■ Squamous Papillomas Squamous papillomas are the most common benign neoplasms of the larynx and trachea, characterized by an exophytic squamous epithelium lining branching fibrovascular cores, often associated with human papillomavirus (HPV) infection. They may be solitary or may present…
▪ Vocal Cord Polyps and Nodules Vocal cord polyps and nodules represent reactive changes of laryngeal mucosa and adjacent stroma that result in a benign polypoid or nodular growth. The etiology is multifactorial, including laryngeal trauma (accidents or surgery), excessive…
Malignant tumors of the sinonasal tract (SNT) are rare, comprising less than 1% of all neoplasms and about 3% of those of the upper aerodigestive tract. Squamous cell carcinoma (SCC) and adenocarcinoma are strongly associated with environmental factors, including the…
▪ Sinonasal Papillomas The mucosa of the nasal vestibule and the superior wall of the nasal cavity are lined by squamous and olfactory mucosa, respectively. The remaining nasal mucosa consists of ciliated columnar epithelium of ectodermal origin known as the…
■ Rhinosinusitis Rhinosinusitis is defined simply as inflammation of the nasal cavity (rhinitis), paranasal sinuses (sinusitis), or both (rhinosinusitis). Clinical Features Rhinosinusitis is a common condition that can be caused by myriad etiologies, including allergies (most common), infections, aspirin intolerance,…
1 Introduction As an integral member of the preclinical study team, the toxicologic pathologist needs to have a thorough understanding of the laboratory animal model that serves as a test system for studies with pathology requirements. Genetic, microbial, experimental, and…
1 Introduction Toxicologic pathologists fill important roles in enabling the delivery of new medicines, chemicals, and other products that improve and save lives across the world. These include serving as study pathologists, peer review pathologists, sponsor pathologists, consultants, toxicologists, and…
1 Introduction Good Laboratory Practice (GLP) standards were authored by the United States Food and Drug Administration (FDA) to ensure sound and repeatable nonclinical safety assessment studies. They set the standard by which studies are planned, conducted, monitored, reported, and…
1 Introduction In vivo regulatory-type animal toxicity studies that include pathology endpoints are generally not hypothesis-driven experiments. Instead, these studies are meant to gather information using multiple, medical diagnostic endpoints, assessed both antemortem (i.e., in life) and postmortem, to discover or…
Acknowledgments The authors acknowledge previous authors of this chapter, Drs. Amy Brix and Ron Herbert. This work was supported in part by the NIH, National Institute of Environmental Health Sciences. 1 Introduction In general nonclinical toxicology studies conducted for hazard…