Oncocytic lipoadenoma of the parotid gland with sebaceous differentiation. Study of its keratin profile
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Oncocytic lipoadenomas of salivary gland are extremely rare tumors with only two previously reported cases. In this paper, we describe an additional example of oncocytic lipoadenoma showing sebaceous differentiation, a hitherto unreported occurrence. The tumor was encapsulated and measured 3 × 2.5 × 2 cm. Microscopically, the tumor comprised a mixture of oncocytes with “light” and “dark” cells intimately associated with mature adipose tissue. The oncocytes were positive for low molecular keratin, epithelial membrane antigen (EMA), and keratin 7, with only a small subgroup of cells expressing high-molecular-weight keratin, keratin 5/6, keratin 19, and p63. Terminally differentiated sebaceous cells were positive for EMA and keratin 14 only. Calponin and actins were negative, indicating a lack of myoepithelial cells in the tumor. The keratin profile and p63 expression of this oncocytic lipoadenoma suggest the presence of a dual cell population somewhat similar to the dual cell population described in some ultrastructural studies of pure salivary gland oncocytomas and may represent partial basal-cell differentiation. The presence and nature of a dual cell population in oncocytic neoplasms of salivary glands merit further investigation to confirm these observations.
KeywordsParotid gland Salivary gland Lipoadenoma Oncocytoma
- 2.Barnes L, Eveson JW, Reichart P, Sidransky D (2005) Tumors of the salivary glands. World Health Organization classification of tumors. Pathology and genetics head and neck. IARC Press, Lyon, pp 209–281Google Scholar
- 4.Dardick I, Kini S, Bradley G, Lee L, Leong I (2006) Salivary gland tumor cytopathology, oral and surgical pathology. Pathology Images Inc., OttawaGoogle Scholar
- 5.Ellis GL, Auclair PL (1996) Benign epithelial neoplasms. In: Rosai J, Sobin LH (eds) Tumors of the salivary glands. Atlas of tumor pathology, third series. Armed Forces Institute of Pathology, Washington, District of Columbia, pp 39–153Google Scholar