What is the Difference Between Lung Mass and Mediastinal Mass

The key difference between lung mass and mediastinal mass is that lung mass is an abnormal spot or area solely arising within lungs, while mediastinal mass is an abnormal spot or area solely arising from structures within the mediastinum.

An abnormal mass of tissue is formed when cells divide more than the normal rate. In a normal body, cells divide, grow and replace other cells throughout the life cycle. New cells grow while the old cells die. If there are too many new cells above the expected level, a tumor can develop. Some cell masses are benign, but some are malignant. Lung mass and mediastinal mass are two types of cell masses formed due to abnormal cell growth.

CONTENTS

1. Overview and Key Difference
2. What is Lung Mass
3. What is Mediastinal Mass
4. Similarities – Lung Mass and Mediastinal Mass
5. Lung Mass vs Mediastinal Mass in Tabular Form
6. Summary – Lung Mass vs Mediastinal Mass

What is Lung Mass?

A lung mass is defined as an abnormal spot in the lung that is larger than 3 cm or 1.5 inches. The spots smaller than this size are known as lung nodules. The common causes of lung mass are different from lung nodules. Therefore, it is very important to differentiate a lung mass from a lung nodule. The chance that this abnormal cell growth may be malignant (cancerous) is higher for a lung mass than it is for a lung nodule. About 4-5 % of lung masses turn out to be lung cancers.

Lung cancer is currently a leading cause of death in men and women in the US. Cancers other than lung cancer, such as lymphoma and sarcoma, can also appear as a mass in the lungs. Sometimes metastatic cancers like breast cancer and colon cancer may also appear as a mass in the lungs. Moreover, some benign causes of lung mass are lung abscesses, AV malformation, lipoid pneumonia, fungal infection, parasitic infection, and amyloidosis. Diagnosis can be made through physical examination, imaging (X-ray, CT scan, MRI), fine needle biopsy, and bronchoscopy. The treatments may include surgery, chemotherapy and radiation therapy for lung cancers and other medications for other benign causes of lung mass. Lung cancer treatment methods have advanced over the years. Immunotherapy drugs give durable responses for even people in the advanced stages of cancer.

What is Mediastinal Mass?

Mediastinal mass is an abnormal spot or area solely arising from structures within the mediastinum. It is caused due to various neoplastic and non-neoplastic pathologies. The mediastinum is surrounded by the middle part of the chest. It is normally divided into three parts: anterior, middle, and posterior. Anterior mediastinal masses are thymoma, lymphoma, germ cell tumor, and thyroid mass (substernal goiter). Middle mediastinal masses include bronchogenic cyst and pericardial cyst. Moreover, posterior mediastinal masses include neurogenic tumor.

Diagnosis of these masses can be made through blood tests, CT guided needle biopsy, mediastinoscopy, anterior mediastinotomy, endobronchial ultrasound, etc. The treatment methods of mediastinal cancers include minimally invasive surgery, chemotherapy and radiation therapy. Some masses, if they are not cancerous, are just monitored over time.

What are the Similarities Between Lung Mass and Mediastinal Mass?

• Lung mass and mediastinal mass are two types of cell masses due to abnormal cell growth.
• They form due to an imbalance between cell growth and cell death.
• Both masses can be benign or malignant.
• They are treatable.

What is the Difference Between Lung Mass and Mediastinal Mass?

Lung mass is an abnormal spot or area solely arising within the lungs, while mediastinal mass is an abnormal spot or area solely arising from structures within the mediastinum. So, this is the key difference between lung mass and mediastinal mass. Furthermore, lung mass mostly affects the 60 to 75 years age group, while mediastinal mass mostly affects the 30 to 50 years age group.

The following infographic lists the differences between lung mass and mediastinal mass in tabular form for side by side comparison.

Summary – Lung Mass vs Mediastinal Mass

Cell masses are abnormal masses of tissue formed when cells divide rapidly. They can be benign or cancerous.  Lung mass and mediastinal mass are two types of cell masses due to abnormal cell growth. Lung mass is an abnormal spot or area located within the lungs, while mediastinal mass is an abnormal spot or area located within the mediastinum. Thus, this summarizes the difference between lung mass and mediastinal mass.

Reference:

1. Lynne Eldridge, MD. “Does a Lung Mass Mean You Have Cancer?” Verywell Health.
2. “Mediastinal TUMORS: Causes, SYMPTOMS, Diagnosis & Treatments.” Cleveland Clinic.

Image Courtesy:

1. “Chest x-ray showing a lung mass” By NIH Image Gallery (CC BY-NC 2.0) via Flickr
2. “Anterior mediastinal mass thymoma diagram” By Mohankumar Kurukumbi, Roger L Weir, Janaki Kalyanam, Mansoor Nasim, Annapurni Jayam-Trouth. – Rare association of thymoma, myasthenia gravis and sarcoidosis : a case report. Journal of Medical Case Reports. 2008;2:245. doi:10.1186/1752-1947-2-245 (CC BY 2.0) via Commons Wikimedia