10.3\ Parotidectomy

10.3.1  Discussion

Parotidectomy is most commonly performed for primary salivary neoplasm resection, but is also performed for oncologic management of skin cancers. Several types of parotidectomy can be implemented, including superficial parotidectomy and total parotidectomy with or without facial nerve preservation, depending on the type, size, and location of the tumor (Figs. 10.29, 10.30, and 10.31). The defects created by more extensive resections can be reconstructed using tissue flaps or synthetic materials. Furthermore, when the facial nerve is compromised, eyelid weights are often used to aid eye closure.

In general, complications and expected consequences related to parotidectomy may include

cosmetic deformity, facial nerve deficits, sialocele, wound infection, hematoma, and tumor recurrence. In particular, recurrence of parotid pleomorphic adenoma has an incidence of 1–5% and most commonly occurs within the first 10 years following surgical resection. Recurrent lesions have fairly characteristic imaging features. On T2-weighted MRI, the majority of recurrent tumors have very high signal intensity due to myxoid contents. The presence of multiple subcentimeter nodules is a strong indicator of recurrence and is observed in about two-thirds of cases. This feature results in a “bunch of grapes” appearance (Fig. 10.32). Recurrent pleomorphic adenomas are sometimes located in the subcutaneous tissues or adjacent neck spaces perhaps due to spillage during surgery. The enhancement pattern is variable, depending upon the extent of cystic components, fibrosis, and necrosis.

Fig. 10.29  Superficial parotidectomy with graft reconstruction. Axial CT image shows fat graft occupying the expected location of the right superficial parotid lobe (arrowhead). The deep lobe of the right parotid gland remains intact (arrow)

Fig. 10.30  Total parotidectomy. Axial T2-weighted MRI shows the absence of the left parotid gland, resulting in concavity of the overlying skin. The facial nerve could be spared along with the retromandibular vein, and the contralateral normal parotid gland is intact

Fig. 10.31  Total parotidectomy with facial nerve sacrifice. Axial T1-weighted MRI (a) shows the absence of the left parotid gland and atrophy of the left facial muscles. Partial resection of the left masticator muscles and man-

Fig. 10.32  Recurrent parotid pleomorphic adenoma. Coronal STIR MRI demonstrates a cluster of nodules with a “bunch of grapes” appearance (arrow)

dibular ramus was also performed. The axial CT image (b) shows a left eyelid weight (arrow), with considerable metal streak artifact

10.4\ Salivary Duct Stenting

and Endoscopic Stone

Removal

10.4.1  Discussion

Salivary duct stones can be managed by sialendoscopic extraction. Sometimes, plastic stents are inserted after stone removal in order to reduce the risk of subsequent stenosis (Fig. 10.33). These

a

b

appear as tubular hyperattenuating structures on CT and should not be misinterpreted as residual sialolithiasis. Occasionally, stone extraction can be complicated by sialocele or even cutaneous fistula formation due to the friability of the inflamed tissues in the setting of acute sialadenitis and sialodacryoadenitis. In such cases, imaging­ can be performed to assess for the extent of associated fluid collections and sinus tracts (Fig. 10.34).

Fig. 10.34  Parotid cutaneous fistula after endoscopic stone extraction. Axial T1-weighted MRI shows a right face skin defect and sinus tract (arrow) extending to the underlying parotid gland