Metachronous bilateral metastases of renal cell carcinoma to the parotid region

Differential Diagnosis between Oral Metastasis of Renal Cell Carcinoma and Salivary Gland Cancer

Renal cell carcinoma, which has clear cells in 70% of cases, has a high frequency of hematogenous distant metastases to lung, bone, liver, and other areas. Metastatic cancer accounts for 1 to 3% of malignant tumors in the stomatognathic region, and the metastasis of renal cell carcinoma to the oral mucosal tissue, though extremely rare, does occur. In addition, clear cells have been observed in some salivary gland cancers in the oral cavity. Therefore, the differential diagnosis of metastatic renal cell carcinoma and salivary gland cancer is important. This review discusses the differential diagnosis between metastatic renal cell carcinoma and malignant tumors of the salivary gland.

Metastatic renal cell carcinoma, clear cell type, of the parotid gland: a case report, review of literature, and proposed algorithmic approach to salivary gland clear cell neoplasms in fine-needle aspiration biopsies

Renal cell carcinoma (RCC), clear cell type, is a commonly encountered metastatic tumor that can present at unusual anatomic sites many years after the primary tumor resection. Noncutaneous metastasis to the parotid gland is unusual; however, a number of cases of parotid RCC metastasis have been reported. Fine-needle aspiration biopsy (FNAB) is regularly utilized during the evaluation of salivary gland lesions, where it has a high sensitivity, specificity, and accuracy; however, the identification and definitive diagnosis of primary and metastatic clear cell neoplasms is a potential diagnostic pitfall for salivary gland FNAB. Here, we describe a case of RCC, clear cell type, metastatic to the parotid gland that was diagnosed entirely from FNAB cell block material, which is the first such reported case to our knowledge. We review the literature for cases of parotid RCC metastasis and focus on the utility of FNAB for synchronous versus metachronous presentations. Finally, we evaluate the differential diagnosis of clear cell parotid lesions, including ancillary histologic studies, and propose an algorithmic approach to clear cell neoplasms of the salivary gland.

Metastatic tumors to the oral and maxillofacial region: a retrospective study of 19 cases in West China and review of the Chinese and English literature

PURPOSE

The aim of this article was to obtain an overview of metastatic tumors to the oral and maxillofacial (OMF) region, especially the differences in the constituent ratios of primary cancers between the United States and China.

PATIENTS AND METHODS

Clinical findings of 19 cases encountered in West China Hospital of Stomatology were summarized and the English and Chinese literature were reviewed and analyzed. The main clinical features of OMF metastases were summarized, with an emphasis on primary cancers' constituents.

RESULTS

The lung, breast, kidney, liver, and prostate were the top 5 common primary sites of cancer. However, there was a significant difference in the primary cancers' constituents between United States and China (P < .001). The breast, kidney, prostate cancers, and melanoma of skin were more frequent primary cancers in United States than in China, whereas that of the lung, thyroid, liver, esophagus, and the stomach were more common in China than in United States. The proportions of the OMF metastatic lesions originating in the lung, kidney, liver, thyroid, and esophagus in all OMF metastatic tumors were higher than the corresponding primary cancers' prevalent proportions.

CONCLUSIONS

The frequency of developing OMF metastasis is not always consistent with primary cancers' prevalence, which suggests that different cancers have different potentiality to develop OMF metastasis. Cancers of the kidney, liver, lung, thyroid, and esophagus were more likely to spread to the OMF region. In general screening of primary cancer, it would be helpful to take into account the metastatic potentiality of different cancers and primary cancers' prevalence in different countries in the case of occult primary.

Histopathological findings in parotid gland metastases from renal cell carcinoma

Metastatic tumours involving the parotid gland arising from non-head and neck origin are rare. Immunohistochemistry has improved the differential diagnosis of these lesions. Current immunohistochemical markers allow the distinction between a number of potential primary tumours (e.g., lung, kidney and breast). We present the clinical and histomorphological features of three renal cell carcinoma (RCC) patients presenting with a parotid mass, review the literature of various non-head and neck malignancies metastasizing to the parotid gland, and discuss their differential diagnosis. Two females and one male, aged 58 to 76 years, presented with a parotid tumour of renal cell origin. In one case, the parotid mass was the first clinical manifestation. In the two other cases, a nephrectomy had been performed 5-9 years earlier because of RCC. The cases showed a highly vascular parotid lesion causing difficulty in interpretation of the fine needle aspirate. Two patients underwent a superficial parotidectomy and one patient an open biopsy of the parotid gland tumour. Immunohistochemical stainings for vimentin, CD10 and PNRA were positive suggesting renal cell origin, which was later confirmed. Clinical and radiological evaluations and diagnosis by fine needle aspiration may prove difficult partly due to the vascular nature of parotid metastasis of renal cell carcinoma. Immunohistochemical staining is useful in identifying the primary tumour.

Late metastasis of renal cell carcinoma to the submaxillary gland 10 years after radical nephrectomy

Renal cell carcinoma metastasis to the submaxillary gland after tumor nephrectomy has not been previously recorded in the literature. Most reported cases have involved the parotid gland. We report in this article the first case of solitary submaxillary gland metastasis from clear cell renal cell carcinoma in an 83-year-old man who presented 10 years after primary treatment. The submaxillary gland was excised with preservation of the facial nerve.

Bilateral parotid voluminous masses: a case report

The case of a 75-year-old woman with voluminous bilateral symmetrical masses of the parotid glands is reported, and the literature relevant to the differential diagnosis in bilateral neoplastic and nonneoplastic parotid masses is reviewed. The presurgical workup was based on clinical evaluations, nuclear magnetic resonance imaging findings, and cytologic examination to obtain the differential diagnosis. Benign or malignant tumors were excluded. Surgery was performed for esthetic reasons and in consideration of progressive enlargement of lesions. Histopathologic examination of resected masses revealed benign lymphoepithelial cysts with polyclonal infiltration of lymphoid cells. Serological testing for tuberculosis, cytomegalovirus, human immunodeficiency virus, and Epstein-Barr virus (EBV) and testing using the in situ hybridization technique for the presence of cytomegalovirus and EBV were negative for productive infection or viral replication. A diagnosis of retention cysts was suspected on the basis of presurgical evaluation, histopathological examination, and serologic analysis. In this case, bilateral obstruction of the parotid ducts by a mobile denture probably played the main role in the pathogenesis and development of bilateral parotid retention cysts, because any other specific cause for the pathogenesis was not found with diagnostic tools.