|Year : 2022 | Volume
| Issue : 1 | Page : 156-158
A deep lobe parotid tumor tending the facial nerve and its branches
Nisha Muruganidhi1, Mariappan Rajagopal2, Santhanakrishnan Kaliavaradan2, Poornima S Bhat2
1 Departments of ENT and and Head and Neck Surgery, Puducherry, India
2 Sri Manakula Vinayagar Medical College and Hospital, Madagadipet, Puducherry, India
|Date of Submission||05-Mar-2021|
|Date of Decision||20-May-2021|
|Date of Acceptance||07-Jun-2021|
|Date of Web Publication||27-Jun-2022|
Dr. Nisha Muruganidhi
Department of ENT, Sri Manakula Vinayagar Medical College and Hospital, Madagadipet, Puducherry - 605 107
Source of Support: None, Conflict of Interest: None
Benign tumors of major salivary glands commonly affect the parotid gland and it is rare when the tumor exclusively involves the deep lobe of the gland. The mainstay of treatment is surgical excision. Parotid surgeries carry a formidable risk of injury to the facial nerve. Hence, identification of extracranial part of facial nerve using many of its anatomical landmarks helps in preventing this daunting complication. There are instances where the facial nerve's morphometry is altered due to the location and extent of the tumor. A better knowledge of the anatomy and anticipation for these variations can result in a better outcome limiting the complications of the surgery.
Keywords: Benign tumor, deep lobe, facial nerve, parotid, pleomorphic adenoma, salivary gland
|How to cite this article:|
Muruganidhi N, Rajagopal M, Kaliavaradan S, Bhat PS. A deep lobe parotid tumor tending the facial nerve and its branches. BLDE Univ J Health Sci 2022;7:156-8
|How to cite this URL:|
Muruganidhi N, Rajagopal M, Kaliavaradan S, Bhat PS. A deep lobe parotid tumor tending the facial nerve and its branches. BLDE Univ J Health Sci [serial online] 2022 [cited 2022 Aug 16];7:156-8. Available from: https://www.bldeujournalhs.in/text.asp?2022/7/1/156/348267
Primary tumors in the parotids are rare and they constitute only 1%–3% of head-and-neck tumors. It most commonly involves the superficial lobe and is mostly benign. The incidence of parotid tumors affecting exclusively the deep lobe is 10%–12%. The prime aim is complete removal of the disease with preservation of the facial nerve. The stretching of the main trunk of the facial nerve and its branches in this patient by the tumor made the surgery challenging, and a deep lobe parotidectomy was done in this case with preservation of the facial nerve.
| Case Report|| |
A 35-year-old male presented to the department of Otorhinolaryngology of a tertiary care center with complaints of swelling in the right parotid region for the past 4 years that was insidious in onset, gradually progressive in size, not associated with pain. Complete ENT and head-and-neck examination were done which revealed a well-defined mass of size approximately 4 cm × 3 cm right parotid region with smooth surface, nontender, and mobile. Bilateral facial nerve was intact. Oropharynx was normal with no bulge or medial displacement of tonsil and lateral pharyngeal wall.
Ultrasonography of the neck showed a well-defined lobulated hypoechoic, heterogenous lesion of size 3.8 cm × 1.9 cm suggestive of likely deep lobe pleomorphic adenoma. Fine-needle aspiration of the right parotid gland showed moderate cellularity with loosely cohesive clusters, sheets of ductal epithelium, and scattered myoepithelial cells, features suggestive of pleomorphic adenoma.
After obtaining written informed consent, right side deep lobe parotidectomy was performed under general anesthesia. Intraoperatively, the main trunk of the facial nerve was identified and preserved using tragal pointer (TP) and posterior belly digastric muscle as landmarks. The tumor was occupying the deep lobe exclusively. The superficial lobe was free of lesions. The tumor was tending the facial nerve in such a way that the nerve was pushed laterally and it was at the level of the TP [Figure 1]. The main trunk of the facial nerve was stretched, and its distance from the stylomastoid foramen (SMF) was measured using cotton thread and was found to be 22 mm [Figure 2]. Deep lobe parotidectomy was done, and the facial nerve along with its branches was preserved. The excised specimen was sent for histopathological examination and suggestive of pleomorphic adenoma [Figure 3].
|Figure 1: Deep lobe tumor tending the main trunk of the facial nerve and pushing it laterally|
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|Figure 2: The distance between the stylomastoid foramen and main trunk of facial nerve measured using cotton thread|
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| Discussion|| |
Pleomorphic adenomas are most common benign tumors of the salivary glands, often involving the superficial lobe of parotid gland. They have a multifocal pattern with high chance of recurrence with a tendency for malignant transformation.
During parotidectomies, the facial nerve is to be dealt with care and precision to avoid the formidable complications. The nerve can be identified using many anatomical landmarks, the most commonly used are SMF, TP, posterior belly of digastric (PBD), and tympanomastoid suture.
In a study by Pather and Osman, the distance between SMF and main trunk is about 14 mm. In our case, the main trunk was stretched over the tumor which may be the plausible explanation for the increase in the distance of main trunk of facial nerve (FNT) from SMF till its bifurcation to be 22 mm. The distance between TP and FNT is 6–14 mm, FNT and PBD are 5–11 mm, whereas in this case, the nerve was almost at the level of the tragal pointer.
Although there were variations in the position of facial nerve from its anatomical landmarks, the nerve was preserved. Deep lobe parotidectomy done and the tumor was delivered in between the stretched cervicofacial branches of the facial nerve.
| Conclusion|| |
The most vital part of performing a parotid surgery is the precise understanding of the morphology and morphometry of the facial nerve and the anticipation of the variations. This case highlights the fact that even when there is a disproportionate stretching of facial nerve, the nerve was preserved. Furthermore, the tumor exclusively involved the deep lobe, and hence, the superficial lobe was spared and a deep lobe parotidectomy was performed with a facial nerve preservation which allows for a better outcome.
We thank the department of Pathology, Department of Anaesthesia and our OT nursing staff for their support.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3]