Clear cell entities of the head and neck: a selective review of clear cell tumors of the salivary glands

Abstract

Clear cell changes may be observed in virtually any benign or malignant tumor of epithelial, mesenchymal, melanocytic and hematopoietic derivation not be attributed to variable etiologies. In general, benign and malignant clear cell neoplasms of the head and neck are rare. They may involve various regions and may be of diverse derivations, with only 1-2% of tumors of the salivary glands, jaws and oral mucosa are primarily or almost exclusively composed of clear cells (Maiorano et al., Semin Diagn Pathol 14:203-212, 1997). This review will selectively discuss the clinicopathological features of salivary gland tumors with clear cell changes, which, at times, may pose a diagnostic challenge and dilemma.

Keywords: Clear cell tumors; Head and neck; Salivary gland tumors.

Fig. 1

Histomorphological features of clear cell variant of oncocytoma of the parotid gland. The tumor is well demarcated and consists of monotonous clear cells, arranged in nests and organoid pattern and separated by thin fibrous spate. (Hematoxylin and eosin stain. Original magnification 20×.) (Inset: Hematoxylin and eosin stain. Original magnification 40× R. image)

Fig. 2

Clear cells in acinic cell carcinoma note the presence of serous tumor acini surrounding the clear cells. (Hematoxylin and eosin stain. Original magnification 60×)

Fig. 3

(a) Histomorphology of epimyoepithelial carcinoma of the salivary glands showing the class biphasic glandular-ductal pattern of the two cell types, inner basaloid cells and the outer clear cells, surrounded by a thickened and hyalinized connective tissue. (Hematoxylin and eosin stain. Original magnification 60×). (b) Immunohistochemistry staining of epimyoepithelial carcinoma of the salivary glands with anti-S-100 protein, showing distinct positive labeling of the outer myoepithelial cells, sparing the inner ductal cuboidal cells. (Immunohistochemistry stain. Original magnification 60×)

Fig. 4

Metastatic clear cell carcinoma to the oral soft tissues (including to the dorsal tongue area as seen in this case) is rarely seen. Note the rich sinusoidal type vascular network within the clear cell tumor. (Hematoxylin and eosin stain. Original magnification 10×/Inset = 20×)