Endobronchial metastasis from renal cell carcinoma: CT findings in four patients

Endobronchial metastasis secondary to renal clear cell carcinoma: A case report

BACKGROUND

Endobronchial metastases (EBMs) are tumours that metastasise from a malignant tumour outside the lungs to the central and subsegmental bronchi, and are visible under a bronchofibrescope. Most EBMs are formed by direct invasion or metastasis of intrathoracic malignant tumours, such as lung cancer, oesophageal cancer or mediastinum tumours. Renal cell carcinoma (RCC), accounting for 2% to 3% of all tumours, is a common malignant tumour of the urinary system. Renal clear cell carcinoma (RCCC) constitutes the predominant pathological subtype of RCC, comprising approximately 70% to 80% of all RCC cases. RCCC can spread and metastasise through arterial, venous and lymphatic circulation to almost all organs of the body. Moreover, lung, bone, liver, brain and local recurrence are the most common metastatic neoplasms of RCCC. However, EBM from RCCC has a low complication rate and is often misdiagnosed as primary lung cancer.

CASE SUMMARY

A 71-year-old male patient who had undergone radical left nephrectomy 7 years prior due to RCCC was referred to our hospital due to a 1-mo history of productive cough. The results of an enhanced chest CT scan indicated the presence of a soft tissue nodule in the upper lobe of the left lung, and flexible bronchoscopy revealed a hypervascular lesion in the bronchus of the left lung's superior lobe. Therefore, the patient underwent thoracoscopic left superior lobe wedge resection, and pathology confirmed EBM from the RCCC.

CONCLUSION

EBM from RCCC has a low incidence and no characteristic clinical manifestations in the early stage. If a bronchial tumour is found in a patient with RCCC, the possibility of bronchial metastatic cancer should be considered.

Life-threatening hemoptysis in patients with metastatic kidney cancer

Hemoptysis is a complication of intrathoracic tumors, both primary and metastatic, and the risk may be increased by procedural interventions as well as Stereotactic Ablative Radiation (SAbR). The risk of hemoptysis with SAbR for lung cancer is well characterized, but there is a paucity of data about intrathoracic metastases. Here, we sought to evaluate the incidence of life-threatening/fatal hemoptysis (LTH) in patients with renal cell carcinoma (RCC) chest metastases with a focus on SAbR. We systematically evaluated patients with RCC at UT Southwestern Medical Center (UTSW) Kidney Cancer Program (KCP) from July 2005 to March 2020. We queried Kidney Cancer Explorer (KCE), a data portal with clinical, pathological, and experimental genomic data. Patients were included in the study based on mention of "hemoptysis" in clinical documentation, if they had a previous bronchoscopy, or had undergone SAbR to any site within the chest. Two hundred and thirty four patients met query criteria and their records were individually reviewed. We identified 10 patients who developed LTH. Of these, 4 had LTH as an immediate procedural complication whilst the remaining 6 had prior SAbR to ultra-central (UC; abutting the central bronchial tree) metastases. These 6 patients had a total of 10 lung lesions irradiated (UC, 8; central 1, peripheral 1), with a median total cumulative SAbR dose of 38 Gray (Gy/ lesion) (range: 25-50 Gy). Other risk factors included intrathoracic disease progression (n = 4, 67%), concurrent anticoagulant therapy (n = 1, 17%) and concurrent systemic therapy (n = 4, 67%). Median time to LTH from first SAbR was 26 months (range: 8-61 months). Considering that 130 patients received SAbR to a chest lesion during the study period, the overall incidence of LTH following SAbR was 4.6% (6/130). The patient population that received SAbR (n = 130) was at particularly high risk for complications, with 67 (52%) having two or more chest metastaes treated, and 29 (22%) receiving SAbR to three or more lesions. Overall, the risk of LTH following SAbR to a central or UC lesion was 10.5% (6/57). In conclusion, SAbR of RCC metastases located near the central bronchial tree may increase the risk of LTH.

Endobronchial metastasis secondary to occulting renal cell carcinoma: literature review and a rare case report

BACKGROUND

Endobronchial Metastasis from extrathoracic tumors is a rare neoplasm that accounts for approximately 1.1% of total endobronchial malignancies. The most common primary tumors associated with EBM are from the colorectal, breast, and kidney regions. Although it represents a late manifestation in the context of tumor progression, it can rarely antedate the diagnosis of the primary tumor.

CASE PRESENTATION

A 67-years-old male was referred from another city hospital to our thoracic surgery department due to a 4-months history of hemoptysis and productive cough. A chest X-ray and computed tomography scan showed a soft-tissue mass within the left main bronchus and atelectasis of the anterior segment of the left upper lobe. Furthermore, a flexible bronchoscopy revealed a hypervascular lesion occluding completely the left upper lobe bronchus. The patient underwent lobectomy and pathological examination suggested endobronchial metastasis from clear cell renal cell carcinoma. A second computed tomography scan of the abdomen and pelvis showed a well-defined mass arising from the lateral aspect of the right kidney; therefore, the patient underwent right radical nephrectomy three weeks later and pathology confirmed the diagnosis of clear renal cell carcinoma with endobronchial metastasis.

CONCLUSION

Despite its rarity, physicians should consider the possibility of endobronchial metastases in the setting of endobronchial lesions. Proper diagnostic approaches should also be considered to rule out the potential of asymptomatic extrathoracic neoplasms. In this manuscript, we aimed to report a rare case -the first from Syria to our knowledge- of an endobronchial metastasis that preceded the diagnosis of renal cell carcinoma. Importantly, we reviewed the existing literature and discussed the diagnostic and treatment approaches.

CT Findings of Central Airway Lesions Causing Airway Stenosis-Visualization and Quantification: A Pictorial Essay

The tracheobronchial tree is a system of airways that allows the passage of air to aerate the lungs and entire body. Several pathological conditions can affect this anatomical region. Multidetector CT (MDCT) helps identify and characterize various large airway diseases. Post-processing tools, such as virtual bronchoscopy and automatic lung analysis, can help enhance the performance of imaging studies. In this pictorial essay review, we provide imaging findings of various bronchial lesions manifested as wall thickening and endoluminal nodules on conventional MDCT and advanced image visualization and analysis.

Bronchial arterial embolization may reduce the risk of severe bleeding in central airway obstruction due to renal cell carcinomas during bronchoscopic procedures

BACKGROUND

Hemorrhage is a life-threatening complication during bronchoscopic intervention in patients with central airway obstruction (CAO) due to metastatic renal cell carcinoma (RCC). Whether pre-bronchoscopic bronchial arterial embolization (BAE) can reduce the risk of severe bleeding in CAO patients due to metastatic RCC remains unclear.

METHODS

A total of 31 CAO patients due to metastatic RCC were included retrospectively and divided into a BAE group (receiving pre-bronchoscopic BAE) and non-BAE group in this study. Based on computed tomography (CT) and bronchoscopic findings, tumor debulking was used to reconstruct the airway during interventional bronchoscopy. The primary outcome was the incidence of severe bleeding during bronchoscopic procedures. Bleeding-related complications, Karnofsky performance score (KPS) and dyspnea score were also analyzed over a 1-month observation period.

RESULTS

There were no significant differences between the two groups in baseline characteristics, including patients' features, tumor morphology under CT scannings, tumor site, and obstruction degree under bronchoscopic examination. Procedure-related bleeding occurred in all 31 patients. Pre-bronchoscopic BAE significantly reduced the incidence of moderate and major bleeding when compared with that in the non-BAE group. The incidence of poor visualization and hypoxia was also reduced significantly in the BAE group. There was no significant difference in KPS and dyspnea score between the BAE and non-BAE groups at 1 month follow up.

CONCLUSION

Pre-bronchoscopic BAE might be a feasible option to reduce the risk of severe bleeding for CAO patients due to metastatic RCC during bronchoscopic intervention. Interventional bronchoscopy was a safe and effective procedure for CAO due to metastatic RCC.The reviews of this paper are available via the supplemental material section.

Thoracic Manifestations of Genitourinary Neoplasms and Treatment-related Complications

Genitourinary (GU) malignancies are a diverse group of common and uncommon neoplasms that may be associated with significant mortality. Metastases from GU neoplasms are frequently encountered in the chest, and virtually all thoracic structures can be involved. Although the most common imaging manifestations include hematogenous dissemination manifesting with peripheral predominant bilateral pulmonary nodules and lymphatic metastases manifesting with mediastinal and hilar lymphadenopathy, some GU malignancies exhibit unique features. We review the general patterns, pathways, and thoracic imaging features of renal, adrenal, urothelial, prostatic, and testicular metastatic neoplasms, as well as provide a discussion of treatment-related complications that might manifest in the chest. Detailed reporting of these patterns will allow the imager to assist the referring clinicians and surgeons in accurate determination of the stage, prognosis, and treatment options available for the patient. Awareness of specific treatment-related complications further allows the imager to enhance patient safety through accurate and timely reporting of potentially life-threatening consequences of therapies.

Imaging and Management of Intrathoracic Renal Cell Carcinoma Metastases

OBJECTIVE

Renal cell carcinoma (RCC) has a propensity to metastasize to the chest, with the lungs being the most common distant metastatic site. The histologic subtype of RCC has implications for prognosis.

CONCLUSION

Significant advances have been made in the management of metastatic RCC, both in systemic and locoregional therapies. The aim of this article is to review appearances of intrathoracic metastases from RCC and to discuss treatment considerations.

Techniques of endoscopic airway tumor treatment

Interventional bronchoscopy has a predominant role in the management of both early and advanced-stage airway tumors. Given the very poor prognosis of lung cancer, there is a need for new tools to improve early detection and bronchoscopic treatment of endo-bronchial precancerous lesions. In more advanced stages, interventional bronchoscopy plays an important role, as nearly a third of lung cancers lead to proximal airway obstruction. This will cause great discomfort or even life-threatening symptoms related to local extension, such as dyspnea, post-obstructive pneumonia, and hemoptysis. Surgery for very locally advanced disease is only effective for a limited number of patients and the effects of conventional antitumor therapies, like radiation therapy or chemotherapy, are inconstant and are too delayed in a palliative context. In this review, we aim to provide pulmonologists with an exhaustive technical overview of (I) the bronchoscopic management of benign endobronchial lesions; (II) the bronchoscopic management of malignant tumors, including the curative treatment of localized lesions and palliative management of malignant proximal airway stenosis; and (III) descriptions of the emerging endoscopic techniques used to treat peripheral lung tumors.

Multidimensional evaluation of tracheobronchial disease in adults

The large airways can be affected by a wide spectrum of acquired benign and malignant diseases. These lesions may present as focal or diffuse processes and with narrowing or widening of the airway. Some of these may be asymptomatic for quite some time and may be incidentally detected on imaging, while others may be symptomatic, causing airway compromise. There may be a characteristic radiograph and computed tomography (CT) appearance, suggesting a narrow differential. When the imaging findings are not definitive, tissue may be obtained for pathological analysis. It behooves the radiologist to be familiar with the pathologic findings that correlate with the radiographic or CT appearance of the most frequently seen large airway lesions. In this way, we may improve our diagnostic accuracy. This paper will present the imaging findings of the most prevalent tracheobronchial lesions along with any associated pathology. Teaching Points • The large airways can be affected by many acquired benign and malignant diseases.• Large airway lesions may present as focal or diffuse processes, with narrowing or widening.• There may or may not be characteristic imaging appearance of large airway disease.• If imaging findings are not definitive, tissue may be obtained for pathological analysis.

Pulmonary manifestations of renal cell carcinoma

Renal cell carcinoma (RCC) accounts for majority of all primary renal neoplasms. Classic manifestations of RCC include the triad of flank pain, hematuria and a palpable renal mass. Patients with RCC can develop various extra renal manifestations including involvements of the lungs, inferior vena cava, liver and the bones. The pulmonary manifestations of renal cell carcinoma include metastatic disease including endobronchial, pleural, parenchymal or lymph node metastasis, pleural effusion or hemothorax. Pulmonary embolism and tumor embolism is another common manifestation of renal cell carcinoma. RCC is a highly vascular tumor and can cause pulmonary arterio-venous fistulas leading to high output failure. Rarely, RCC can also present with paraneoplastic presentations including cough or bilateral diaphragm paralysis. Drugs used to treat RCC have been associated with drug related pneumonitis and form an important differential diagnosis in patients with RCC on therapy presenting with shortness of breath. In this review we discuss the various pulmonary manifestations of RCC. A high index of suspicion with these presentations can lead to an early diagnosis and assist in instituting an appropriate intervention.

Endobronchial metastasis from resected renal cell carcinoma causing total lung collapse

We report a man presenting with dyspnea, cough, and hemoptysis due to left lung collapse from an endobronchial tumor obstructing the left main bronchus. Endobronchial biopsy of the tumor showed renal cell carcinoma, identical to a previous specimen of renal cell carcinoma removed by a radical left nephrectomy five years ago. The endobronchial tumor was removed by snare diathermy through a flexible bronchoscope, following which his symptoms resolved and the left lung re-expanded. Endobronchial metastasis from renal cell carcinoma is rare and can mimic obstruction from other endobronchial etiologies, such as bronchogenic carcinoma. Total lung collapse as a result is even more uncommon, although atelectasis is well described. Endobronchial techniques, such as snare diathermy, can relieve obstruction, providing symptom palliation even in advanced disease.

Tumors in the tracheobronchial tree: CT and FDG PET features

A variety of tumors, including primary malignant tumors, secondary malignant tumors, and benign tumors, can occur in the tracheobronchial tree. Primary malignant tumors commonly originate from the surface epithelium or the salivary glands, whereas most benign tumors arise from the mesenchymal tissue. At computed tomography (CT), primary malignant tumors manifest as a polypoid lesion, a focal sessile lesion, eccentric narrowing of the airway lumen, or circumferential wall thickening. At fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography (PET), most squamous cell carcinomas show high uptake, whereas adenoid cystic carcinoma and mucoepidermoid carcinoma show variable uptake depending on the grade of differentiation. High-grade malignancies tend to show high and homogeneous uptake. Carcinoid tumors commonly show intense enhancement at contrast material-enhanced CT, which can be helpful in making the diagnosis, and usually have lower uptake at FDG PET than would be expected for a malignant tumor. Secondary malignant tumors occur as a result of either hematogenous metastasis or direct invasion by a malignancy from an adjacent structure. Their CT manifestations are similar to those of primary malignant tumors, with uptake at FDG PET depending primarily on the metabolic activity and degree of differentiation of the primary tumor. Among the benign tumors, hamartoma and lipoma can show characteristic CT findings such as "popcorn" calcification or internal fat. However, CT findings in most benign tumors are nonspecific. At FDG PET, benign tumors usually show little or no uptake and can be differentiated from malignant tumors. Knowledge of the characteristic CT and FDG PET findings of tracheobronchial tumors can aid in diagnosis and treatment planning.

Mucoid impactions: finger-in-glove sign and other CT and radiographic features

Mucoid impaction is a relatively common finding at chest radiography and computed tomography (CT). Both congenital and acquired abnormalities may cause mucoid impaction of the large airways that often manifests as tubular opacities known as the finger-in-glove sign. The congenital conditions in which this sign most often appears are segmental bronchial atresia and cystic fibrosis. The sign also may be observed in many acquired conditions, include inflammatory and infectious diseases (allergic bronchopulmonary aspergillosis, broncholithiasis, and foreign body aspiration), benign neoplastic processes (bronchial hamartoma, lipoma, and papillomatosis), and malignancies (bronchogenic carcinoma, carcinoid tumor, and metastases). To point to the correct diagnosis, the radiologist must be familiar with the key radiographic and CT features that enable differentiation among the various likely causes. CT is more useful than chest radiography for differentiating between mucoid impaction and other disease processes, such as arteriovenous malformation, and for directing further diagnostic evaluation. In addition, knowledge of the patient's medical history, clinical symptoms and signs, and predisposing factors is important.

Mucoid impaction secondary to mucin-producing metastatic adenocarcinoma of the cervix

Endobronchial metastases are an uncommon complication of malignant tumours. The vast majority are secondary to carcinoma of the breast, colorectum and kidney, or to melanoma. Occasionally, endobronchial tumours can result in partial or complete bronchial obstruction. Here, we describe an uncommon case of endobronchial metastasis of adenocarcinoma of the cervix causing mucoid impaction owing to mucous production by the tumour cells.