Clinical and Radiological Study of Adenoid Cystic Carcinoma in Salivary gland, Sinonasal Tract and Nasopharyngeal

Abstract

Adenoid cystic carcinoma (ACC) is one of the most common primary malignancies of the major and minor salivary glands. ACC is an uncommon neoplasm that most frequently arises in salivary glands and related tissue in the head and neck region. Unlike head and neck squamous cell carcinoma, ACC is characterized by neural infiltration and abundant angiogenesis. The prognosis remains unsatisfactory, due to a high incidence of local recurrence and distant metastases that directly reduce the overall survival time. Primary salivary glands, sinonasal tract and nasopharyngeal ACC are uncommon tumors that are frequently misclassified, resulting in inappropriate clinical management. The purpose of this study was to to study the clinicopathological characteristics, imaging featuresand determine factors that impact recurrence of ACC. To improve the recognition and diagnosis of the disease, we conducted a retrospective review of 44 patients with salivary glands, sinonasal tract and nasopharyngeal ACC who were evaluated between 2010 and 2015. There were 23 men and 21 women were included in this study. CT and MRI was interpreted by experienced technologists, and the findings were reported by two experienced radiologists. The expressions of Staining for p63 and Ki-67 was performed. Our result shown ACC has distinct histologic features, with cribriform and tubular growth patterns of basaloid cells displaying a predominantly myoepithelial cellular phenotype. Middle or slightly low density on plain scan, mild or moderate enhancementon enhanced CT. Middle or slightly low signal on MRI T1WI sequence , middle or high signal on T2WI sequence , moderate to marked enhancement on enhanced T1WI middle or slightly low density on plain scan ,mild or moderate enhancementon enhanced CT. This neoplasm also had middle or slightly low signal on MRI T1WI sequence, middle or high signal on T2WI sequence, moderate to marked enhancement on enhanced T1WI. There were characteristics of common manifestations of malignant tumor including irregular and infiltratingmargin, cystoid or necrosis in the tumor, bony destruction, etc. This neoplasm also has uncommon clinical features of rare regional lymph node metastasis and a prolonged but relentlessly progressive clinical course. Clinical outcome in ACC is correlated to histologic grade. Perineural invasion was the most consistent predictors of poor outcome in head and neck ACC.