How should a potentially malignant hilar mass be diagnosed and treated if it could be either a carcinoma or an adenoma?

From the Guidelines

A potentially malignant hilar mass should be diagnosed and treated based on a comprehensive approach that prioritizes tissue diagnosis to distinguish between carcinoma and adenoma, given the significant implications for prognosis and treatment. The initial evaluation of a hilar mass should include non-invasive imaging such as a contrast-enhanced CT scan of the chest and abdomen, followed by PET-CT to assess metabolic activity and potential metastases 1. Tissue diagnosis is crucial and can be obtained via bronchoscopy with endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA), which allows for the sampling of hilar lymph nodes with minimal invasiveness. If EBUS is non-diagnostic, mediastinoscopy or video-assisted thoracoscopic surgery (VATS) may be necessary to obtain adequate tissue. The distinction between primary lung cancers and metastatic lung cancers is made through clinical history, patient presentation, radiographic and imaging techniques, and optimal specimen acquisition and evaluation 1. Immunohistochemical analysis, including markers such as TTF-1, CK7, and CK20, can greatly assist in the differential diagnosis of primary vs metastatic carcinoma and in identifying the primary origin of metastatic tumors of unknown origin 1. Treatment depends on the final diagnosis: for carcinoma, options include surgical resection for early-stage disease, or for advanced disease, a combination of chemotherapy, radiation therapy, and possibly immunotherapy based on PD-L1 status and molecular testing. For benign adenomas, complete surgical excision is typically curative. Given the more recent guidelines on managing cancers, such as the update on liver cancer management 1, it's essential to consider the latest approaches in oncology for hilar masses, even though the specific guidelines provided may not directly address lung hilar masses, the principle of comprehensive diagnosis and tailored treatment applies. Therefore, the most critical step in managing a potentially malignant hilar mass is achieving an accurate diagnosis through a combination of imaging and tissue sampling, followed by treatment tailored to the specific pathology, whether carcinoma or adenoma.

From the Research

Diagnosis of Hilar Mass

• The diagnosis of a potentially malignant hilar mass can be approached through various imaging modalities, including ultrasound, computerized tomography (CT), magnetic resonance imaging (MRI), and scintigraphic procedures 2.
• Ultrasound is useful for guiding fine needle aspiration to improve the accuracy of cytological analysis, while CT or MRI can better define tumor extension to neighboring structures 2.
• For a definitive diagnosis, biopsy is often necessary, and anatomical imaging procedures can be highly sensitive but not specific for postoperative evaluation 2.

Treatment Options

• The choice of treatment for a hilar mass depends on the type, location, and size of the tumor, as well as the patient's overall health and medical history 3.
• Minimally invasive, image-guided techniques for local tumor treatment are available, including percutaneous injection of a toxic substance, transarterial embolization, thermal ablation, and internal radiotherapy 3.
• The outcome of treatment depends on a judicious determination of the indication for it, and the indication should be established by interdisciplinary consensus after all treatment options have been considered 3.

Prognostic Factors

• The prognosis of a patient with a hilar mass depends on various factors, including the stage and grade of the tumor, as well as the patient's age, sex, and overall health 4, 5.
• Treatment with radioactive iodine can be an effective prognostic indicator for increased disease-free interval and survival in patients with well-differentiated thyroid carcinoma 5.
• Advanced age, prior history of malignancy, weight loss, abnormally high percentage of monocytes, and thrombocytosis may be predictive of a cancer diagnosis in patients with suspected malignancy 6.

Diagnostic Evaluation

• The diagnosis of cancer is based on the demonstration of malignant cells obtained via biopsy or needle aspiration, and diagnostic options may be limited by tumor location, underlying comorbid conditions, or lack of access to care 6.
• Endoscopic ultrasonography with fine needle aspiration (EUS/FNA) and image-guided percutaneous biopsy (IGPB) are commonly used diagnostic techniques, with a low risk of complications 6.
• Comorbid medical conditions are common among patients and occur at rates similar to the general population, and further study is necessary to determine organ-specific predictors of malignancy and to better understand the relationship between cancer and coexisting medical conditions 6.