Intercalated duct lesion of the parotid

Abstract

Intercalated duct lesions of the salivary glands are rare tumors that were only recently described. However, their resemblance to other salivary gland tumors as well as their association with malignant neoplasms makes their detection, treatment, and follow-up paramount. We present the case of a 63-year-old woman diagnosed with an intercalated duct lesion of the parotid. Her case is illustrative of the difficulty and importance of an accurate pathologic diagnosis in the management of patients with these lesions.

Fig. 1

Axial CT image demonstrating a 5 mm left parotid gland node (arrow) deep to the skin marker with surrounding fat stranding

Fig. 2

Low magnification view showing a proliferation of small ducts and lacking a well-defined fibrous capsule (H&E, ×100)

Fig. 3

The tubules are composed of a single layer of small, cytologically bland luminal ductal cells with inconspicuous abluminal myoepithelial cells (H&E, a ×400, b ×1,000)

Fig. 4

Immunohistochemical staining for calponin highlights an abluminal myoepithelial layer surrounding each small duct (×400)