76 Fig. 5 Oncocytic mucoepidermoid carcinoma. a This solid highly inﬁltrative oncocytic lesion would be classiﬁed in some grading schemes as high grade. b The tumor cells have abundant granular eosinophilic cytoplasm. c Only rare foci with mucus cells are noted. This patient suffered one recurrence 8 years after diagnosis but is currently free of disease for almost 5 years Head and Neck Pathol (2009) 3:69–77 • • evolves that still retains predictive value, this notion may become more palatable). Regarding which system to use, understanding of the clinical expectations is necessary. In most practices in the United States, it is less acceptable for a low grade tumor to behave in an aggressive fashion than for a high grade tumor to behave indolently and possibly get overtreatment. Thus, the utilization of the Brandwein system or Healey system is preferable. Variants should still be graded in a similar fashion although limited evidence suggests that some variants may behave more indolently even if technically high grade. Conclusions Though histologic grading of salivary gland carcinomas is somewhat ﬂawed, it does have prognostic value. Carci- noma ex pleomorphic adenoma should no longer be considered a speciﬁc diagnosis, but rather, a category in which the carcinoma should be typed, graded and quanti- tated to impart more prognostically and therapeutically relevant data. The two tumor types for which speciﬁc grading systems have evolved are adenoid cystic carci- noma and mucoepidermoid carcinoma. Adenoid cystic carcinoma is graded based on growth pattern with solid growth imparting a poorer prognosis. Rarely, these tumors will undergo high grade transformation in which case the tumor will have a much higher predilection for lymph node metastases than a conventional adenoid cystic carcinoma. In mucoepidermoid carcinomas, standardized grading systems are more reproducible than generic grade assign- ment, but in their current form, they are cumbersome and time consuming. The outcome in the intermediate grade category is heavily dependent on the grading system used and is thus the most controversial with regards to man- agement and prognosis. The AFIP system downgrades tumors leading to aggressive behavior in the intermediate grade category while the Brandwein system upgrades tumors resulting in indolent behavior. References 1. Eveson JW, Auclair PL, Gnepp DR, et al. Tumors of the salivary glands: introduction. In: Barnes EL, Eveson JW, Reichart P, Si- dransky D, editors. World Health Organization classiﬁcation of tumours: pathology & genetics. Head and neck tumours. Lyon: IARCPress; 2005. p. 221–2. 2. Bell RB, Dierks EJ, Homer L, et al. Management and outcome of patients with malignant salivary gland tumors. J Oral Maxillofac Surg. 2005;63(7):917–28. 3. Myers EN, Ferris RL, editors. Salivary gland disorders. Berlin: Springer; 2007. 4. Lima RA, Tavares MR, Dias FL, et al. Clinical prognostic factors in malignant parotid gland tumors. Otolaryngol Head Neck Surg. 2005;133(5):702–8. 5. Lewis JE, Olsen KD, Sebo TJ. Carcinoma ex pleomorphic ade- noma: pathologic analysis of 73 cases. Hum Pathol. 2001;32(6): 596–604. 6. Lewis JE, Olsen KD, Weiland LH. Acinic cell carcinoma. Clin- icopathologic review. Cancer. 1991;67(1):172–9.