Renal Cell Carcinoma Presenting as Bulky Parotid Mass—a Case Report and Review of Literature

Abstract

Renal cell carcinoma is the third most common malignancy to metastasize to the head and neck region. Among them, parotid is a well-reported site, although limited to case reports. Tumours with predominance of clear cells found in the head and neck, namely oncocytoma, clear cell carcinoma, acinic cell carcinoma, mucoepidermoid carcinoma and epithelial-myoepithelial carcinoma should be distinguished from clear cell renal cell carcinoma. This case report is regarding a patient with renal cell carcinoma presenting as bulky parotid metastasis. This literature review is to reiterate the possibility of renal cell carcinoma with parotid metastasis, as to aid in good science and better practice.

Introduction

Renal cell carcinoma (RCC) represents 3% of all adult malignancies [1]. Metastatic parotid lesions are, by itself, rare. Here, we present a 63-year-old man who was evaluated for a huge parotid swelling which subsequently turned out to be metastatic from RCC.

Case History

A 63-year-old gentleman, a former smoker, with no comorbidities, presented with left parotid swelling of 2-year duration, which rapidly grew in size over the past 8 months, and a 1-month-old left thigh swelling. There were no restrictions of eye movements/ear ache/dryness of mouth/dysphagia/history of trauma. No history of fever, weight loss or other systemic symptoms could be elicited. He presented to us as the facial swelling had increased in size and had caused cosmetic concerns.

At presentation, his Eastern Co-operative Group Performance Status was 3, with stable hemodynamic status. There was a 12 × 12 × 10 cm firm, mobile, non-erythematous swelling over left parotid, extending from zygomatic arch superiorly to mandible inferiorly, with overlying dilated veins and an auscultatory bruit. A 22 × 18 cm, hard circumferential swelling was seen in the left thigh. Ear, nose, throat, left facial nerve and other systemic examinations were unremarkable. The possibility of a parotid gland tumour with probable bone metastasis was considered.

His hemogram and organ function tests were normal. Computed tomography (CT) scan of the head showed a heterogeneously enhancing 8.3 × 7.3 cm lesion in the left parotid, lateral to the retromandibular vein and a similar lesion within the right maxillary sinus with a cortical break (Fig. 1a). CT chest showed lung metastasis and mediastinal nodes. On CT abdomen, there was a heterogeneously enhancing 3.7 × 3.3 cm mass lesion in the upper pole of the left kidney, with renal vein invasion, suggestive of RCC, and left adrenal deposit (Fig. 1b). Abnormal uptake in the left femur shaft was seen on bone scan. Biopsy of the parotid mass showed polygonal cells with clear/oncocytic cytoplasm in lobular nests and sheets supported by a delicate vascular network and immunohistochemical (IHC) staining was positive for CK & CD10 and negative for DOG-1, CK-7&20, suggestive of metastatic RCC, with clear cell and oncocytic morphology, to parotid mass (Fig. 1c–f). Both radiological and histopathological features suggested metastatic RCC and as the patient was sick with poor general condition, renal biopsy was deferred.

Fig. 1.

a Computed tomography (CT) head showing 8.3 × 7.3 cm heterogenous mass in the left parotid region. b CT abdomen showing a 3.3 × 3.7 cm heterogenous mass in the upper pole of left kidney. c HE × 400 section showing nests and lobules of epithelial cells with moderate to abundant eosinophilic cytoplasm resembling oncocytic cells with intervening vascular network. d HE × 400 section showing nest and sheets of epithelial cells with clear cytoplasm with intervening thin-walled vessels in the stroma. e CK diffuse strong positive. f CD 10 diffuse strong positive

After multidisciplinary tumour board discussion, the patient was assigned the diagnosis of metastatic renal cell carcinoma, poor-risk, with lung, adrenal, bone, nodal, maxillary sinus and bulky parotid metastasis. He was started on bisphosphonates and pazopanib 800 mg once daily due to financial constraints. He has stable disease at 8 months of treatment.

Discussion

RCC constitute 3% of all adult malignancies and one-quarter of them present with advanced or metastatic disease [1, 2]. Comonest metastatic sites are lungs (76%), bones(42%) and liver (41%) [3]. By virtue of the unpredictable metastatic potential of RCC, its synonyms like internist’s/physician’s cancer are aptly justified. RCC ranks third among the infraclavicular cancers to metastasise to the head and neck [1]. Approximately, 15% of RCC throw distant metastasis to the head and neck, the most common site being the thyroid gland followed by cervical lymphatics, mandible, sinonasal tract, and skin of the face and scalp [1, 4]. Generally, 30% of parotid swellings are malignant, among which, metastatic lesions constitute only 5–25% [5]. Primary sites of cancer which metastasise to the parotid are mostly cutaneous malignancies of the head and neck region [6]. Among the infraclavicular primaries, the most common site is the lung, followed by renal, breast and colon [5]. The hypervascular nature of RCC with multiple arteriovenous shunts, the tumour cells’ ability to detach from the primary site and its spread via Batson’s plexus and lymphatics allow homing of the disease into any organ. RCC metastasis may precede or succeed the primary diagnosis by a variable amount of time [5].

Our patient is a male smoker, whose primary tumour was asymptomatic till he presented with huge parotid mass and bone metastasis. The long-standing history of parotid mass may be explained by the indolent nature of some RCC and is substantiated by the watchful wait policy practiced in oligometastatic disease. Radiological features need not always differentiate primary from metastatic parotid tumour. The close differentials to be remembered are clear cell carcinoma of the salivary gland, mucoepidermoid carcinoma, acinic cell carcinoma, oncocytoma and epithelial-myoepithelial carcinoma; all of which could be excluded by detailed histopathological examination including IHC [7]. Another clinical diagnosis in this case is co-existence of parotid oncocytoma. Uniformly, negative CK7 and CK20 and diffuse uniform positive CD10 support tumour origin in the kidney, rather than RCC with primary salivary gland tumour (dual tumours). Almost all/most of the salivary gland tumours are CK7 positive which is not seen in our case. Salivary neoplastic myoepithelial cells have been reported to gain CD10 expression in relation to their normal counterparts. However, the gain of this protein is not a sensitive marker for detecting myoepithelial cells in the majority of the tumours, except for epithelial myoepithelial carcinoma (EMEC); however, EMECs are CK 7 positive. Moreover, bone metastasis favoured RCC, which can have clear cell and oncocytic pattern as well. Table 1 represents the relevant details of RCC patients with parotid metastasis reported in the literature from 2000 till date.

Table 1.

Relevant details of RCC patients with parotid metastasis reported in the literature from 2000 to date

Author/year of publication	No. of cases	Patient’s age/sex	Time frame from RCC diagnosis (m)	Other metastatic sites	Subsequent treatment received	Survival as reported	Available at
S. Kundu et al. (2001)	1	61/M	0	Bone, skin, lung, brain	Palliation	NR	https://doi.org/10.1258/0022215011908009
Lei Li et al. (2001)	1	63/M	120	Nil	Parotidectomy, IL-2	Alive at 7 years	https://doi.org/10.1053/joms.2001.21894
Youn W. Park et al. (2002)	1	83/F	120	Nil	Superficial parotidectomy	Disease free at 1-year follow-up	https://doi.org/10.1097/00005537-200203000-00009
Gogus et al. (2004)	1	59/F	120	Nil	Superficial parotidectomy	18 m	https://doi.org/10.1111/j.1442-2042.2004.00902.x
Beatriz Patino Seijas et al. (2005)	1	67/M	0	Nil	Superficial parotidectomy, Nephrectomy	24 m	https://doi.org/10.1016/j.tripleo.2004.08.007
Pomar Blanco et al. (2006)	1	NR	NR	NR	NR	NR	https://doi.org/10.1016/s0001-6519(06)78662-9
Hsiang-Che Huang et al. (2006)	1	56/F	36	Bone, mediastinal mass	Parotidectomy	No progression at 8 months
Andreadis et al. (2007)	2	NR	NR (Pt1) / 120 (Pt2)	NR	NR	NR	http://www.webio.hu/por/2007/13/2/0161
Mustafa Kaplan et al. (2008)	1	68/M	0	Nil	Radical nephrectomy, RT to parotid, IFN ά	2 months	Am J Case Rep 2008; 9:316–320, ID: 864067
Spreafico et al. (2008)	1	69/M	18	Nil	Parotidectomy, RT	NR	PMCID: PMC2689528 PMID: 19186459
Roderik Mrena et al. (2008)	3	58/F 76/F 62/M	0 108 60	Nil Nil Nil	Superficial parotidectomy NR Superficial parotidectomy	NR NR NR	https://doi.org/10.1007/s00405-008-0679-8
M Wayne et al. (2010)	1	61/F	-, no renal primary	Skin, pancreas	Superficial parotidectomy	NED at last follow-up	https://doi.org/10.1186/1477-7819-8-18
Rahul Janak Sinha et al. (2011)	1	35 M	0	NR	NR	NR	https://doi.org/10.5430/jst.v1n3p150
Chai Yanlan et al. (2012)	1	44/F	0	Liver, bone, lung	IL-2, bisphosphonates, RT, Sunitinib	On follow-up	https://doi.org/10.3892/ol.2013.1110
Claire M. Lawlor et al. (2012)	1	71/M	60	Pancreatic lesions	Total parotidectomy	Disease free at 1 year	https://doi.org/10.7243/2049-7962-1-15
Robert Deeb et al. (2012)	1	82/M	240	NR (history of CLL also)	Total parotidectomy, RT, palliative chemotherapy	NR	https://doi.org/10.1155/2012/265708
Pejman Maralani et al. (2014)	1	64/F	0	Thyroid, Submandiular gland	Nephrectomy, partial parotidectomy, Sunitinib	Stable disease at 1-year follow-up	https://doi.org/10.1159/000362247
Jia-li shi et al. (2014)	1	56/F	72	Thyroid	Superficial parotidectomy	NED at 2 years	https://doi.org/10.3892/ol.2015.3549
Aaron M. Udager et al. (2014)	1	64/M	72	Lung	Sunitinib	NR	https://doi.org/10.1002/dc.23103
Achim M. Franzen (2015)	1	74/F	72	Nil (treated for colon cancer also)	Parotidectomy	Remission at 6-year follow-up	https://doi.org/10.1016/j.anl.2015.09.010
Mehtap Balaban et al. (2016)	1	66/F	18	Liver, lung, brain	NR	NR	https://doi.org/10.12659/PJR.895430
Levent Renda et al. (2016)	1	74/F	0	Nil	Superficial parotidectomy	NR	Renda, Levent & İlden, Oğuzhan & Selcuk, Ömer & Süren, Dinç & Eyigör, Hülya. (2016). Parotid metastasis of renal cell carcinoma. ENTcase. 2.6–10
Faiz Hussain et al. (2016)	1	65/M	96	Nil	Surgical excision, RT	NR	https://doi.org/10.3402/jchimp.v6.31950
Hanna Majewska et al. (2016)	5	66/F, 76/F, 68/M, 69/M, -/M	11–228	-/NR	Parotidectomy ± RT	NR	https://doi.org/10.5114/pjp.2016.59475
B.J. Rocca et al. (2017)	1	60/M	0	Lung	Partial nephrectomy	NR	PMID: 29449729
Anja Lieder et al. (2017)	1	74/-	78	Nil	Parotidectomy	Alive at 56 m	https://doi.org/10.1590/S1677-5538.IBJU.2015.0665
Guy Sydney et al. (2019)	1	75/F	108	-/NR	Partial superficial parotidectomy	NR	https://doi.org/10.2478/bjdm-2019-0020
Rafael Netto et al. (2019)	1	68/M	0	Bone	Chemotherapy, RT	4 m	https://doi.org/10.1155/2019/6840873
Present case (2020)	1	63/M	0	Lung, adrenal, bone, nodes, maxillary sinus	Pazopanib, bisphosponates	Alive	-

Abbreviations: RCC renal cell carcinoma, NR not reported, RT radiotherapy

The treatment of localized RCC is surgery. The treatment armamentarium of metastatic RCC is fast evolving with immune checkpoint inhibitors and tyrosine kinase inhibitors coming into practice and the median survival has dramatically improved over the past years.

To conclude, metastatic parotid masses are not infrequent and hence should not be forgotten when dealing with such de novo masses. This case report is being compiled to highlight the importance of keeping RCC as one among the differential diagnosis of infradiaphragmatic primary tumours.

Author Contribution

All authors have read and approved the manuscript.

Declarations

Patient Consent

Informed consent was obtained from all participants.

Conflict of Interest

The authors declare no competing interests.