Date of Degree
MS (Master of Science)
John W. Hellstein
The objective of this study was to retrospectively evaluate the prevalence of perineural invasion in cases of mucoepidermoid carcinoma (MEC). The study will determine if previously assessed perineural invasion by original pathology reports would be increased by re-review of the originally hematoxylin-eosin-(H &E) stained slides as well as review of slides reacted immunohistochemically with S100 to enhance visualization of nerves. The study will also assess whether perineural invasion or its absence in MEC is associated with clinical outcome. Thirty-one cases of major and minor salivary gland MEC were reviewed for perineural invasion and compared to the perineural invasion status stated on the original pathology report when available (13/31). All H & E-stained slides were reviewed as well as S100-reacted sections of each case’s tissue blocks that contained tumor. Patient demographics and clinical outcome were collected from electronic medical records. Perineural invasion was identified in 23% (3/13) of tumors in the original reports, 13% (4/31) of the authors' re-review of the same slides, and 29% (9/31) when cases were reacted with S100. A positive relationship was seen between the discovery of perineural invasion on H & E-stained slides and a greater number of foci of perineural invasion. Perineural invasion and larger-diameter nerve involvement was significantly associated with death at 5-year follow-up. In conclusion, immunohistochemical enhancement improves the accuracy, ease and speed of perineural invasion determination. Perineural invasion is a significant factor in the decreased survival outcome of cases of MEC. These findings support continued inclusion of the presence or absence of perineural invasion as a grading parameter in MEC.
Mucoepidermoid carcinoma (MEC) is the most common malignant neoplasm of salivary glands. Through numerous retrospective studies, recurrent and metastatic behavior of MEC has been closely related to histopathologic grade and tumor stage. Tumor grade has been shown to affect the prognosis and treatment modality. However, grading criteria has been debated over the years. Specifically, tumor’s perineural invasion status has been controversial as to its effect on prognosis. From this study, we sought to validate whether perineural invasion is an appropriate parameter in grading MEC and to determine if the presence or absence of perineural invasion is associated with clinical outcome. Using the most objective histopathologic features with which to grade MEC, and subsequently determining prognosis or treatment modality is important for a patient’s survival and quality of life.
publicabstract, Carcinoma, Invasion, Mucoepidermoid, Perineural
Copyright 2015 Emily Lanzel