Molecular testing for thyroid nodules: Review and current state.

Thyroid nodules affect nearly two-thirds of the world population. Fine-needle biopsy with cytologic evaluation remains the diagnostic test of choice to distinguish benign from malignant thyroid nodules yet fails to discriminate as benign or malignant in up to one-third of cases. This review discusses the limitation of current cytopathologic evaluation, the development of thyroid molecular testing, and the strengths and limitations of commercially available tests. Initial cytomolecular testing sought to identify specific gene mutations associated with thyroid cancer. Although the presence of a mutation was strongly associated with cancer, the likelihood of identifying a mutation was low; therefore, the test had low sensitivity. Subsequent tests developed have sought to improve the accuracy of cytomolecular testing for thyroid fine-needle aspirations, both to reassure patients and providers when malignancy may be absent and to confirm the malignancy when present. The development of cytomolecular testing for thyroid nodules has informed and improved current understanding of thyroid nodule formation and progression. When used appropriately and with clear understanding of the advantages and disadvantages, cytomolecular testing has the potential to improve patient care in the setting of indeterminate thyroid nodules by helping to guide both the need for and the extent of thyroid surgery. Cancer 2018;124:888-98. © 2017 American Cancer Society.

Warthin tumor within the superficial lobe of the parotid gland: a suggested criterion for diagnosis.

The location of Warthin tumor (WT) in the parotid gland impacts the surgical approach and may be indicative of the elusive origin of this intriguing entity. Location in the deep versus superficial lobe of the gland is not directly addressed when defining WT characteristics. Our observation, of rare occurrence of deep lobe WT, if at all, led to the current investigation. The study design is cohort study. This is a retrospective chart review of all patients undergoing parotidectomy for WT in two tertiary academic referral centers: the Sheba Medical Center (SMC), Israel, and the Christiana Care (CC), Newark, Delaware, USA. 122 consecutive adult patients underwent parotidectomy for WT (72 from SMC and 50 from CC). Seventy percent were males, with a mean age of 60.6 years. Bilateral WT or multi-centric WT were found in 9.8 and 17.2% of the cases, respectively. In one case, the tumor was described as originating in the deep lobe. In all other cases, the tumor originated and was limited to the superficial lobe. 99.2% of WT originated in the superficial lobe, corresponding with the few reports directly addressing its location in the gland. The reason for the tumor to be limited almost uniformly to the superficial lobe is unknown, and could be related to the etiopathogenesis of this elusive entity. We suggest adding tumor location within the superficial lobe to the common characteristics of WT (male, smoking, and lower pole) that serve as "common criterion" while evaluating a parotid lesion.

Targeted Next Generation Sequencing with ThyroSeq v2.1 for Indeterminate Thyroid Nodules in Clinical Practice.

OBJECTIVE: To determine if patients elect molecular testing over diagnostic surgery or repeat fine needle aspiration for indeterminate thyroid nodules. Can ThyroSeq v2.1 molecular testing reduce diagnostic thyroid surgery and rule out cancer? STUDY DESIGN: Retrospective review Setting: Single institution, single-practice surgeon. SUBJECTS AND METHODS: Fifteen month retrospective review of indeterminate thyroid nodules that went on to ThyroSeq v2.1 testing. RESULTS: 286 patients met American Thyroid Association guideline criteria for surgeon- performed, ultrasound-guided fine needle aspiration for a thyroid nodule with on-site cytopathology. The indeterminate (Bethesda III or IV) fine needle aspiration cytology rate was 9.1 percent. Prevalence of malignancy in indeterminate nodules was 19 percent. 26/26 (100 percent) patients with indeterminate thyroid nodules elected molecular testing. 16 patients had no mutation, 9 had one or more mutations, and I had no result. 16 of 25 (64 percent) patients with no mutation elected not to undergo diagnostic surgery for indeterminate thyroid nodules. CONCLUSIONS: Patients demonstrated a strong preference for molecular testing instead of diagnostic thyroid surgery for indeterminate thyroid nodules. All patients in this series, 25/25 (100 percent) with indeterminate thyroid nodules elected molecular testing instead of repeat biopsy or diagnostic thyroid surgery. 16 of 25 (64 percent) patients tested had no mutation. All 16/16 (100 percent) patients with no mutation on ThyroSeq "rule out" testing elected active surveillance rather than surgery or biopsy, reducing diagnostic surgery. The risk of malignancy among mutation negative patients was not definitively established. There are a number of factors currently that may mute the power of "rule in" testing.

Contemporary diagnosis and management of Warthin's tumor.

OBJECTIVE: Determine if the pathophysiology of Warthin's tumor, clinical presentation, cytology, and frozen section analysis signal an opportunity for less invasive parotid surgery and reduced morbidity. STUDY DESIGN: Retrospective review of 120 human parotidectomies identified 50 consecutive Warthin's tumors. SETTING: Single surgeon, single institutional study. SUBJECTS AND METHODS: Surgeon performed ultrasound guided Fine Needle Aspiration (FNA) and intra-operative frozen section with nerve integrity monitoring were used in all cases. Partial superficial parotidectomy was performed in the initial 25 patients and extracapsular dissection in the subsequent 25 patients. RESULTs: Smoking history was acknowledged in 45/50 (90 percent) of patients. The mean age was 63. Lower parotid pain and cellulitis occurred 23/50 (46 percent) and 11/50 (22 percent), respectively. Tumor in the lower parotid pole occurred in 48/50 (96 percent). Frozen section diagnosis for Warthin's tumor was confirmed by final pathology in all 50/50 (100 percent) patients. Two of 50 patients (8 percent) in the partial superficial parotidectomy group and no patient in the extracapsular dissection group had transient facial nerve dysfunction (p > 0.05). CONCLUSIONS: Warthin's tumor presents with a high rate of symptomatic inflammation, overwhelmingly in the lower parotid pole. Cytology largely excludes malignancy. Frozen section analysis diagnosing Warthin's tumor is highly specific in predicting final diagnosis. Minimally invasive approaches can be performed with confidence with extracapsular dissection or partial superficial parotidectomy resulting in potentially reduced morbidity.

Proposal for standardized ultrasound analysis of the salivary glands: Part 1 submandibular gland.

Objectives: The Salivary Gland Committee of the American Academy of Otolaryngology-Head and Neck Surgery seeks to standardize terminology and technique for ultrasonograpy used in the evaluation and treatment of salivary gland disorders. Methods: Development of expert opinion obtained through interaction with international practitioners representing multiple specialties. This committee work includes a comprehensive literature review with presentation of case examples to propose a standardized protocol for the language used in ultrasound salivary gland assessment. Results: A multiple segment proposal is initiated with this focus on the submandibular gland. We provide a concise rationale for recommended descriptive language highlighted by a more extensive supplement that includes an extensive literature review with additional case examples. Conclusion: Recommendations are provided to improve consistency both in performing and reporting submandibular gland ultrasound.

Basement Membrane Mimetic Hydrogel Cooperates with Rho-Associated Protein Kinase Inhibitor to Promote the Development of Acini-Like Salivary Gland Spheroids.

Successful engineering of functional salivary glands necessitates the creation of cell-instructive environments for ex vivo expansion and lineage specification of primary human salivary gland stem cells (hS/PCs). Herein, basement membrane mimetic hydrogels were prepared using hyaluronic acid, cell adhesive peptides, and hyperbranched polyglycerol (HPG), with or without sulfate groups, to produce "hyperGel+" or "hyperGel", respectively. Differential scanning fluorescence experiments confirmed the ability of the sulphated HPG precursor to stabilize fibroblast growth factor 10. The hydrogels were nanoporous, cytocompatibile and cell-permissive, enabling the development of multicellular hS/PC spheroids in 14 days. Incorporation of sulfated HPG species in the hydrogel enhanced cell proliferation. Culture of hS/PCs in hyperGel+ in the presence of a Rho kinase inhibitor, Y-27632 (Y-27), led to the development of spheroids with a central lumen, increased the expression of acinar marker aquaporin-3 at the transcript level (AQP3), and decreased the expression of ductal marker keratin 7 at both the transcript (KRT7) and the protein levels (K7). Reduced expression of transforming growth factor beta (TGF-ß) targets SMAD2/3 was also observed in Y27-treated cultures, suggesting attenuation of TGF-ß signaling. Thus, hyperGel+ cooperates with the ROCK inhibitor to promote the development of lumened spheroids with enhanced expression of acinar markers.

Matrix Degradability Contributes to the Development of Salivary Gland Progenitor Cells with Secretory Functions.

Synthetic matrices that are cytocompatible, cell adhesive, and cell responsive are needed for the engineering of implantable, secretory salivary gland constructs to treat radiation induced xerostomia or dry mouth. Here, taking advantage of the bioorthogonality of the Michael-type addition reaction, hydrogels with comparable stiffness but varying degrees of degradability (100% degradable, 100DEG; 50% degradable, 50DEG; and nondegradable, 0DEG) by cell-secreted matrix metalloproteases (MMPs) were synthesized using thiolated HA (HA-SH), maleimide (MI)-conjugated integrin-binding peptide (RGD-MI), and MI-functionalized peptide cross-linkers that are protease degradable (GIW-bisMI) or nondegradable (GIQ-bisMI). Organized multicellular structures developed readily in all hydrogels from dispersed primary human salivary gland stem cells (hS/PCs). As the matrix became progressively degradable, cells proliferated more readily, and the multicellular structures became larger, less spherical, and more lobular. Immunocytochemical analysis showed positive staining for stem/progenitor cell markers CD44 and keratin 5 (K5) in all three types of cultures and positive staining for the acinar marker α-amylase under 50DEG and 100DEG conditions. Quantitatively at the mRNA level, the expression levels of key stem/progenitor markers KIT, KRT5, and ETV4/5 were significantly increased in the degradable gels as compared to the nondegradable counterparts. Western blot analyses revealed that imparting matrix degradation led to >3.8-fold increase in KIT expression by day 15. The MMP-degradable hydrogels also promoted the development of a secretary phenotype, as evidenced by the upregulation of acinar markers α-amylase (AMY), aquaporin-5 (AQP5), and sodium-potassium chloride cotransporter 1 (SLC12A2). Collectively, we show that cell-mediated matrix remodeling is necessary for the development of regenerative pro-acinar progenitor cells from hS/PCs.

Specific antibody titer alters the effectiveness of intrathecal enzyme replacement therapy in canine mucopolysaccharidosis I.

Intrathecal enzyme replacement therapy is an experimental option to treat central nervous system disease due to lysosomal storage. Previous work shows that MPS I dogs receiving enzyme replacement with recombinant human alpha-l-iduronidase into the cisterna magna showed normal brain glycosaminoglycan (GAG) storage after three or four doses. We analyzed MPS I dogs that received intrathecal enzyme in a previous study using an assay that detects only pathologic GAG (pGAG). To quantify pGAG in MPS I, the assay measures only those GAG which display terminal iduronic acid residues on their non-reducing ends. Mean cortical brain pGAG in six untreated MPS I dogs was 60.9±5.93 pmol/mg wet weight, and was 3.83±2.64 in eight normal or unaffected carrier animals (p<0.001). Intrathecal enzyme replacement significantly reduced pGAG storage in all treated animals. Dogs with low anti-iduronidase antibody titers showed normalization or near-normalization of pGAG in the brain (mean 8.17±6.17, n=7), while in dogs with higher titers, pGAG was reduced but not normal (mean 21.9±6.02, n=4). Intrathecal enzyme therapy also led to a mean 69% reduction in cerebrospinal fluid pGAG (from 83.8±26.3 to 27.2±12.3 pmol/ml CSF). The effect was measurable one month after each dose and did not differ with antibody titer. Prevention of the immune response to enzyme may improve the efficacy of intrathecal enzyme replacement therapy for brain disease due to MPS I.

Comparing capsule exposure using extracapsular dissection with partial superficial parotidectomy for pleomorphic adenoma.

UNLABELLED: The aim of this study was to compare capsule exposure using extracapsular dissection (ECD) with partial superficial parotidectomy (PSP) for pleomorphic adenoma. PURPOSE: Long-term favorable results for recurrence and facial nerve function have been reported for ECD and PSP for parotid pleomorphic adenoma. Extracapsular dissection is distinguished from PSP in that the facial nerve is dissected in PSP but not in ECD. This article attempts to answer the following hypothesis: the margin of normal parotid tissue surrounding a parotid pleomorphic adenoma is less for ECD compared with PSP. MATERIAL AND METHODS: This is a retrospective individual case-control study. Twelve consecutive parotidectomy procedures with a final pathology report of pleomorphic adenoma were retrospectively measured for margin (the percent of capsule exposure around the tumor). In 8 highly selected patients, ECD was performed. Four parotid surgical procedures not meeting strict criteria underwent PSP and served as controls. RESULTS: The eight patients with ECD had a mean of 80% (71%-99%) of the capsule exposed. The 4 PSP procedures had 21% (4%-50%) of the capsule exposed (P < .05). CONCLUSIONS: Extracapsular dissection results in higher capsule exposure.

A TGFßR inhibitor represses keratin-7 expression in 3D cultures of human salivary gland progenitor cells.

Salivary gland tissue engineering offers an attractive alternative for the treatment of radiation-induced xerostomia. Key to the success of this approach is the maintenance and expansion of secretory acinar cells in vitro. However, recent studies revealed that in vitro culture of primary salivary gland epithelial cells led to undesirable upregulation of the expression of keratin-7 (K7), a marker of ductal phenotype and frequently associated with cellular stress. We have previously shown that hyaluronic acid (HA)-based, RGDSP-decorated hydrogels support the 3D growth and assembly of primary human salivary gland stem/progenitor cells (hS/PCs). Here, we investigate whether the RGDSP culture also promotes K7 expression, and if so, what factors govern the K7 expression. Compared to hS/PCs maintained in blank HA gels, those grown in RGDSP cultures expressed a significantly higher level of K7. In other tissues, various transforming growth factor-ß (TGF-ß) superfamily members are reported to regulate K7 expression. Similarly, our immunoblot array and ELISA experiments confirmed the increased expression of TGF-ß1 and growth/differentiation factor-15 (GDF-15) in RGDSP cultures. However, 2D model studies show that only TGF-ß1 is required to induce K7 expression in hS/PCs. Immunocytochemical analysis of the intracellular effectors of TGF-ß signaling, SMAD 2/3, further confirmed the elevated TGF-ß signaling in RGDSP cultures. To maximize the regenerative potential of h/SPCs, cultures were treated with a pharmacological inhibitor of TGF-ß receptor, A83-01. Our results show that A83-01 treatment can repress K7 expression not only in 3D RGDSP cultures but also under 2D conditions with exogenous TGF-ß1. Collectively, we provide a link between TGF-ß signaling and K7 expression in hS/PC cultures and demonstrate the effectiveness of TGF-ß inhibition to repress K7 expression while maintaining the ability of RGDSP-conjugated HA gels to facilitate the rapid development of amylase expressing spheroids. These findings represent an important step towards regenerating salivary function with a tissue-engineered salivary gland.

Novel Multidisciplinary Salivary Gland Society (MSGS) Questionnaire: An International Consensus.

OBJECTIVES: First, establishment and validation of a novel questionnaire documenting the burden of xerostomia and sialadenitis symptoms, including quality of life. Second, to compare two versions regarding the answering scale (proposed developed answers Q3 vs. 0-10 visual analogue scale Q10) of our newly developed questionnaire, in order to evaluate their comprehension by patients and their reproducibility in time. STUDY DESIGN: The study is a systematic review regarding the evaluation of the existing questionnaire and a cohort study regarding the validation of our new MSGS questionnaire. MATERIALS AND METHODS: A Multidisciplinary Salivary Gland Society (MSGS) questionnaire consisting of 20 questions and two scoring systems was developed to quantify symptoms of dry mouth and sialadenitis. Validation of the questionnaire was carried out on 199 patients with salivary pathologies (digestive, nasal, or age-related xerostomia, post radiation therapy, post radioiodine therapy, Sjögren's syndrome, IgG4 disease, recurrent juvenile parotitis, stones, and strictures) and a control group of 66 healthy volunteers. The coherence of the questionnaire's items, its reliability to distinguish patients from healthy volunteers, its comparison with unstimulated sialometry, and the time to fill both versions were assessed. RESULTS: The novel MSGS questionnaire showed good internal coherence of the items, indicating its pertinence: the scale reliability coefficients amounted to a Cronbach's alpha of 0.92 for Q10 and 0.90 for Q3. The time to complete Q3 and Q10 amounted, respectively, to 5.23 min (±2.3 min) and 5.65 min (±2.64 min) for patients and to 3.94 min (±3.94 min) and 3.75 min (±2.11 min) for healthy volunteers. The difference between Q3 and Q10 was not significant. CONCLUSION: We present a novel self-administered questionnaire quantifying xerostomia and non-tumoral salivary gland pathologies. We recommend the use of the Q10 version, as its scale type is well known in the literature and it translation for international use will be more accurate. Laryngoscope, 132:322-331, 2022.

What is the best operative practice for small benign parotid pleomorphic adenoma?

Most surgeons will reduce the risk of recurrence and permanent facial nerve dysfunction with PSP for PPA with dissection and control of the facial nerve. High volume, very experienced parotid surgeons can offer ECD with the expectation of less transient facial nerve dysfunction, Frey's syndrome, and numbness. Long-term recurrence rates await further reports.

RGDSP-Decorated Hyaluronate Hydrogels Facilitate Rapid 3D Expansion of Amylase-Expressing Salivary Gland Progenitor Cells.

In vitro engineering of salivary glands relies on the availability of synthetic matrices presenting essential cell-instructive signals to guide tissue growth. Here, we describe a biomimetic, hyaluronic acid (HA)-based hydrogel platform containing covalently immobilized bioactive peptides derived from perlecan domain IV (TWSKV), laminin-111 (YIGSR, IKVAV), and fibronectin (RGDSP). The HA network was established by the thiol/acrylate reaction, and bioactive peptides were conjugated to the network with high efficiency without significantly altering the mechanical property of the matrix. When encapsulated as single cells in peptide-modified HA hydrogels, human salivary gland stem/progenitor cells (hS/PCs) spontaneously organized into multicellular spheroids with close cell-cell contacts. Conjugation of RGDSP and TWSKV signals in HA gels significantly accelerated cell proliferation, with the largest spheroids observed in RGDSP-tagged gels. Peptide conjugation did not significantly alter the expression of acinar (AMY1), ductal (TFCP2L1), and progenitor (KRT14) markers at the mRNA level. Characterization of three-dimensional (3D) cultures by immunocytochemistry showed positive staining for keratin-5 (K5), keratin-14 (K14), integrin-ß1, and α-amylase under all culture conditions, confirming the maintenance of the secretory progenitor cell population. Two-dimensional (2D) adhesion studies revealed that integrin-ß1 played a key role in facilitating cell-matrix interaction in gels with RGDSP, IKVAV, and TWSKV signals. Overall, conjugation of the RGDSP peptide to HA gels improved cell viability, accelerated the formation of epithelial spheroids, and promoted the expansion of the progenitor cell population in 3D. This work represents an essential first step toward the development of an engineered salivary gland.

Sialendoscopy and Sjogren's Disease: A Systematic Review.

OBJECTIVES/HYPOTHESIS: This study is a systematic review of the literature which seeks to estimate the expected treatment outcomes of a patient with Sjogren's syndrome (SS) undergoing therapeutic sialendoscopy. STUDY DESIGN: Systematic Review. METHODS: PubMed, Scopus, and Cochrane library databases were used to search for studies published as of August 2020 regarding the treatment outcomes of SS with sialendoscopy. The key search terms included "Sjogren's syndrome" and "sialendoscopy." Only studies in the English language involving more than one human patient were included. PRISMA guidelines were followed in study inclusion and data extraction. The primary outcome assessed was improvement in patient symptoms. RESULTS: Six studies met criteria and were analyzed in this review, including 125 patients undergoing sialendoscopy of parotid and/or submandibular glands as well as 25 controls. Of these patients, 90% were female with an age range of 18 to 79 years. There was significant diversity in outcome reporting tools. The outcomes of symptom improvement were pooled qualitatively based on improvement noted in each study. Outcomes were defined as partial improvement if the measured outcomes improved and complete improvement if measured outcomes resolved entirely. Despite the limited number of studies on this topic, this meta-analysis suggests that a similar study of therapeutic sialendoscopy could expect to provide at least temporary improvement of symptoms 90% to 99% of the time. CONCLUSIONS: This review provides support for the application of sialendoscopy in the treatment of SS salivary disease. Larger studies with consistent outcome reporting tools and control groups are needed to validate these results and provide a consistent therapy protocol. Laryngoscope, 131:1474-1481, 2021.

Immunosuppressed Miniswine as a Model for Testing Cell Therapy Success: Experience With Implants of Human Salivary Stem/Progenitor Cell Constructs.

An urgent need exists to develop large animal models for preclinical testing of new cell therapies designed to replace lost or damaged tissues. Patients receiving irradiation for treatment of head and neck cancers frequently develop xerostomia/dry mouth, a condition that could one day be treated by cell therapy to repopulate functional saliva-producing cells. Using immunosuppression protocols developed for patients receiving whole face transplants, we successfully used immunosuppressed miniswine as a suitable host animal to evaluate the long-term stability, biocompatibility, and fate of matrix-modified hyaluronate (HA) hydrogel/bioscaffold materials containing encapsulated salivary human stem/progenitor cells (hS/PCs). An initial biocompatibility test was conducted in parotids of untreated miniswine. Subsequent experiments using hS/PC-laden hydrogels were performed in animals, beginning an immunosuppression regimen on the day of surgery. Implant sites included the kidney capsule for viability testing and the parotid gland for biointegration time periods up to eight weeks. No transplant rejection was seen in any animal assessed by analysis of the tissues near the site of the implants. First-generation implants containing only cells in hydrogel proved difficult to handle in the surgical suite and were modified to adhere to a porcine small intestinal submucosa (SIS) membrane for improved handling and could be delivered through the da Vinci surgical system. Several different surgical techniques were assessed using the second-generation 3D-salivary tissue (3D-ST) for ease and stability both on the kidney capsule and in the capsule-less parotid gland. For the kidney, sliding the implant under the capsule membrane and quick stitching proved superior to other methods. For the parotid gland, creation of a tissue "pocket" for placement and immediate multilayer tissue closure were well tolerated with minimal tissue damage. Surgical clips were placed as fiduciary markers for tissue harvest. Some implant experiments were conducted with miniswine 90 days post-irradiation when salivation decreased significantly. Sufficient parotid tissue remained to allow implant placement, and animals tolerated immunosuppression. In all experiments, viability of implanted hS/PCs was high with clear signs of both vascular and nervous system integration in the parotid implants. We thus conclude that the immunosuppressed miniswine is a high-value emerging model for testing human implants prior to first-in-human trials.

Salivary gland disease in the era of COVID-19 pandemic.

Coronavirus disease 2019 (COVID-19) pandemic forced significant changes in current approach to outpatient evaluation of common otolaryngology complaints as hospitals around the world are trying to limit the spread of the virus and to preserve health care resources. These changes raise a lot of questions regarding patient triage and treatment decisions in clinical situations when it is unclear if the workup and management can be postponed. In this communication, we present our approach to evaluation and triage of new patients with complaints concerning for salivary gland disease.

The incidence and management of siaolocele after parotidectomy.

OBJECTIVES: (1) To determine if a postparotidectomy sialocele occurs at a higher incidence with a partial superficial parotidectomy compared with a near-complete parotidectomy and (2) to determine if needle aspiration versus observation yield more persistent sialoceles beyond 1 month. STUDY DESIGN: A single-surgeon, single-institution case series with a chart review. METHODS: Comparing 100 consecutive partial superficial parotidectomy procedures and 20 consecutive near-total parotidectomy procedures for formation of a postoperative sialocele. Patients were evaluated at 1 week and 1 month postoperatively. The first 18 sialoceles were treated with one or more needle aspirations. The last 21 sialoceles were treated with observation. RESULTS: There were 39 sialoceles in the partial superficial parotidectomy group (39/100, 39%) and none in the near-total parotidectomy group (0/20, 0%) (P < 0.05). All sialoceles resolved by the end of the first postoperative month whether aspirated or not aspirated. CONCLUSIONS: Sialoceles are common postpartial superficial parotidectomy, and they did not occur after near-total parotidectomy. Sialoceles can generally be treated by observation with an expectation of resolution within 1 month.

Pleomorphic adenoma: extracapsular dissection versus partial superficial parotidectomy with facial nerve dissection.

BACKGROUND: To determine if Extracapsular Dissection (ECD) versus Partial Superficial Parotidectomy (PSP) differ in terms of tumor recurrence and transient and permanent facial nerve dysfunction. ECD does not dissect the facial nerve. PSP dissects the facial nerve and provides a 1-2 cm margin around the tumor. METHODS: A 38-year Ovid Medline search (1970-2008) and an historical review with statistical analysis of published manuscripts were performed. RESULTS: Tumor recurrence occurred in 36/1183 (3.0%) ECD cases and 1/340 (0.3%) PSP cases; (p < 0.05). Permanent facial nerve dysfunction occurred in 22/1202 (1.8%) ECD cases and 2/924 (0.2%) PSP cases; (p < 0.05). Transient facial nerve dysfunction occurred in 112/1036 (11.8%) ECD cases and 142/793 (17.9%) PSP cases; (p < 0.05%). CONCLUSIONS: Historical review with statistical analysis of published series demonstrate a significantly higher rate of recurrent pleomorphic adenoma and permanent facial nerve dysfunction and a lower rate of transient facial nerve dysfunction with ECD compared to PSP.

Dynamic Assembly of Human Salivary Stem/Progenitor Microstructures Requires Coordinated α1ß1 Integrin-Mediated Motility.

A tissue engineering approach can provide replacement salivary gland structures to patients with hyposalivation disorders and xerostomia. Salivary human stem/progenitor cells (hS/PCs) were isolated from healthy regions of parotid glands of head and neck surgery patients, expanded, then encapsulated in biocompatible hyaluronate (HA)-based hydrogels. These bioactive hydrogels provide a surrogate territorial matrix suitable for the dynamic assembly, growth and reorganization of salivary gland components. This study examined the dynamics of salivary microstructure formation, growth, and reorganization using time-lapse imaging over 15 h. Immunofluorescence detection monitored production of individual basement membrane components forming around developing microstructures, and Ki67 assessed proliferation. Dynamic movements in hydrogels were quantified by measuring angular velocity (ω) of rotating salivary microstructures and changes in basement membrane architecture during microstructure growth. Integrin involvement in the dynamic reassembly was assessed using knockdown and inhibitor approaches. Single hS/PCs expanded over 5 days into spherical microstructures typically containing 3-10 cells. In larger macrostructures, proliferation occurred near the peripheral basement membrane that underwent growth-associated cycles of thinning and collapse. De novo secretion of laminin/collagen IV from reorganizing hS/PCs preceded that of perlecan/HSPG2. Microstructures routinely expressed ß1 integrin-containing complexes at basement membrane-associated regions and exhibited spontaneous and coordinated rotation during basement membrane maturation. ß1 integrin siRNA knockdown at the single-cell state prevented hS/PC microstructure growth. After microstructure formation, ß1 integrin knockdown reduced rotation and mean ω by 84%. Blockade of the α1 integrin subunit (CD49a) that associates with ß1 reduced mean ω by 66%. Studies presented here show that initial hS/PC structure growth and basement membrane maturation depends on α1ß1-integrin mediated signaling. Coordinated cellular motility during neotissue reorganization reminiscent of salivary gland acini was critically dependent both on hS/PC-secretion of laminin,collagen type-IV, and perlecan/HSPG2 and the force-driven interactions of α1ß1-integrin activation. We conclude that α1ß1-integrin plays a critical role in establishing human salivary gland coordinated structure and function, and that its activation in tissue engineered systems is essential to tissue assembly.

Serial patient-derived orthotopic xenografting of adenoid cystic carcinomas recapitulates stable expression of phenotypic alterations and innervation.

BACKGROUND: Patient-derived xenograft (PDX) models have significantly enhanced cancer research, and often serve as a robust model. However, enhanced growth rate and altered pathological phenotype with serial passages have repeatedly been shown in adenoid cystic carcinoma (ACC) PDX tumors, which is a major concern. METHODS: We evaluated the fidelity of ACCs in their natural habitat by performing ACC orthotopic xenotransplantation (PDOX) in salivary glands. FINDINGS: Our PDOX model enabled solid tumors to integrate within the local epithelial, stromal and neuronal environment. Over serial passages, PDOX tumors maintained their stereotypic MYB-NFIB translocation, and FGFR2 and ATM point mutations. Tumor growth rate and histopathology were retained, including ACCs hallmark presentations of cribriform, tubular, solid areas and innervation. We also demonstrate that the PDOX model retains its capacity as a tool for drug testing. INTERPRETATION: Unlike the precedent PDX model, our data shows that the PDOX is a superior model for future cancer biology and therapy research. FUND: This work was supported by the National Institutes of Health (NIH)/National Institute of Dental and Craniofacial Research (NIDCR) grants DE022557, DE027034, and DE027551.