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

Metastases to the parotid glands: An institutional experience

BACKGROUND

Metastatic lesions to the salivary gland are rare and mostly affect the parotids. Metastases represent 8% of all malignant lesions of the parotid gland. Around 80% originate from squamous cell carcinomas (SCC) of the head and neck region. Fine needle aspiration (FNA) plays a crucial role in distinguishing primary salivary gland lesions from metastases. Herein we describe our series of metastases to the parotid glands.

MATERIALS AND METHODS

We analysed 630 parotid gland FNAs over a decade including conventional and liquid-based cytology specimens. Ancillary techniques such as immunocytochemistry (ICC) were conducted on cell blocks.

RESULTS

Eighty (12.4%) cases were malignant lesions, of which 53 (63.75%) were metastases including 24% melanoma, 22.6% SCC, 19% renal carcinomas, 7.5% breast carcinomas, 11.3% lung, 9% intestinal and 1.8% testicular, malignant solitary fibrous tumour and Merkel cell carcinoma. The 53 cases, classified according to the Milan system for salivary cytopathology, belonged to 5 Suspicious for malignancy (SFM) and 48 malignant (M) categories. Forty had a known history of primary malignancy (75.4%), while 13 were suspicious to be a metastatic localisation (24.5%), distributed as 5SFM (2SCC and 3Melanoma) and 8 M. A combination of clinical history, cytomorphology and ICC identified 100% of them.

CONCLUSIONS

Fine needle aspiration plays a central role in the diagnostic workup of patients with metastatic lesions to their parotid glands, thereby defining the correct management. Diagnostic accuracy may be enhanced by applying ICC. Although melanoma and SCC are the most common histological types, several other malignancies may also metastasize to the parotid glands and should be kept into consideration.

Renal Cell Carcinoma Metastasizing to Oral Soft Tissues: Systematic Review

Background  Renal cancer metastasis to oral region is very rare. Studies have been published analyzing the cases of metastatic tumors to the oral cavity by many researchers. Very few research studies have been conducted till date to analyze the renal cancer metastasis as the sole primary source to the oral soft tissues. The goal of this study was to examine the published cases of oral soft tissue metastasis from renal cell carcinoma as the only primary source from 1911 to 2022. Materials and Methods  An electronic search of the published literature was performed without publication year limitation in PubMed/Medline, Scopus, Google Scholar, Web of Science, Science Direct, Embase, and Research Gate databases, using mesh keywords like ("Renal cancer," or "Renal carcinoma" or "Renal cell cancer" or "Renal cell carcinoma"), and ("Metastasis" or "Metastases"), and ("Oral soft tissues" or "Tongue" or "Palate" or "Tonsil" or "Buccal mucosa" or "Salivary glands"). We also searched related journals manually and the reference lists. Results  Our research revealed a total of 226 relevant articles with 250 patients. Parotid glands and tongue were the most common sites of metastasis. 23% patients died with a survival time of 10 days to 4 years. Conclusions  Oral soft tissue metastasis from renal cell carcinoma has a bad prognosis. More cases need to be published in order to raise awareness of these lesions.

Renal cell carcinoma metastasizing to salivary glands: Systematic review

Distant metastasis to salivary glands is a very rare event. Renal cell carcinoma (RCC) has been known for its high propensity of metastasis to unusual locations and salivary glands are one among those sites. Approximately 0.1% of all salivary gland metastatic neoplasms originate from renal malignancies Literature has reported several studies analysing the metastatic tumors to the oral region. However, very little research work has been published to date to analyse solely the RCC metastasizing to the salivary glands. Thus, this review was conducted to examine the published cases of RCC metastasizing to salivary glands in the literature to date and to learn about their characteristics. An electronic search of the published literature was performed without publication year limitation in PubMed/ Medline, Scopus, Google Scholar, Web of Science, Science Direct, Embase, and Research Gate databases, using mesh keywords like ('Renal cancer', OR 'Renal carcinoma' OR 'Renal cell cancer' OR 'Renal cell carcinoma'), AND ('Metastasis' OR 'Metastases'), And ('Salivary glands' OR 'Parotid gland' OR 'Submandibular gland' OR 'Sublingual gland'). We also searched all related journals manually. The reference list of all articles was also checked. Our research revealed a total of 83 relevant papers (1965-2022) with 100 patients. Parotid was the most predominant gland affected. 8% of patients died with a mean survival time of 1.3 yr. From this research, it can be concluded that RCC metastasizing to salivary glands is a rare occurrence. Careful evaluation of these cases is needed in order to raise awareness of these lesions and gain a better understanding of their characteristics for clinical as well as global implications.

Use of Immune Checkpoint Inhibitors in Elderly Patients With Chronic Kidney Disease and Renal Cell Carcinoma Metastasis of the Parotid Gland: Case Report and Review of the Literature

Renal cell carcinoma metastasis of the parotid gland is extremely rare, and the present literature review found only 23 cases reported in the last two decades. We present a case of a 75-year-old woman with a colon cancer history who had parotid gland metastasis as the first manifestation of second primary kidney cancer. The presence of multiple comorbidities affected medical decision-making. Therefore the patient was treated primarily with immunotherapy. After four cycles of dual immune checkpoint blockade, this advanced patient still benefited and was changed to nivolumab monotherapy as maintenance therapy.

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.

Rare Case of Clear Cell Renal Cell Carcinoma Metastasizing to Contralateral Kidney and Ipsilateral Parotid more than five Years following Nephrectomy

Backgroung/Aim: Salivary gland malignancies are rare, with only a fraction due to metastases. We report a rare case of the Clear Cell Renal Cell Carcinoma (CCRCC), a subtype of the Renal Cell Carcinoma (RCC), metastasizing to the parotid gland more than five years following nephrectomy.

Case report: A 75-year-old female presented with a unilateral left parotid mass that was growing over the period of 18 months. After clinical and laboratory examinations, the patient underwent left partial superficial parotidectomy with preservation of the facial nerve. The significance of the patient’s history of the CCRCC was pivotal to the histopathological diagnosis of a metastatic CCRCC to the parotid.

Conclusions: The unpredictable nature of the RCC results in the need for a long period of follow-up, as well as having a high degree of suspicion of metastasis in a patient presenting with a medical history of the RCC and a parotid mass.

Metastatic clear cell renal carcinoma to the auricular region disguised as a vascular thrombus: Case report

In about 25-30% of patients with primary renal cell carcinoma, metastasis is not uncommon and usually does not give rise to difficulties in diagnosis. However, its presentation as a subcutaneous mass following an elapse of several years after the initial diagnosis is not only uncommon but may be also mistaken for a thrombus in imaging studies due to its common high vascularization. We present here a case of a 70-year-old woman with an oncologic history of renal cell carcinoma who noticed after five years a mass in the auricular region radiologically suggestive of a vascular thrombus. Fine-needle aspiration cytology showed malignant epithelial cells compatible with metastasis of renal clear cell carcinoma, supported by immunohistochemistry performed on the cell block. This rather uncommon presentation and precise diagnosis by fine-needle aspiration prompted us to report the case, emphasizing the role of cytopathology as a useful, fast and minimally invasive method for clarifying the neoplastic nature of highly vascularized lesions.

Metastases to Both Parotid Glands Six and Twelve Years after Resection of Renal Cell Carcinoma

Metastases of renal cell carcinoma (RCC) involving the parotid gland are very rare. We present to our knowledge the first case of a 74-year-old woman with metastases of an RCC which affected both parotid glands six and twelve years following curative therapy.

Applications of molecular testing in surgical pathology of the head and neck

Molecular testing in routine surgical pathology is becoming an important component of the workup of many different types of tumors. In fact, in some organ systems, guidelines now suggest that the standard of care is to obtain specific molecular panels for tumor classification and/or therapeutic planning. In the head and neck, clinically applicable molecular tests are not as abundant as in other organ systems. Most current head and neck biomarkers are utilized for diagnosis rather than as companion diagnostic tests to predict therapeutic response. As the number of potential molecular biomarker assays increases and cost pressures escalate, the pathologist must be able to navigate the molecular testing pathways. This review explores scenarios in which molecular testing might be beneficial and cost-effective in head and neck pathology.

Diagnosis of Metastatic Renal Cell Carcinoma on Fine-Needle Aspiration Cytology

Fine-needle aspiration has assumed an increasingly important role in the diagnosis and management of patients with advanced stage cancer. Given its predilection for metastases to distant sites and organs at the time of presentation, metastatic renal cell carcinoma (RCC) is not infrequently encountered in the setting of fine-needle aspiration for initial diagnosis. In some instances, fine-needle aspiration may be the only opportunity to obtain diagnostic tissue to diagnose and subclassify RCC. Therefore, cytopathologists and cytotechnologists should be familiar with and recognize the cytomorphology of RCC and the ancillary studies that can be used to confirm and subclassify RCC. Herein, we describe a case of metastatic RCC initially diagnosed on fine-needle aspiration, discuss the cytomorphologic features of RCC subtypes, and review pertinent ancillary immunohistochemical and cytogenetic adjuncts.