other than the normal position of the thyroid in the lower anterior neck. Most commonly, thyroid ectopia exists as a lingual thyroid at the base of the tongue or in other structures which are in close proximity to the thyroid, including the larynx, trachea, surrounding soft tissue and muscles, or within thyroglossal duct cysts. More broadly, thyroid tissue can be found within the Wolfler area, which is located from the inferior border of the mandible to the aortic arch. Less commonly, thyroid ectopia can be found in more distant sites. A 65-year-old female with a history of type 2 diabetes and a recently discovered multinodular goiter presented to our clinic for further evaluation. She has no family history of thyroid cancer or personal history of radiation exposure. Her TSH and free T4 were 0.59 ng/dL and 0.93 uIU/mL, respectively. Additionally, thyroid peroxidase antibodies were negative. A routine ultrasound exam revealed a nodular goiter with a dominant 4.8 cm right isoechoic low-risk thyroid nodule in addition to two separate 1 cm heterogeneous isoechoic masses located in the midline at the junction of the thyroid cartilage and hyoid bone. The masses did not contain discrete nodules. CT scan demonstrated the nodular thyroid gland, a 1.2 cm mass located anterior to the hyoid, and a 1.3 cm mass embedded in the left strap muscle without adenopathy. A nuclear thyroid scan demonstrated radioactive iodine uptake in both of these extrathyroidal masses confirming multiple sites of ectopic thyroid tissue. Fine needle aspiration was performed of the right 4.8 cm nodule and had a benign, Bethesda II, cytology. The patient notes pain when turning her head from the left to the right and has been, thus far, referred for surgical evaluation. Thyroid ectopia is a rare finding that, more commonly, exists in patients with underlying thyroid conditions. Once suspected, thorough evaluation, including a high-quality neck ultrasound in addition to cross-sectional images of the area from the mouth to the aortic arch, is indicated. If the nuclear scan confirms normal functional thyroid tissue, observation is indicated for future growth or nodule formation. If a nodule is found in the ectopic tissue or if a radioactive iodine uptake scan is not performed, then a fine needle aspiration should be considered so as to rule out the possibility of thyroid cancer or metastases. Surgery is not always necessary unless there is uncertainty of the diagnosis or if the patient is symptomatic. Rarely, thyroid ectopia can be found in unusual sites including within the strap muscle as illustrated in this case. Although mentioned in surgical textbooks, thyroid tissue within the strap muscles has not been reported in the recent literature; this finding is important for practicing endocrinologists to consider.

SUN-LB102 Uncommon Pathology of Neck Mass

Poorly differentiated thyroid carcinoma (PDTC) is an uncommon form of thyroid cancer, accounting for less than 5 % of all cases. It tends to be more clinically aggressive than differentiated thyroid cancers. While thyroidectomy is the mainstay of treatment, radioactive iodine plays an adjunctive role as well as TSH suppression with thyroid hormone. Some patients with advanced disease, may benefit from external beam radiation and/or systemic therapy. Case Description: A 94-year-old man presents with a left neck mass. His past medical history is significant for controlled hypertension. He notices a slowly growing mass while shaving over few months. He has no dysphagia, hoarseness, or shortness of breath. He has no history of radiation exposure and no family history of thyroid disease. A CT of the neck with contrast shows multiple pathologic appearing lymph nodes on the left side of the neck. The largest measures 5.4 x 4 x 3.9 cm, displacing the carotid space, and indenting the left internal jugular vein. The left lobe of the thyroid is heterogeneously enlarged compared to the right lobe with multiple irregular hypo-enhancing nodules. A fine-needle aspiration of the left cervical lymph node is positive for malignant large cells in sheets and clusters. Some clusters have a vague papillary/trabecular type arrangement. A total thyroidectomy and left level II-IV neck dissection is performed. Pathology shows multifocal poorly differentiated papillary thyroid carcinoma measuring 2.2 cm in greatest dimension with extensive necrosis. There is a background of lymphocytic thyroiditis. There is extensive vascular invasion (>4 foci) and extra-thyroidal extension invading only the strap muscles. There is metastasis to 7 of 12 examined lymph nodes. The largest metastatic deposit at level III measures 2.8 cm with extra-nodal extension. Tumor is negative for BRAF-V600, NRAS and TERT. His postoperative labs are as follows: TSH 346 (post-rhTSH) uiu/ml (0.5-5.0), free T4 0.87 ng/dl (0.6-1.15),Tg 1.0 ng/ml and anti-Tg <0.9 iu/ml. Adjuvant therapy with 125 mCi of I-131 is performed as well as thyroid replacement with levothyroxine 100 mcg daily. A whole-body scan shows residual uptake in the thyroid bed and increased uptake to the left of the thyroid bed. FDG PET scan shows 2 left parapharyngeal nodes with SUV of 6.94 (0.8 cm), SUV of 3.73 (1.8 cm). There is a focus of increased activity at lateral left thyroid bed SUV of 4.59. There is a right mediastinal paratracheal lymph node with SUV of 9.79 measures 1.5 x 1.2 cm. Considering patient age, external beam radiation is deferred with patient agreement as the risk outweighs the benefit. Patient will be followed by imaging closely. Conclusion: PDTC is an uncommon form of thyroid cancer. These tumors generally do not produce thyroglobulin and close monitoring with imaging is essential to detect early metastatic disease. Unless otherwise noted, all abstracts presented at ENDO are embargoed until the date and time of presentation. For oral presentations, the abstracts are embargoed until the session begins. s presented at a news conference are embargoed until the date and time of the news conference. The Endocrine Society reserves the right to lift the embargo on specific abstracts that are selected for promotion prior to or during ENDO.

OR30-6 Parathyroid Carcinoma as a Complication of Inadequately Treated Pseudohypoparathyroidism

Introduction Pseudohypoparathyroidism (PHP) is characterized by renal resistance to the effects of parathyroid hormone (PTH) resulting in hypocalcemia, hyperphosphatemia and elevated parathyroid hormone (PTH). Hypercalcemia in PHP has previously been reported to occur due to the development of tertiary hyperparathyroidism or due to over-replacement of calcitriol. This is the first reported case of parathyroid carcinoma in a patient with PHP. The presenting features were hypercalcemia and marked elevation of PTH over the course of 3 years. Clinical case A 47 year old woman with PHP type 1B presented for evaluation of hypercalcemia for the past 3 years. She was diagnosed with PHP at the age of 5 after a hypocalcemia seizure. At that time, she had hypocalcemia (5.5-6 mg/dl), hyperphosphatemia (9.3-9.7 mg/dl) and elevated PTH (2442 pg/ml, normal 160-360 pg/ml). Renal function was normal. Tubular reabsorption of phosphate was unchanged at 98% after an injection of PTH leading to the diagnosis of PHP. She had a long history of non-adherence to medication and multiple hypocalcemic seizures. She developed hypercalcemia (10.9 mg/dl), elevated PTH (1064.7 pg/ml, normal 12-88 pg/ml) and normalization of serum phosphate (2.8 mg/dl) at the age of 44 while on calcitriol 0.25 mcg daily. She remained hypercalcemic when calcitriol was stopped. Neck ultrasound revealed a 2.2 x 1.6 x 1.3 cm exophytic, hypoechoic nodule at the inferior pole of the left thyroid lobe with increased vascularity. It was irregularly marginated along the thyroid and had no clear border anteriorly along the strap muscles. Parathyroid exploration and total thyroidectomy was performed. Pathology revealed parathyroid carcinoma with multiple foci of vascular invasion and one focus of soft tissue extension. Post-operative PTH declined to 2.6 pg/ml and patient had recurrence of hypocalcemia (total calcium 6.5 mg/dl) due to which calcitriol was restarted. She developed hungry bone syndrome necessitating IV calcium for 2 days. Conclusion The initial presentation with spontaneous hypercalcemia and history of non-adherence with medication prompted concern for tertiary hyperparathyroidism but the PTH elevation was higher than in prior cases of tertiary hyperparathyroidism and had doubled over 3 years despite medical therapy with calcitriol raising concern for a neoplastic process. Rapid development of hypercalcemia in a patient with PHP should raise the suspicion for parathyroid carcinoma. PHP type 1B is associated with defects in the regulatory elements of GNAS1 whereas PHP type 1A is due to loss of function mutations in GNAS1. All cases of hypercalcemic hyperparathyroidism in PHP have been noted in PHP type 1B which indicates that the resistance to PTH in PHP type 1B is only relative and can be overcome when the PTH becomes markedly elevated. The PTH elevation was sufficient to excrete urinary phosphate and normalize the serum phosphate level.

SUN-611 A Rare and Interesting Case of Primary Thyroid Lesion as Anaplastic Cancer and Lymph Node Metastasis with Papillary Thyroid Cancer

Background: Anaplastic thyroid cancers are very rare accounting for 1-2% of thyroid cancer. It has been hypothesized that it may start from one of differentiated thyroid cancer up to 30% of cases but usually there will be evidence of differentiated thyroid cancer like PTC in thyroid. Here, we present a rare case of anaplastic thyroid carcinoma on thyroid gland with cervical lymph nodes also positive for papillary thyroid cancer with no evidence of PTC in thyroid gland. Clinical case: 54-year female with h/o primary hypothyroidism and thyroid mass for several years presented to ER with complaints of neck pain where CT scan showed large right thyroid mass with tracheal compression. She had noticed rapid growth of mass for last 1-2 months with some compressive symptom like neck pain and dysphagia. Later, FNA of right thyroid Mass showed atypical lymphoid cells in a background of Hashimoto's thyroiditis. PET scan showed Intense FDG uptake in right thyroid lobe, right supraclavicular LN and right level 2LN. Core biopsy of thyroid was performed which showed poorly differentiated neoplasm with spindle morphology and Immunohistochemistry result favor a thyroid undifferentiated neoplasm. She underwent Total thyroidectomy with neck dissection and final pathology showed large, 8 cm, anaplastic thyroid carcinoma with invasion into the strap muscle. 12/85 LN were positive for cancer among them 10 were PTC and 3 were anaplastic carcinoma. Due to large primary tumor being anaplastic it was decided against radioactive ablation and she was referred for external beam radiation. Thyroglobulin level was 2.8 (2.8 to 40.9 ng/ml) after 11 days from surgery with TSH 2.32 (0.35 - 3.74 iu/ml) and undetectable anti thyroglobulin antibody. She tolerated radiation treatment well and repeat Tg level had decreased to 0.1 ng/ml when checked 4 months after surgery with suppressed TSH. Conclusion: Anaplastic thyroid cancers are very aggressive, undifferentiated cancers with almost 100% fatality within 1 years. It is more common in female and occurs mostly after age 60 to 65. It is usually presented with rapidly enlarging mass. There can be h/o prior differentiated thyroid. Our case did not have evidence of primary PTC with in thyroid but at least 10/ 85 removed lymph nodes were positive for PTC which is unusual. Our case is rare and unusual due coexistence of PTC in LN without primary PTC and with large anaplastic tumor in thyroid. This case also teaches us if there is rapid growth of existence thyroid mass, we should watch for possible anaplastic thyroid cancer and should not delay biopsy.