Chia-Cheng Li

Intraoral Spitz nevus: case report and literature review.

Spitz nevi account for approximately 1% of all melanocytic nevi of the skin in children. Although Spitz nevi often develop in the skin of the head and neck, intraoral Spitz nevi are rare. These nevi contain epithelioid and spindle cells and exhibit cytologic and architectural atypia when compared with routine melanocytic nevi, and may be mistaken for atypical Spitz tumor, Spitzoid melanoma, or conventional melanoma. Here, we report a Spitz nevus on the buccal mucosa of an 11-year-old boy. The tumor was composed of a proliferation of mostly epithelioid melanocytes with a smaller spindle cell component. The melanocytes were positive for S100, MART-1, and p16 proteins, with HMB-45-positive cells located only in the basal cell layer and superficial lamina propria. Less than 5% of the nuclei were positive for MIB-1, and there were no mitotic figures. We review the literature on 7 previously reported cases of Spitz nevi.

Microfabrication of Cell-Laden Hydrogels for Engineering Mineralized and Load Bearing Tissues

Microengineering technologies and advanced biomaterials have extensive applications in the field of regenerative medicine. In this chapter, we review the integration of microfabrication techniques and hydrogel-based biomaterials in the field of dental, bone, and cartilage tissue engineering. We primarily discuss the major features that make hydrogels attractive candidates to mimic extracellular matrix (ECM), and we consider the benefits of three-dimensional (3D) culture systems for tissue engineering applications. We then focus on the fundamental principles of microfabrication techniques including photolithography, soft lithography and bioprinting approaches. Lastly, we summarize recent research on microengineering cell-laden hydrogel constructs for dental, bone and cartilage regeneration, and discuss future applications of microfabrication techniques for load-bearing tissue engineering.

Primordial odontogenic tumour: report of two cases

Primordial odontogenic tumour (POT) is a rare mixed odontogenic neoplasm that is composed of primitive ectomesenchyme resembling dental papilla, surfaced by odontogenic epithelium resembling inner enamel epithelium, without hard tissue formation. Most reported cases have presented in the posterior mandible as a well‐demarcated radiolucency associated with an unerupted tooth in the first two decades of life. The aim of this report is to describe the clinicopathological features of two more cases of POT.

Dendritic cell neurofibroma with pseudorosettes: a clinicopathologic and immunohistochemical study of 5 intraoral cases

OBJECTIVE We report cases of dendritic cell neurofibroma with pseudorosettes (DCNP) presenting in the oral cavity and discuss clinicopathologic and immunohistochemical features that differentiate this from other benign peripheral nerve sheath tumors. STUDY DESIGN DCNPs were identified over a 2-year period, and history and histopathologic features were reviewed. Common nerve sheath tumors from the same period were identified and compared. RESULTS Five intraoral cases of DCNP presented in 2 men and 3 women, with a median age of 59 years. Three presented on the buccal mucosa, and 2 presented on the tongue. Each exhibited a biphasic population of cells with pseudorosettes and strong CD57 positivity. CONCLUSIONS With 31 cases of DCNP reported, the most common site of occurrence is now the head and neck region. DCNPs exhibit a characteristic biphasic population of cells and strong CD57 positivity. Pathologists should consider this diagnosis when confronted with unusual neural lesions.

Understanding the Pathobiology of Head and Neck Squamous Cell Carcinoma

Head and neck squamous cell carcinoma (HNSCC) is one of the leading cancers in the world, although wide geographical variations do exist. HNSCC can be subcategorized into conventional HNSCC and HPV-associated HNSCC, exhibiting distinct clinical and histopathologic features. Awareness of the risks of smoking has fortunately contributed to the decreasing incidence of conventional HNSCC in the USA. However, the prevalence of HPV-associated HNSCC in the USA has been significantly increasing. Much progress has been made in the research of development and progression of HNSCC. In this article, we review the current concepts of the pathobiological mechanisms of HNSCC.