Diseases of the Mediastinum and Pleura JIM LAVELLE

Diseases of the Mediastinum and Pleura JIM LAVELLE, MD ASSOCIATE PROFESSOR OF MEDICINE APRIL 29, 2019

THE MEDIASTINUM

Diaphragm inferiorly Sternum anteriorly Parietal pleura bilaterally Thoracic inlet superiorly Paravertebral gutters and ribs posteriorly Anatomy of the Mediastinum

Compartments of the Mediastinum ANTERIOR MIDDLE POSTERIOR

Anterior. Superior Compartment Thymus Gland Aortic root and great vessels Substernal thyroid and parathyroid tissue Lymphatic vessels and nodes Inferior aspect of trachea

Middle Compartment Pericardial Sac Heart Innominate veins and SVC Trachea and major bronchi Hila Lymph nodes Phrenic, upper vagus and recurrent laryngeal nerves

Posterior Compartment Esophagus Descending aorta Azygous and hemiazygous veins Thoracic duct Lymph nodes Vagus nerves (lower portion) Sympathetic chains

Mediastinal Masses Can be asymptomatic or symptomatic ◦ Incidental finding on imaging ◦ Local symptoms ◦ Compression of adjacent structures ◦ Invasion of adjacent structures ◦ Systemic symptoms ◦ Fever, anorexia, weight loss ◦ Endocrine syndromes ◦ Autoimmune symptoms (thymus related) Can be benign or malignant ◦ 80% of asymptomatic masses are benign ◦ 50% of symptomatic masses are malignant

Mediastinal Masses Differential diagnosis by location Differential diagnosis by age ◦ Adults: ◦ 65% anterior ◦ 25% posterior ◦ 10% middle ◦ Children: ◦ 65% posterior ◦ 25% anterior Only one-third of lesions in adults are symptomatic Two-thirds of lesions in children are symptomatic

Diagnostic Evaluation: Clinical History Symptoms associated with obstruction of contiguous organs ◦ Dysphagia, hoarseness ◦ SVC syndrome (facial/upper extremity swelling) ◦ Cough, stridor, hemoptysis, shortness of breath ◦ Horner syndrome (sympathetic chain) B Symptoms ◦ Fevers ◦ Weight Loss ◦ Drenching night sweats

Diagnostic Evaluation: Physical Exam Blood pressure Weight loss Lymphadenopathy Exam of the head, neck, upper extremities, and chest

Diagnostic Evaluation: Imaging Routine CXR (PA and Lateral) ◦ Localize the mediastinal compartment CT chest ◦ Anatomic localization ◦ Differentiate between cyst vs. solid lesions ◦ Identify fatty structures ◦ Lymphadenopathy vs. vascular structures

Which compartment?

Anterior Compartment Masses Differential Diagnosis: Thymic neoplasm Teratoma ◦ Germ cell tumor (Terrible) Lymphoma ◦ Hodgkin’s disease ◦ Non-hodgkin’s lymphoma 4 Terrible T’s Thyroid neoplasm Mesenchymal neoplasm Diaphragmatic hernia (Morgagni) Primary carcinoma

Which compartment?

Differential Diagnosis: Middle Compartment Masses Lymphadenopathy Developmental cysts ◦ Pericardial cyst ◦ Bronchogenic cyst ◦ Enteric cyst Reactive and granulomatous inflammation Metastasis Lymphoma Vascular enlargements Diaphragmatic hernia (hiatal)

Differential Diagnosis: Middle Compartment Masses Lymphadenopathy Developmental cysts ◦ Pericardial cyst ◦ Bronchogenic cyst ◦ Enteric cyst Reactive and granulomatous inflammation Metastasis Lymphoma Vascular enlargements Diaphragmatic hernia (hiatal)

Which compartment?

Differential Diagnosis: Posterior Compartment Masses Peripheral nerve (neurinomas) Neurogenic tumors Sympathetic ganglia Paraganglionic tissue Meningocoele Esophageal lesions Carcinoma Diverticuli Diaphragmatic hernia (Bochdalek)

Differential Diagnosis: Posterior Compartment Masses Peripheral nerve (neurinomas) Neurogenic tumors Sympathetic ganglia Paraganglionic tissue Meningocoele Esophageal lesions Carcinoma Diverticuli Diaphragmatic hernia (Bochdalek)

Diagnostic Evaluation: Laboratory and tissue studies Needle Aspiration ◦ Transbronchial Needle Aspiration -HCG, -fetoprotein ◦ Percutaneous Needle Aspiration / Bx Anti-acetylcholine receptor ◦ Endoscopic ultrasound guided Asp / Bx CBC with differential antibodies Surgical ◦ Mediastinoscopy ◦ Thoracoscopy

Complications of Mediastinal Masses Tracheal Obstruction SVC syndrome Vascular invasion ( hemorrhage) Esophageal rupture

THE PLEURA

The Pleura Two, single-cell thick, continuous membranes that line the outer surface of the lung (VISCERAL) and inner surface of the thoracic cavity (PARIETAL) Meet at the hilar root of the lung The pleural space is the potential space between the two membranes

Disorders of the Pleura Pneumothorax Pleural effusions Pleural based abnormalities

PNEUMOTHORAX

Size of the pneumothorax

Types of Pneumothoraces Spontaneous Traumatic Primary Iatrogenic Secondary - Complication of trans-thoracic needle biopsy - COPD - Complication of central line placement - PCP, Mtb, Necrotizing pneumonia Barotrauma - Cystic fibrosis - intubation - ILDs (e. g. lymphangioleiomyomatosis) - mechanical ventilation - Pneumoconoiosis Trauma - Lung Cancer - penetrating - non-penetrating

Primary Spontaneous Pneumothorax No precipitating event (occurs at rest) No known lung disease Men, smokers, family history of PSP Recurrence in 25 -54% Peak age in early 20 s

Diagnostic Evaluation: Clinical History Acute onset chest pain Dyspnea Cough Anxiety Cyanosis Respiratory distress

Diagnostic Evaluation: Physical Exam Hyper resonant chest percussion Decreased / absent breath sounds Decreased fremitus Chest wall trauma Decreased rib space

Diagnostic Evaluation: Imaging - CXR - CT chest - Ultrasound can show absence of pleural slide

Conditions that can mimic a PTX Bullae Skin folds Stomach herniation following traumatic rupture of the left hemidiaphragm N Engl J Med 2011; 365: 1915

Treatment Observation Supplemental oxygen (100%) Simple aspiration Tube thoracostomy (chest tube) Pleurodesis

Tension Pneumothorax Intrapleural pressure exceeds atmospheric pressure throughout expiration and often during inspiration Causes hemodynamic compromise by decreasing venous return and limiting cardiac output Medical emergency Signs and symptoms - tachycardia, hypotension, cyanosis, respiratory distress

Treatment Do NOT wait for confirmatory chest radiograph Emergently insert an 18 gauge angiocath in the second intercostal space along the midclavicular line Place tube thoracostomy if pneumothorax confirmed

Insert an 18 G angiocath in the second intercostal space along the MCL Attach a piece of IV tubing to the end and place the other end in a cup of saline

PLEURAL EFFUSION Normal production 0. 2 -0. 3 m. L/kg Occurs when the rate of pleural fluid formation exceeds drainage Associated with both localized pleural disorders and systemic conditions that affect the pleura.

Diagnostic Evaluation: Clinical History & Exam Dyspnea Pleuritic chest pain Dry cough Symptoms associated with underlying cause Decreased breath sounds, dullness to percussion, decreased tactile and vocal fremitus on examination

Diagnostic Evaluation: Imaging CXR CT scan Ultrasound

Classification of Pleural Effusions Transudative effusions result from alteration in hydrostatic forces that affect fluid formation (nonprotein rich). Exudative effusions are due to alterations in permeability of the pleura or rate of fluid removal (protein rich).

Diagnostic Evaluation: Thoracentesis

Pleural Fluid Analysis LDH (+serum) Total protein (+serum) p. H Glucose Cell counts (wbc, rbc) and differential Gram stain, routine culture AFB / fungal stains and culture Cytology

Light’s Criteria TRANSUDATE EXUDATE LDHpl/LDHser < 0. 6 And Protpl/Protser < 0. 5 LDHpl/LDHser > 0. 6 Or Protpl/Protser > 0. 5 Or LDHpl 2/3 upper limit normal for serum

Differential Diagnosis for Transudate Congestive Heart Failure Cirrhosis with ascites Nephrotic syndrome Peritoneal dialysis Myxedema Acute atelectasis Congestive pericarditis Superior Vena Cava syndrome Fontan procedure Urinothorax

Differential Diagnosis for Exudate Infection Cancer Pulmonary embolism Post-CABG Post-MI syndrome Connective tissue disease GI disease Asbestos Sarcoidosis Uremia Drug reaction Chronic atelectasis/trapped lung Radiation therapy Hemothorax Chylothorax

PLEURAL BASED ABNORMALITIES Pleural Thickening Pleural Plaques Pleural Tumors

Pleural Thickening CT definition Etiology ◦ Inflammation following infection ◦ Hemorrhage ◦ Prior treatment for effusion/ptx ◦ Occupational exposure (i. e. asbestos) ◦ Trauma ◦ Neoplasm

Pleural Plaques Chronic inflammation Asbestos exposure ◦ 20 -30 years after initial exposure

Pleural Tumors Majority are malignant Majority are metastatic ◦ Lung 37. 5% ◦ Breast 16. 8% ◦ Lymphoma 11. 5% ◦ Gastrointestinal 6. 9% ◦ Genitourinary 9. 4%

Questions?