A miscellany of cribriform pattern, squamous metaplasia and clear cells in pleomorphic adenoma of upper lip: A diagnostic paradox

Abstract

Pleomorphic Adenoma (PA), a benign neoplasm of glandular origin most commonly involves major salivary glands. It is rare in minor salivary glands such as hard palate, upper lip and buccal mucosa, frequently affecting middle aged females. PA comprises diverse histopathologic features of epithelial, myoepithelial and mesenchymal components. Aberrant histopathologic features in Pleomorhic Adenoma thus calls for judicious discrimination from alike entities which facilitates appropriate surgical management. Here we present a case report of PA in upper lip in a 25 year old female patient showing uncommon findings like clear cells, squamous metaplasia and cribriform pattern.

Keywords: Clear cell; cribriform pattern; pleomorphic adenoma; squamous metaplasia; upper lip.

Figure 1

Extraoral photograph showing diffuse swelling above the upper lip region on the right side

Figure 2

Intraoral photograph showing nodular mass on the upper labial mucosa

Figure 3

Encapsulated gross-specimen measuring 1.5 cm × 2.0 cm × 1.0 cm with glistening homogeneous tan white cut surfaces

Figure 4

H&E-stained section (×10) showing well-circumscribed mass surrounded by fibrous capsule and glandular epithelial cells with numerous cystic spaces in the stroma

Figure 5

Photomicrograph (H&E stained, ×40) showing ducts lined by luminal cuboidal cells and abluminal myoepithelial cells

Figure 6

Photomicrograph showing periodic acid-Schiff (×40) positive mucinous material

Figure 7

Photomicrograph (H&E stained, ×40) showing myxomatous change of the stromal component

Figure 8

Photomicrograph (×40) showing hyalinized, dense collagen fibers in the connective tissue

Figure 9

Photomicrograph (H&E, ×40) showing keratin pearl (squamous metaplasia) in the stroma

Figure 10

Photomicrograph (×40) showing clear cells along with proliferating myoepithelial cells