MEDIASTINAL MASSES

OKIEMUTE RITA OBODO

1005

TABLE OF CONTENTS

• INTRODUCTION

• CAUSES

• SIGNS AND SYMPTOMS

• COMPLICATIONS

• DIAGNOSIS

• MANAGEMENT/TREATMENT

• CASE STUDY

• REFERENCES

WHAT ARE MEDIASTINAL MASSES?

• Mediastinal masses are benign or cancerous growths that form in the area of the chest that separates the lungs. This area, called the mediastinum, is surrounded by the breastbone in front, the spine in back, and the lungs on each side. The mediastinum contains the heart, aorta, esophagus, thymus and trachea.

THE MEDIASTINUM IS DIVIDED INTO:

ANTERIOR MEDIASTINUM:

• Germ cell - The majority of germ cell neoplasms (60 to 70%) are benign and are found in both males and females.

• Lymphoma – Malignant tumors that include both Hodgkin’s disease and non Hodgkin’s lymphoma.

• Thymoma and thymic cyst - The most common cause of a thymic mass, the majority of thymomas are benign lesions that are contained within a fibrous capsule. However, about 30% of these may be more aggressive and become invasive through the fibrous capsule.

• Thyroid mass mediastinal – Usually a benign growth, such as a goiter, these can occasionally be cancerous.

CASE 1:The patient is a 65 year old

man with a history of hypertension and valvular

heart disease who presented with spontaneous hemorrhage

of the right lower extremity soft tissue. He had neither

constitutional nor ocular symptoms and no evidence of muscular weakness. A chest x-

ray showed an anterior mediastinal mass confirmed by

CT scan. The mass was contiguous with the inferior thymus. CT-guided biopsy of the mass was performed and

cytologic analysis of the aspirate showed keratin- and

vimentin-positive spindle cells. The anterior mediastinal mass

was surgically resected

MIDDLE MEDIASTINUM:

• Bronchogenic cyst – A benign growth with respiratory origins.

• Lymphadenopathy mediastinal – An enlargement of the lymph nodes.

• Pericardial cyst – A benign growth that results from an "out-pouching" of the pericardium (the heart’s lining).

• Thyroid mass mediastinal – Usually a benign growth, such as a goiter. These types of tumors can occasionally be cancerous.

• Tracheal tumors – These include tracheal neoplasms and non-euplastic masses, such as tracheobronchopathia osteochondroplastica (benign tumors).Vascular abnormalities including aortic aneurysm and aortic dissection.

POSTERIOR MEDIASTINUM:• Extramedullary haematopoiesis – A rare cause of masses

that form from bone marrow expansion and are associated with severe anemia.

• Lymphadenopathy mediastinal – An enlargement of the lymph nodes.

• Neuroenteric cyst mediastinal – A rare growth, which involves both neural and gastrointestinal elements.

• Neurogenic neoplasm mediastinal – The most common cause of posterior mediastinal tumors, these are classified as nerve sheath neoplasms, ganglion cell neoplasms, and paraganglionic cell neoplasms. Approximately 70% of neurogenic neoplasms are benign. Oesophageal abnormalities including achalasia oesophageal, oesophageal neoplasm and hiatal hernia. Vascular abnormalities – Includes aortic aneurysms.

CAUSES

• The cause of mediastinal tumors is often unknown. Although the cause may be unknown, certain kinds of mediastinal tumors may be associated with other conditions. For example, thymoma can be associated with other conditions, such as myasthenia gravis, polymyositis, lupus erythematosus, rheumatoid arthritis, and thyroiditis.

SIGNS AND SYMPTOMS

• About 40 percent of people with mediastinal tumors experience no symptoms at all. Most mediastinal tumors are discovered during a test for another reason. When symptoms occur, however, they often result from compression of the surrounding structures and may include: COUGH, SHORTNESS OF BREATH, CHEST PAIN, FEVER,CHILLS,NIGHT SWEATS, COUGHING UP BLOOD, HOARSENESS, UNEXPLAINED WEIGHT LOSS, LYMPHADENOPATHY (SWOLLEN OR TENDER LYMPH NODES), WHEEZING STRIDOR (HIGH-PITCHED, NOISY BREATHING THAT CAN SIGNAL AN OBSTRUCTION IN YOUR RESPIRATORY TRACT, ESPECIALLY THE TRACHEA OR LARYNX [VOICE BOX])

COMPLICATIONS

• Complications of mediastinal tumors include:

• Spinal cord compression

• Spread to nearby structures such as the heart, lining around the heart (pericardium), and great vessels (aorta and vena cava)

• Radiation, surgery, and chemotherapy can all have serious complications.

DIAGNOSIS

• A medical history and physical examination may show:

• Fever

• High-pitched breathing sound (stridor)

• Swollen or tender lymph nodes (lymphadenopathy)

• Unintentional weight loss

• Wheezing

DIAGNOSIS

• Chest x-ray

• Computed tomography (CT) scan of the chest or CT-guided needle biopsy

• Magnetic resonance imaging (MRI) of the chest

• Mediastinoscopy with biopsy (Performed under general anesthesia, this examination of the chest cavity uses a lighted tube inserted through a small incision under the chest bone; a sample of tissue is taken to determine if cancer is present. Mediastinoscopy with biopsy allows doctors to accurately diagnose 80 to 90% of mediastinal tumors, and 95 to 100% of anterior mediastinal tumors.)

TREATMENT

• The treatment used for mediastinal tumors depends on the type of tumor and its location:

• Thymic cancers require surgery, followed by radiation or chemotherapy. Types of surgery include thoracoscopy (a minimally invasive approach), mediastinoscopy (minimally invasive) and thoracotomy (a procedure performed through an incision in the chest).

• Lymphomas are recommended to be treated with chemotherapy followed by radiation.

• Neurogenic tumors found in the posterior (back) mediastinum are treated surgically.

CASE REPORT

• A 20 year old Caucasian man with no significant past medical history presented to his primary care physician for chest discomfort and cough. Two months prior to presentation, he reported having an unremarkable viral syndrome which resolved with no medical intervention. His primary care physician prescribed a short course of antibiotics for empiric treatment of pneumonia with some initial improvement in symptoms. His chest discomfort returned and he developed progressive dyspnea on exertion which led to a chest radiograph

CASE REPORT CONTD.

• An abnormality was noted in the left mediastinum which prompted his physician to order a computed tomography (CT) of the chest and to refer him to a pulmonary specialist. This CT scan revealed a rounded, well-demarcated mass in the superoanterior mediastinal compartment. The largest diameter measured 6.8 x 4.8cm

CASE REPORT CONTD.

• Further review of systems revealed subjective fever/chills along with night sweats. He denied wheezing, hemoptysis, weight loss, scrotal mass, palpable lymph nodes or any neurologic deficits.He was a non-smoker and did not take any medications or use illicit drugs

PHYSICAL EXAM

• The patient was in no acute distress. Vital signs were unremarkable. Cardiac exam demonstrated regular rate and rhythm with no murmur, gallop or rub. Lungs were clear to auscultation bilaterally without wheezes or rales. Abdomen was soft with no hepato/splenomegaly. There was no palpable cervical, supraclavicular or axillary lymphadenopathy. Genitourinary exam was negative for testicular masses. Neurologic exam showed no focal deficits. Cranial nerves appeared intact.

• http://path.upmc.edu/cases/case131/images/micro3.jpg

• http://www.thoracic.org/clinical/ats-clinical-cases/pages/12-12.php

• http://clinicaldepartments.musc.edu/anesthesia/intranet/education/resident%20research/files/Catherine%20Tobin.pdf

• http://www.nlm.nih.gov/medlineplus/ency/article/001086.htm

• http://lungcancer.about.com/od/glossary/g/mediastinum.htm

• http://www.meddean.luc.edu/lumen/MedEd/radio/curriculum/Pulmonary/mediastinum_teach.htm