Lymphoepithelial carcinoma of salivary glands: CT and MR imaging findings

Abstract

Objectives: To depict the CT and MRI characteristics of salivary gland lymphoepithelial carcinoma (LEC) and provide more diagnostic information for this malignancy.

Methods: 103 salivary gland LEC subjects were retrospectively reviewed. The subjects include 35 males with a mean age of 40.8 years and 68 females with a mean age of 49.4 years. Of the 103 subjects, 86 had carcinomas in the parotid gland, 5 in the submandibular gland, 1 in the sublingual gland, 3 in the cheek and 8 in the palate. All subjects underwent routine CT and MRI (plain and contrast-enhanced scans) prior to surgical treatment and histopathological examination.

Results: Based on the pathological outcomes, all the salivary gland LECs were classified into two types from CT and MRI scans: solitary LEC (56 cases, 54.4%) and multiple LEC (47 cases, 45.6%). The latter included solitary salivary gland LEC with extraglandular lymph-node metastases (12 cases), parotid gland LEC with ipsilateral intraglandular lymph-node metastases (11 cases), parotid gland LEC with ipsilateral intra- and extraglandular lymph-node metastases (23 cases) and bilateral parotid gland LEC (1 case). The salivary gland LEC was depicted on CT and MRI scans as a lobular mass in 64 of 104 (61.5%), homogeneous mass in 65 of 104 (62.5%) or enhanced neoplasm in 94 of 104 (90.4%).

Conclusions: Salivary gland LEC has a predilection for females in the fourth to fifth decade of life and the parotid gland. CT and MRI findings between solitary and multiple salivary LECs vary. A majority of multiple parotid gland LECs are characterized by metastasis of ipsilateral intraglandular lymph nodes, which may accompany with or without extraglandular lymph-node metastases.

Keywords: computed tomography; lymphoepithelial carcinoma; magnetic resonance imaging; salivary gland.

Figure 1

Solitary LEC sited in the right buccal space (76-year-old male). Axial contrast-enhanced CT image shows a lobular and homogeneous mass with partial even and uneven margins in the right buccal space. The density of the mass is similar to that of the adjacent muscles.

Figure 2

Solitary LEC sited in the right palate (70-year-old female). Axial contrast-enhanced CT image shows a lobular mass with homogeneous enhancement in the right palate (black arrow). Right palate and upper alveolar bone resorption is also found.

Figure 3

Sublingual gland LEC (right side) with ipsilateral extraglandular lymph-node metastasis (Type 1; 42-year-old male). Axial contrast-enhanced CT image shows a lobular and homogeneous mass with partial even and uneven margins in the right sublingual gland (white arrow). An enlarged lymph node is also found in level II of the ipsilateral neck, and accompanied with adjacent internal jugular vein deformation due to the compression of this metastatic lymph node (black arrow).

Figure 4

Parotid gland LEC (left side) with ipsilateral intraparotid lymph-node metastases (Type 2; 34-year-old female). Coronal contrast-enhanced T₁ weighted image with fat suppression shows a lobular mass (black arrow) and multiple metastatic lymph nodes (white arrows) are shown in the left parotid gland. All the masses appear as homogeneous enhancement.

Figure 5

Parotid gland LEC (left side) with ipsilateral intra and extraglandular lymph-node metastases (Type 3; 43-year-old male). Coronal CT image reconstructed from axial contrast-enhanced CT images (a) and axial plain T₁ weighted image (b) show the multiple and heterogeneous masses with irregular shape and uneven margins in the left parotid gland. Also, the multiple enlarged lymph nodes with central necrosis are found in level II of the neck. Axial contrast-enhanced T₁ weighted image with fat suppression (c) demonstrates the multiple masses with heterogeneous enhancement.

Figure 6

Bilateral parotid gland LECs (Type 4; 42-year-old female). On axial contrast-enhanced CT image (a) and coronal T₂ weighted image (b), a lobular mass (right side) and a round (left side) mass with even margins are separately found in bilateral parotid glands (white arrows). Coronal contrast-enhanced T₁ weighted image with fat suppression (c) demonstrates both masses with homogeneous enhancement (white arrows). Also, on both coronal MRI images (b), the multiple, small reactive lymph nodes (black arrows), proved by pathological examination, are shown in bilateral parotid glands, respectively.