Oral Cavity as Rare Metastatic Site for Renal Cell Carcinoma

Author: Jack Fite
Program: Resident/Clinical Fellow
Mentor(s): Benjamin Goodman, MD
Poster #: 126
Session/Time: B/3:40 p.m.

Abstract

Introduction:

Renal cell carcinoma (RCC) makes up roughly 5% of cancers in men and 3% of cancers in women, making it the sixth and tenth most common cancer in men and women, respectively. RCC is known for its late presentation, leading to a higher rate of metastases of 20-30%. Typical metastatic locations include the lungs, bones, liver, brain, and adrenal glands. Oral cavity metastases are rare, accounting for 150 reported cases of metastatic RCC as of 2020. The case demonstrates a patient with a large mass in the oral cavity that was diagnosed as metastatic RCC.

Case Information:

This patient is a 56-year-old male with history of stroke and residual expressive aphasia, who presented with a large oral cavity mass. He reported that it had been present for two months and progressively increased in size, to the point where he had difficulty speaking and swallowing. The mass originated from the bottom of the mouth, near the base of the tongue, and had grown extensively through the jaw, measuring 20 mm wide x 30 mm long (Fig 1). The mass was impressively protruding, deforming the mandible, extracting the lower incisors, and friable with minimal contact. Oral surgery was consulted for mass removal but deferred until a biopsy. Upon review of previous imaging, the patient had a CT scan one month prior, which noted multiple pulmonary nodules with the largest at 2 cm and a large left upper pole renal mass (10.1 x 8.0 x 12.4 cm). He had been scheduled for a lung nodule biopsy. At the time, the patient had only a small, pedunculated growth behind his lower teeth and was discharged with instructions to see a dental specialist.

Given this information, ENT performed a biopsy of his oral mass at the bedside on admission, offering nebulized tranexamic acid for bleeding. Urology was consulted on admission, recommending a biopsy of the lung nodule as well, which was performed by interventional radiology. Both pathology results from the oral mass and lung nodule were consistent with RCC. Radiation oncology and hematology-oncology were then consulted. Based on a 10% survival rate at 5 years, palliative options were recommended. Urology and ENT also did not recommend surgical options, due to high risk. The patient continued to tolerate a pureed diet, so a gastric tube was not pursued during his hospital course. He was discharged with plans for outpatient follow-up and palliative radiation therapy to reduce the size of the mass.

Discussion and Conclusion:

This case demonstrates a rare metastatic site for RCC. It also serves as a reminder to consider RCC metastasis in patients with known imaging concerning for renal malignancy. Unfortunately, distant metastases in RCC are often noted before the primary RCC is diagnosed, leading to poorer prognoses. Subsequent management is focused on palliative measures, to minimize pain, bleeding, and infection while prioritizing patient comfort.