Chyloma: A Manifestation of Chyle Leak Six Months After Neck Dissection

Abstract

Chyle leaks after a neck dissection usually manifest within the immediate postoperative period. However, masked chyle leaks may present as a chyloma months later. A 54-year-old male patient with squamous cell carcinoma of the tongue underwent bilateral neck dissection, subtotal glossectomy, anterolateral thigh flap reconstruction and postoperative radiotherapy. Intraoperatively, chyle leak was encountered in level IV of the left neck. We managed it by ligation of the thoracic duct, application of Tisseel™ sealant (Baxter Inc., Illinois, USA) and one week of prophylactic fat-free feeds. Six months later, an asymptomatic chyloma of the left neck was identified on surveillance MRI. Five weeks after the diagnosis, streptococcal infection developed within the chyloma. However, initiation of fat-free diet, serial aspiration, pressure dressing and antibiotic therapy allowed the chyloma to resolve within two weeks. Further surveillance MRI over three years showed no recurrence of the chyloma. Low-volume chyle leaks may manifest as an occult chyloma. Prophylactic measures cannot replace meticulous ligation of chylous channels in left level IV neck dissection.

Keywords: chyle leak; chylocele; chyloma; chylous leakage; fat-free diet; neck dissection; streptococcus agalactiae; thoracic duct; tisseel; tongue carcinoma.

Figure 1. Arrow points to the chyloma on axial T1-weighted, gadolinium-enhanced MRI of the neck.

The chyloma was located posterolateral to the left internal jugular vein at the level of the trachea (left level IV of the neck). At this location, the thoracic duct is expected to traverse the neck before it drains into the confluence of the internal jugular and subclavian veins. The chyloma was a 3.4 x 2.2 x 1.7cm circumscribed cystic lesion that was hypointense on T1 and did not enhance with the administration of gadolinium. The rest of the neck was unremarkable.

Figure 2. Arrow points to the chyloma on axial T2-weighted, non-enhanced MRI of the neck.

The chyloma was hyperintense on T2.

Figure 3. Arrow points to the chyloma on coronal T1-weighted, non-enhanced MRI of the neck.

Together with Figure 1, this coronal view of the chyloma shows its location in left level IV of the neck where the thoracic duct is expected to be encountered during neck dissection. The chyloma appeared as a circumscribed hypointense lesion on T1.

Figure 4. Milky aspirate revealing the diagnosis of chyloma.