Abstract
Mucoepidermoid carcinoma (MEC), a common malignant salivary gland neoplasm, is generally divided into low-, intermediate-, and high-grade types according to the histologic features. To our knowledge, the present report describes the first case of dedifferentiation occurring in a low-grade MEC. A 55-year-old man presented with a biphasic neoplasm of the right parotid gland composed of low-grade MEC and dedifferentiated high-grade anaplastic undifferentiated carcinoma. Immunohistochemically, carcinoembryonic antigen expression was restricted to the low-grade MEC portion. The Ki-67-labeling index was higher in the dedifferentiated component than in the low-grade component. On image cytometric analysis, the low-grade MEC was diploid, whereas the dedifferentiated carcinoma was aneuploid. Although the patient was alive 10 years after the initial diagnosis, the tumor has recurred twice, at 3 months and 7 months after the initial resection. It is important to recognize that dedifferentiation can occur in a low-grade MEC, similar to other low-grade salivary gland carcinomas.
Original language | English (US) |
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Pages (from-to) | 1068-1072 |
Number of pages | 5 |
Journal | Human Pathology |
Volume | 34 |
Issue number | 10 |
DOIs | |
State | Published - Oct 2003 |
Keywords
- Case history
- Dedifferentiation
- Mucoepidermoid carcinoma
- Salivary gland
ASJC Scopus subject areas
- Pathology and Forensic Medicine