Distributional characteristics of lymphatic vessels in normal human nasal mucosa and sinus mucosa

Advances in the Understanding of ocular and nasal lymphatics

Recent research advancements have enhanced our understanding of the lymphatic system in the eye and nasal region and its involvement in health and disease. The eye is an anatomical extension of the central nervous system and was previously believed to be devoid of lymphatic structures, except for the conjunctiva. However, Lymphatic vessels have been recently identified in the cornea (under pathological conditions), limbus, ciliary body, extraocular muscles, conjunctiva, lacrimal gland, optic nerve sheath, and lymphoid structures in the choroid and Schlemm's duct. These novel findings have significant implications in eye disease treatment; however, the mechanisms by which they preserve immune balance in the eye and eliminate metabolic waste and inflammatory cells remain nebulous. Furthermore, connections have been observed between ocular and nasal lymphatic vessels via the lymphatic network accompanying the nasolacrimal duct. The nasal lymphatic vessels are the primary pathway for cerebrospinal fluid drainage and a new route for drug delivery and treatment of brain-related diseases. This review provides an overview of recent advancements in understanding the structure and function of the ocular and nasal lymphatic systems and their association with cerebrospinal fluid drainage and various diseases.

Cancer of the paranasal sinuses in Germany: Data on incidence and survival from a population-based cancer registry

PURPOSE

This study aims to provide a broad overview of the epidemiology of cancer of the paranasal sinuses (PSC) in Germany. The data include information on incidence, staging, clinicopathological features and survival from one of the largest cancer registries in Europe.

METHODS

Population-based data on PSC diagnosed from January 1st, 2009 until December 31st, 2019 were retrieved from the German Centre for Cancer Registry Data (ZfKD). Age standardized incidence was calculated and relative survival estimates were computed by sex, histological subtype, age group and T-, N-, and M-Stage.

RESULTS

In total, 3975 cases were included in this study. The age-adjusted incidence rate (ASR) for PSC was 0.3/100,000 which remained stable during the observation period. The most frequent tumor localization was the maxillary sinus (41.9 %) and the most common histological subtype was keratinizing squamous cell carcinoma (kSCC) (44.3 %). All subtypes were predominantly found in the maxillary sinus except for adenocarcinoma and neuroendocrine carcinomas (SNEC), which were most frequently located in the ethmoidal sinus. The majority of the patients with a known T stage was diagnosed in tumor stage T4 (60.8 %). The overall 5-year relative survival (RS) for all patients with PSC was 52 %. RS dropped from 93 % for T1 stage tumors to 39 % for T4 tumors. RS was 58 % for N0 and 31 % for N+ cases, 54 % for M0 and 27 % for M1 cases.

CONCLUSION

Age-adjusted incidence for PSC is low and has been stable for the observed 11-year period. RS decreases continuously with increasing T-, N- and M-stage.

Pheno-Endotyping Antrochoanal Nasal Polyposis

PURPOSE OF REVIEW

Antrochoanal polyps (ACPs) are benign polypoid lesions arising from the inner wall of the maxillary sinus and extending into the choana. Although the diagnosis and treatment strategies of ACP have changed since this entity was first described, the underlying pathogenic mechanism of APC is poorly understood. This article reviews the current knowledge of the etiology, inflammatory parameters, and microscopic findings of ACP.

RECENT FINDINGS

The inflammatory pattern of ACP appears to center around a neutrophilic inflammation T1-dominant endotype. Apart from the inflammatory component of ACP, at the microscopic level, the presence of tissue remodeling, mostly fibrin deposition and edema, and cysts in the epithelium and lamina propria has been described. Although the origin of this T1-dominant endotype immune response of ACPs is not entirely clear, it could be related to a lymphatic obstruction mechanism. This review serves to define a phenotype of ACP with potential endotypes based on the characteristics of the inflammatory parameters, microscopic findings, and hypotheses about the pathogenesis of ACP.

Evaluation of the Pharmacokinetics of Intranasal Drug Delivery for Targeting Cervical Lymph Nodes in Rats

A well-developed lymphatic network is located under the nasal mucosa, and a few drugs that permeate the nasal mucosa are absorbed into the lymphatic capillaries. Lymph from the nasal cavity flows to the cervical lymph nodes (CLNs). In this study, we evaluated the pharmacokinetics of the direct transport of intranasally administered drugs to CLNs through the nasal mucosa of Wistar rats using methotrexate as a model drug. The drug targeting index, which was calculated based on the areas under the concentration–time curves after intravenous and intranasal administration, was 3.78, indicating the benefits of nasal delivery of methotrexate to target CLNs. The direct transport percentage, which was indicative of the contribution of the direct nose–CLN pathway of methotrexate after intranasal administration, was 74.3%. The rate constant of methotrexate from the nasal cavity to CLNs was 0.0047 ± 0.0013 min⁻¹, while that from systemic circulation to CLNs was 0.0021 ± 0.0009 min⁻¹. Through pharmacokinetic analysis, this study demonstrated that the direct nasal–CLN pathway contributed more to the transport of methotrexate to the CLNs than the direct blood–CLN pathway.

Conchal contractility after inferior turbinate hypertrophy treatment:A prospective, randomized clinical trial

OBJECTIVE

The aim of this study is to evaluate the effects of these two methods (Nasal corticosteroids (NCS) and radiofrequency (RF) application) on conchal contractility utilizing objective rhinologic measurement parameters.

METHODS

82 patients were presented with the complaint of nasal obstruction and diagnosed with inferior turbinate hypertrophy and were included in the study. Patients in Group 1 received NCS for 12weeks. Patients in Group 2 were administered RF to their inferior turbinates. Acoustic rhinometry and rhinomanometry tests with and without decongestant were performed.

RESULTS

In the evaluation of the contractility difference of rhinometry parameters, there was not a significant difference among pre and postoperative acoustic rhinometric parameters in Group 1. Whereas in Group 2, postoperative contractility difference was significantly decreased compared to preoperative values. In the evaluation of the contractility difference of rhinomanometric parameters, no significant difference was found between pre and postoperative values in Group 1. However, postoperative contractility difference was significantly decreased compared to preoperative values in Group 2 in terms.

CONCLUSION

Because the RF procedure produces fibrosis in the vascular tissues, inferior turbinates do not have a shrinking response to decongestant administration. Administration of NCS administration maintains the contractility function compared to RF application.

The Utility of Sentinel Node Biopsy for Sinonasal Melanoma

Objective  Report two positive sentinel node biopsies for sinonasal melanoma. Design  Retrospective review. Setting  Academic tertiary care center. Participants  Patients who underwent sentinel node biopsy for sinonasal melanoma between November 1, 2014 and November 1, 2015. Main Outcome Measures  Clinical course. Results  Two patients were identified. Patient 1 (83M) presented with a sinonasal melanoma anterior to the left inferior turbinate and was clinically N0 neck. Lymphoscintigraphy revealed two sentinel nodes in the ipsilateral and three in the contralateral cervical basins. The left level I sentinel node was positive for melanoma and lymphadenectomy showed no additional metastases. Patient 2 (71F) presented after incomplete resection of a sinonasal melanoma of the left posterior maxillary sinus wall and was clinically N0 neck. Lymphoscintigraphy with single-photon emission computed tomography (SPECT/CT) localization revealed one sentinel node in the parapharyngeal space and another in the ipsilateral cervical basin. Metastatic melanoma was found in both nodes and completion lymphadenectomy was negative for additional disease. Both patients developed distant metastasis in less than 1 year after surgical resection but responded well to adjuvant immunomodulatory chemotherapeutic agents. Conclusion  Sentinel node biopsy for sinonasal melanoma can provide crucial clinical evidence of regional metastasis prior to overt clinical signs and symptoms. This intraoperative tool has the potential to improve detection of regional metastasis and improve long-term outcomes of this aggressive malignancy.

Nasal lymphatics as a novel invasion and dissemination route of bacterial meningitis

Bacterial meningitis constitutes an infectious disease with high morbidity and mortality, characterized by complex pathophysiology. Neisseria meningitis, Streptococcus pneumoniae, Haemophilus influenzae type b and other pathogens are capable of invading the CNS and infecting the meninges due to the incorporation of virulence factors. The pathophysiologic theories concerning the route of infection in bacterial meningitis consider a general cascade of events involving nasopharyngeal or middle ear colonization, pathogen bloodstream dissemination, blood-brain and blood-cerebrospinal fluid barriers crossing, and finally entrance of the implicated pathogen into the subarachnoid space, survival and subsequent infection. However, these theories cannot adequately explain the high percentage of negative blood cultures especially in cases of neonatal meningitis. Also, they cannot address with certainty the pathogens' entry site in to the cerebrospinal fluid, since the presence of barriers could act against bacterial infection of the meninges. In addition, experimental models of S. pneumoniae meningitis indicate that the route of infection may be independent of bacteraemia. The documented direct communication between the nasal lymphatics and the subarachnoid space could provide a hypothesis explaining the pathophysiologic mechanisms of meningeal infection and overcoming all the limitations of the current theories. It could also explain the presence of negative blood cultures while meningeal inflammation is present. Furthermore, it could also interpret the occasional fulminating evolution of bacterial meningitis since intense host defenses and central nervous system barriers could be bypassed. In our current communication we examine the role of the nasal lymphatic pathway in the development of meningitis. It is apparent that better understanding of the infection and dissemination route for bacterial meningitis can provide the opportunity for a more effective treatment.

Proteomic analysis of normal human nasal mucosa: establishment of a two-dimensional electrophoresis reference map

OBJECTIVE

To construct a partial two-dimensional electrophoresis (2-DE) reference map of the proteins that compose normal human nasal mucosa.

DESIGN AND METHODS

Normal inferior turbinate mucosa samples were subjected to 2-DE, the protein spots were visualized by silver staining, and 78 spots were selected for analysis by mass spectrometry and bioinformatics. Reverse transcriptase polymerase chain reaction (RT-PCR) and immunohistochemical techniques were performed for validation and localization analysis.

RESULTS

Among the identified proteins, the largest functional groups included proteins associated with the human immune response and enzymes, particularly those of protein metabolism. Proteins participating in the cell cycle, cell division, calcium metabolism, and ion transport were also detected. The mRNA transcripts for 10 selected proteins were amplified by RT-PCR. Immunohistochemistry revealed that secretagogin was localized in the submucosal gland and calsenilin was localized in the epithelium and submucosal gland.

CONCLUSION

This database will serve as the basis for further comparative proteomic studies of nasal mucosal disorders.