Bilateral parotid tumors – metachronous metastases of clear cell renal cell carcinoma as an extremely rare differential diagnosis

Introduction Bilateral, painless tumors of the parotid gland are usually benign in nature and are primarily suggestive of a Warthin tumor. In case reports, bilateral parotid tumors are also reported in MALT lymphoma and oncocytoma, but the exact incidence hasn’t been investigated well enough. Very rarely, however, solid carcinomas may occur bilaterally. We present below a case in which bilateral parotid metastases occurred 10 years after radical nephrectomy following a diagnosis of clear cell renal cell carcinoma. Case The patient presented with bilateral preauricular and painless swellings that had been present for three months. There was no history of B-symptoms and no evidence of paraneoplastic syndrome. Clinically, palpable tumors were present in the parotid region on both sides. Sonography showed heterogeneous, intraparotid tumors with strong vascularization, one large on the right, two smaller on the left side. Elastography showed that the tumor contained 10% hardened tissue. To clarify the dignity of the lesion, we performed a needle biopsy. This showed the histological picture of bilateral metastases of clear cell renal cell carcinoma. CT staging of the neck, chest and abdomen showed no evidence of further distant metastases.

Conclusion In cases of bilateral tumors of the parotid gland, malignant causes, though very rare, must also be considered. Therefore, if a malignant tumor is suspected, a needle biopsy should be performed first to avoid a hasty, too narrow tumor resection and to guide the patient to a definitive therapy without delay.

Publication History

Article published online:
12 May 2023