OVERVIEW OF PRIMARY MEDIASTINAL TUMORS AND CYST GENERAL THORACIC SURGERY CHAPTER 160.
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Transcript of OVERVIEW OF PRIMARY MEDIASTINAL TUMORS AND CYST GENERAL THORACIC SURGERY CHAPTER 160.
OVERVIEW OF PRIMARY MEDIASTINAL TUMORS AND CYST
GENERAL THORACIC SURGERY
CHAPTER 160
Mediastinal tumor
• Numerous tumor and cyst occurred in mediastinum.
• Affect all age. • More common in young and middle-age adult. • Most mass are discovered on routine radiographic
examination. • Benign lesion most asymptomatic, malignant
lesion most produce clinical finding.
Mediastinal component
• Anterior compartment.
• Visceral compartment.
• Paravertebral sulci.
Location of common tumor and cyst
• Anterior mediastinum – Thymoma, lymphoma, germ cell tumor.
• Visceral compartment – Fore-gut cyst, bronchogenic cyst, esophageal, and gastric origin, secondary tumor of lymph node, pleuropericardial cyst, cystic lymphangioma.
• Paravertebral sulci – Neurogenic tumor, vascular tumor, mesenchymal tumor, lymphatic lesion, fibroma, lipoma.
Signs and symptoms
• child—2/3 with symptoms
• Adult 1/3 with symptoms.
• Symptom /sign dependent on benign and malignant, size, location, infection, endocrine or biochemical products.
Signs and symptoms
• Infant and child — Cough, dyspnea stridor are prominent even a small mass, septic complication with resultant pneumonitis, fever frequently.
• Adult — cough dyspnea, chest pain, s/s related infection, obstruction vital structure, invasion adjacent structure, pleural effusion, Horner’s syndrome, diaphragm paralysis.
Benignity versus malignancy
• Adult — Less 40% of anterior mediastinal tumor are malignant, almost all cyst are benign.
• Child — Incident of malignancy is high than adult, most malignant tumor are in child less than 3 y/o ( 86% ) , 91% benign lesion in older children, 45% lesion in child anterior compartment are malignant lymphoma.
Benignity versus malignancy
• Only small percentage of germ cell tumor in child are malignant.
• In visceral compartment —Mmany lymph node lesion are malignant.
DIAGNOSTIC INVESTIGATION OF MEDIASTINAL MASSES
GENERAL THORACIC SURGERY
CHAPTER 161
Noninvasive diagnostic procedures
• CT
• MRI
• Ultrasonography
• Radionuclide scanning
• Biochemical markers
CT• Routine. • More detail, invasion into adjacent structure pleural
or lung parenchymal metastases. • Sensitive method of distinguishing between fatty,
vascular, cystic, soft tissue mass. • Differentiation in solid and cystic mass– 100%. • Solid mass-- homogeneity or inhomogeneity. • Contrast enhancement of vessel.• Cannot differentiate between benign and malignant
tumor.
MRI
• Additional useful information in separation mediastinal tumor from vessels and bronchi.
• Superior to CT in evaluation intraspinal extention or intrathecal spread of paravertebral mass.
Ultrasonography
• -- Differentiation in solid and cystic.
Radionuclide scanning
• Thyroid – I131, I123. • Parathyroid – Tc 99m. • Octreotide – Somatostatin analogue, identifiy
small cell carcinoid tumors of lung. • Tc-99m–pertechnate scan – identified gastric
mucosa in suspected neuroenteric cyst in posterior portion of visceral compartment.
• Gallium 67 – differentiate benign from malignant anterior mediastinal mass.
Biochemical markers
• α-fetoprotein, β-human chorionic gonadotropin(β –HCG), ether one or both elevated in nonseminomatous malignant germ cell tumor.
• Excess than 500 ng/ml, can start chemotherapy without a tissue biopsy.
• 7-10% pure seminoma may elevated β- HCG but nor exceed 100 ng/ml, but elevated α-fetoprotein is never present.
Biochemical markers
• All infant and children with paravertebral mass should evaluated for excessive norepinephrine and epinephrine production.
• Ferritin level – for neuroblastoma.• Antiacetylcholine receptor antibodies–
thymoma.• Positron emission tomographic scanning –
Differentiating a noninvasive thymoma.
Invasive biopsy procedure
• Choice of invasive diagnostic procedures depends on
Presence or absence of local symptoms.
Location and extent of lesion.
Presence or absence various tumor marker.
Invasive biopsy procedure
• Do not require tissue biopsy before removal
Asymptomatic lesion without systemic
syndrome.
Confined in anterior compartment.
No elevating tumor marker.
• Biopsy of clinical stage I thymoma is to be avoid.
Percutaneous transthoracic fine-needle aspiration
• —CT or sono-guide. • Anterior compartment lesion—positive result
nearly 100%. • Complication is life-threating hemorrhage form
injury internal mammary artery during parasternal needle biopsy.
• CT-guide is much better. • Coaxial length-matched bone biopsy system guide
by CT.
Percutaneous transthoracic fine-needle aspiration
• Visceral compartment—transthoracically with passage of needle through lung.
• Success rate 75%.
• Complication pneumothorax is low.
• Paravertebral mass—CT-guide biopsy 100% success rate.
Mediastinoscopy
• Anterior mediastinal tumor, the mediastinoscopy is NOT appropriate for biopsy – May be obtain by cervical substernal extended mediastinotomy or anterior mediastinotomy.
• Lymph node confined to visceral compartment, biopsy via a standard cervical mediastinoscopy is used.