Distribution of lymph node metastasis from lymphoepithelial-like carcinoma of the parotid

Abstract

Purpose: To explore the distribution of node spread from lymphoepithelial-like carcinoma (LELC) of the parotid gland based on the 2013 updated guidelines for neck node levels.

Results: 42 (58.3%) cases had metastatic nodes, all were localized at the ipsilateral neck. The detailed distribution was: level Ia 0, level Ib 6(14.3%), level II 34 (80.1%), level III 16 (38.1%), level IV 9 (21.4%), level V 7 (16.7%), level VI 0, level VII 0, level VIII 37 (88.1%), level IX 0, level Xa 2 (4.8%), and level Xb 0. Lymphadenopathy in level Ib, V and Xa was always accompanied with level II or level VIII nodal metastasis. No statistical significance was found in the incidence of nodal involvement between T1-2 and T3-4 tumors (57.4% versus 61.1%, p = 0.78).

Methods: We retrospectively reviewed the surgical and imaging documents of 72 cases of LELC from the parotid gland between January 2004 and November 2015. All patients received contrast enhanced computed tomography (CT) or magnetic resonance imaging (MRI). Parotid metastasis from nasopharyngeal cancer (NPC) was excluded. Nodal status and distribution was evaluated by both pathologic reports and imaging studies.

Conclusions: This is the first description of topography of cervical nodal metastases from LELC of the parotid gland. Incidence of nodal involvement is high. Nodes at ipsilateral level VIII and II were most frequently involved, followed by level III, IV, V and Ib. Nodes in level Ia, VI and level VII were rarely seen.

Keywords: cervical lymph nodes; lymphoepithelial-like carcinoma (LELC); parotid gland.

Figure 1. Images showing level Ib and level VIII nodes metastases in a 58 years old male patient with LELC of the left parotid gland

(A) PET panorama demonstrated multiple nodules (arrow) in the left parotid and upper neck with high uptake of FDG. (B) Coronal MRI showed multiple metastases (arrows) in and just beneath (curved arrow) the left parotid. (C and D) CT-PET suggested level Ib nodal involvement.

Figure 2. MRI showing nodal metastasis (arrow) at the surface of the right sternocleidomastoid muscle in a 51 years old male patients with LELC of the right parotid

(A) Contrast enhanced transverse T1WI MRI with fat suppression. (B) Transverse T2WI MRI. (C) Contrast enhanced coronal T1WI MRI with fat suppression.