An unusual case of latero-cervical swelling: Warthin tumor

Warthin tumor (WT) is a benign epithelial tumor of the salivary glands. It is ranked second after the pleomorphic adenoma. The tumor is characterized by the slow evolution and painlessness but without treatment, it can reach important dimensions. Optimal treatment of Warthin’s tumor is controversial, hereby we describe a case of giant Warthin tumor diagnosed in 78 year men and treated by total parotidectomy with preservation of the facial nerve.


Introduction:
Warthin's tumor (WT), also called papillary cystadenoma lymphomatosum or adenolymphoma of the parotid gland, owes this name to the American pathologist A.S. Warthin who defined it in 1929 [1]. It represents about 15 % of parotid tumor, so it occupies the second place after Pleomorphic adenoma [2]. The tumor is benign with a risk of progression to malignancy less than 1% [3]. In some cases, painlessness and slow progression allow these tumors to reach large sizes at the time of diagnosis.
This article describes a case of giant Warthin tumor of the parotid gland treated by total parotidectomy with preservation of the facial nerve.

Observation:
A 78-year -old man, came to our department, complaining of a slowgrowing mass located in the left parotid gland that has been evolving for more than 6 years. This lesion was treated by unsuccessful traditional methods. This patient had been smoking 25 cigarettes a day for 40 years. However, he has no particular medical history. Physical examination revealed a firm, mobile and painless mass measuring about 12 cm x 9 cm, occupying the left parotid and cervical region without inflammatory signs. Despite the large size of the lesion, there was no facial paralysis and no significant lymph node enlargements were noted. The MRI of the head and neck showed a voluminous pseudo cystic formation in the region of the left parotid gland. This mass slightly compresses the oropharynx and gives a voluminous left para cervical dent. It is hyperintense in T2 and hypointense in T1. The size of tumor was 115 × 90 × 70mm (figure 1). The right parotid gland is without abnormalities.  The anatomopathological examination is compatible with a Warthin tumor. The mass weighs 450grs and measured 12cm x 8,5cm x 7cm. The patient presented excellent aesthetic results, without signs of facial nerve palsy or recurrence. After one year of follow up there was any evidence of residual or recurrence.

Discussion:
Approximately 80% of salivary gland tumors affect the parotid gland. However, most of them are benign [4]. TW represents about 15 % of parotid tumor [2]. It is the most common bilateral and multicentric tumor of the parotid gland [5]. This tumor manifests especially in the fifth to seventh decades of life, mostly in males [6]. Recently, some studies have shown increased incidence in women [7]. Its etiopathogenesis is not yet well established, tobacco is the main risk factor [6,7,8]. In our case, the patient had been a long-term smoker: 25 cigarettes a day for 40 years. Clinically, TW presents as a soft, rounded and mobile tumor, which develops preferentially in the superficial lobe of the parotid gland, often at its lower pole [9]. Absence of facial paralysis and cervical lymphadenopathy leads to a benign tumor. The average size at the time of diagnosis is 36 millimeters in diameter but the size from which the warthin tumor is ranked giant is not consensual [10]. In some cases, painlessness and slow progression allow these tumors to reach large sizes at the time of diagnosis. Indeed, the cases published in the literature are rare [11]. The factors responsible for the delay in diagnosis are multiple: lack of access to care, poverty and refusal of surgery. In our case, the negligence of the patient who caused the delay in the therapeutic management thus the size of the tumor has exceeded 10cm. Ultrasonography is an exam of choice for evaluating the masses of the parotid gland. it can be associated with fine needle biopsy (FNAB) to get information about the character of the mass and to guide the therapeutic approach [12]. The Warthin tumor in MRI is very variable so the diagnostic value of the malignancy is very good but the predictive value of the diagnosis is insufficient, hence the interest of dynamic MRI [13]. In our case, the tumor is hyperintense T2 and hypointense T1. MRI and FNAB allow specifying the extension and orienting to the Benignitis Lesional but only the histopathological examination poses the diagnosis. Histological aspect is characteristic; it associates an epithelial and lymphoid contingent [14]. The therapeutic management of Warthin's tumor is controversial. It presents less than 1% risk of malignant transformation with a low rate of recurrence after surgery [3].Despite these data, the majority of authors advocate superficial parotidectomy with identification and dissection of the facial nerve [15,16]. The latter is not free from complications mainly transient or definitive facial paralysis and Frey syndrome.

Conclusion:
 Painlessness and slow progression allow these tumors to reach large sizes at the time of diagnosis  FNA and MRI significantly guide the diagnosis.