Transitional features of benign and malignant oncocytic tumors: Report of two cases

Autor: Rinaldo F. Canalis, Deborah Watson, Yao-Shi Fu
Rok vydání: 1996
Předmět:
Zdroj: American Journal of Otolaryngology. 17:335-339
ISSN: 0196-0709
DOI: 10.1016/s0196-0709(96)90021-6
Popis: (Editorial Comment: Malignant oncocytoma is rarely encountered. The authors carefully and clearly detail techniques to distinguish the more common benign oncocytoma from its malignant cousin.) Oncocytic tumors arise almost exclusively in the parotid glands of individuals over the age of 50 years and tend to occur more frequently in males. They are rare, accounting for less than 1% of all salivary gland neoplasms and usually present as an indolent, often multilobulated, solid mass in the superficial lobe of the parotid. l Although nearly always benign, an extremely rare malignant variety exists with only 30 documented cases in the world’s medical literature.2-4 Benign oncocytomas may be classified as solitary or multinodular. Approximately 7% of benign oncocytomas are bilateral.2 Histologically, they consist of large polyhedral or round cells known as oncocytes.3 Typical oncocytes have an eosinophilic, pink, granular cytoplasm and a centrally placed nucleus with prominent nucleoli. They generally do not show nuclear atypia or a high mitotic rate, even in those tumors destined to metastasize.4 Occasionally, benign oncocytomas are made up of clear cells reminiscent of elements seen in some low-grade salivary gland malignancies.’ Oncocytomas may exist in solid sheets or parallel columns, or adopt alveolar or ductlike configurations. Often, they have a variable pattern in the same tumor. In the multinodular variety, separate groups of oncocytes could undergo hyperplasia or may lose encapsulation and develop islands of tumor in an initially solitary 0ncocytoma.l
Databáze: OpenAIRE
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