Posterior Mediastinal Masses - SUNY Downstate Medical … Mediastinal Masses_mlf.pdfImaging • CT chest • 4.4 x 4.3 x 6.6cm posterior mediastinal mass, partially ... Posterior Mediastinal

Posterior Mediastinal Masses

Marc LaFonte PGY 5

SUNY Downstate

www.downstatesurgery.org

Case Presentation • 78F admitted with progressive exertional dyspnea 3

months, new onset orthopnea • No dysphagia, weight change, pain, cough

• PSH: thyroidectomy (2001), left nephrectomy,

cholecystectomy • PMH: hypothyroidism, HTN, morbid obesity,

osteoporosis


Presenter

Presentation Notes

Presented January 2016 with exertional dyspnea over the last month 4 blocks to less than 1 block. Remainder of ROS negative. Thyroidectomy at St. Mary’s hospital. No record available, patient unsure if total or partial, takes synthroid. Left nephrectomy performed for persistent hematuria (benign mass) BMI 41.

Case Presentation • Social: 2 pack year smoking

• Family: negative • Normal Pap/mammogram (2015)

• Colonoscopy benign polyps (2014)


Physical Exam

• T 97.8° F BP 124/58 HR 80 RR 18 • Gen: AAOx3, NAD • HEENT: well healed thyroidectomy scar, no palpable

masses, no lymphadenopathy, no tracheal deviation • Lungs: clear bilaterally

• CVS: normal S1/S2, no S3, S4, MRG


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Presentation Notes

HR 80 on beta blocker

Labs

9.5

11

33

351

137

4.9

106

23

12

1.0 102

7.0

3.6

24

20

175

0.6

13 30

1.1









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Presentation Notes

Sagittal


Imaging

• CT chest • 4.4 x 4.3 x 6.6cm posterior mediastinal mass, partially

calcified (possible extension from left thyroid) • Mass effect on trachea and esophagus • 3 mm RLL nodule

• CT abdomen/pelvis • 4.8 x 4.5 x 4.6 cm heterogeneous segment 6 liver mass


Further Workup • CEA 1.2 • CA 19-9 33 U/ml • Calcitonin < 2 pg/ml • CA 125 35 U/ml • Thyroxine: 9, T3: 132, TSH 0.3 • Thyroglobulin: 2,250 IU/ml • EUS biopsy: IR biopsy:


Presenter

Presentation Notes

CT surgery, Oncology, IR, GI, and pulmonology consulted

OR • R posterolateral thoracotomy 3rd IC space • Identify/preserve R vagus and phrenic nerve • Ligate azygos vein • Develop plane between trachea and esophagus • Enucleation of mass


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Presentation Notes

Patient in left lateral decubitus


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Presentation Notes

The phrenic nerve lies on the superior vena cava, which is contiguous with the trachea anteriorly The right vagus nerve travels distally obliquely over the trachea to assume a paraesophageal course below the carina.

Post-operative Course

• POD#1-2 Extubated, chest tubes removed

• POD#3-4 diet • POD#5-7 refused (then accepted) rehab


According to the article, which of the following biochemical markers is positively

associated with intrathoracic thyroid malignancy?

A) Calcitonin B) High thyroglobulin C) Low thyroglobulin D) High TSH E) Low TSH


According to the article, which of the following biochemical markers is positively

associated with intrathoracic thyroid malignancy?

A) Calcitonin B) High thyroglobulin C) Low thyroglobulin D) High TSH E) Low TSH


Pathology


Questions?


Posterior Mediastinal Masses • Epidemiology adults vs. children

• Clinical manifestations • Specific presentations and diagnostic tools • Treatments • Summary


Posterior Mediastinum Anatomical Borders

Lateral: Mediastinal pleura Anterior: Pericardium Posterior: T5-T12 vertebrae Roof: Imaginary line from sternal angle and T4 Floor: Diaphragm


Which of the following is NOT part of the posterior mediastinum

A) Azygos vein B) Thoracic duct C) Aortic arch D) Descending aorta E) Esophagus


Which of the following is NOT part of the posterior mediastinum

A) Azygos vein B) Thoracic duct C) Aortic arch D) Descending aorta E) Esophagus


Posterior Mediastinum Anatomy • Descending aorta • Azygos vein • Thoracic duct • Esophagus • Sympathetic chain


Posterior Mediastinum Anatomy • Descending Aorta


Posterior Mediastinum Anatomy • Azygos system of veins


Posterior Mediastinum Anatomy • Thoracic duct


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Presentation Notes

and other lymph nodes

Posterior Mediastinum Anatomy • Esophagus


Posterior Mediastinum Anatomy • Sympathetic chain


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Presentation Notes

As well as the vagus (travel on trachea), phrenic, and splanchnic nerves

Which of the following is the most common posterior mediastinal

tumor in adults? A) Schwannoma B) Neurofibroma C) Ganglioneuroma D) Ganglioneuroblastoma E) Pheochromocytoma



tumor in adults? A) Schwannoma B) Neurofibroma C) Ganglioneuroma D) Ganglioneuroblastoma E) Pheochromocytoma



tumor in children? A) Schwannoma B) Neurofibroma C) Ganglioneuroma D) Ganglioneuroblastoma E) Pheochromocytoma



tumor in children? A) Schwannoma B) Neurofibroma C) Ganglioneuroma D) Ganglioneuroblastoma E) Pheochromocytoma


Epidemiology Posterior Mediastinal Masses

• Adults: 25% posterior, 25% malignant • Children: 50% posterior • Adult: 75% Schwannomas • Children: Ganglioneuroma


Presenter

Presentation Notes

Adults: thymoma and thymic cysts most common primary masses (25% of all mediastinal masses, 50% of anterior masses) Children: neurogenic are most common (40%) Nerve sheath tumors 40-65%

Clinical Manifestations Posterior Mediastinal Masses

• 2/3 asymptomatic • 1/3 symptomatic

• MC chest pain, dyspnea, cough • Malignant > benign

• Dysphagia • Infection • Hormone/biochemical


Presenter

Presentation Notes

Dyspnea: compression of trachea (bronchus or lung parenchyma) Malignant tumors more symptomatology because of invasion and growth rate

Diagnosis of Posterior Mediastinal Masses

• CXR (PA/left lateral)

• Diaphragm fluoroscopy (sniff test)

• *CT chest with contrast*

• +/- MRI to enhance • Hormones and biologic markers

• Histology


Presenter

Presentation Notes

Diaphragm fluoroscopy evaluates paradoxical motion of the diaphragm on rapid inspiration which is indicative of phrenic nerve paralysis. *Test of choice MRI for brachial plexus, great vessels, vertebral body, neural foramina, spinal column Echo/FDG-PET more useful for middle mediastinum and anterior mediastinum (thymoma and thymic carcinoma)

Neurogenic Tumors • Originate from sympathetic ganglia, intercostal

nerves, and paraganglia cells

• Peak incidence adults, mostly benign • Higher prevalence children, greater chance of malignancy


Presenter

Presentation Notes

Sympathetic ganlia (ganglioma, ganglioneuroblastoma, neuroblastoma) Intercostal (neurofibroma, neurilemoma, neurosarcoma) Paraganglia cells (paraganglioma)

Schwannoma • Most common

• 3-5th decade • M=W

• Usually spinal nerve root (sheath)

• Defined capsule, grow slow • Often asymptomatic

• Symptomatic • Pancoast syndrome • 10% spinal column


Presenter

Presentation Notes

Originates from Schwann cells, slow growing Can also arise from thoracic nerve Cause external compression Pancoast syndrome: associated with neoplasm of the superior sulcus of the lung with destruction of the thoracic inlet, brachial plexus, and cervical sympathetic nerves. Triad includes: 1) Shoulder pain radiating to the axilla/scalpula and ulnar distribution of the hand 2) Atrophy of the hand/arm 3) Horner Syndrome (ptosis, miosis, hemianhidrosis, enopthalmos) 4) Blood vessel compression

CXR www.downstatesurgery.org

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Schwannoma: more rounded, adjacent bony remodeling, align themselves with long axis of the cord.

Diaphragm Fluoroscopy www.downstatesurgery.org

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Positive test showing ABSENCE of movement of left diaphragm on inspiration (right picture)

Schwannoma CT www.downstatesurgery.org

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Presentation Notes

Well circumscribed, homogenous, rarely calcification, erosion or splaying of ribs

Schwannoma MRI www.downstatesurgery.org

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Presentation Notes

T2: hyperintense (hypointense in T1) Target sign (central low signal) Split-fat sign: thin peripheral rim of fat on long axis of lesions MRI more sensitive than CT

Schwannoma MRI www.downstatesurgery.org

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Presentation Notes

Classic “Dumbbell” shape: relatively large paraspinal and intraspinal portions connected by a narrow isthmus of tissue traversing the intervertebral foramen

Schwannoma Surgical Principles • Intra-spinal component removed first

• Posterior laminectomy

• Follow with transthoracic approach


Presenter

Presentation Notes

Posterior laminectomy minimizes potential for spinal column hematoma, cord ischemia, and paralysis.

Neuroblastoma • Sympathetic nervous system

• 24 catecholamine once mass found

• 10-20% mediastinum • Most diagnosed prior to 4 years old

• Aggressive, symptomatic • MYCN gene (Chromosome 11)

• Diagnose with CT/MRI • +/- MIBG


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Presentation Notes

Primordial neural crest cells Picked up when already metastatic CT and MRI are similar, avoid radiation with MRI MIBG usually for high risk patients and response to excision Difficult to differentiate from ganglioneuroblastoma, but tend to be lobulated, heterogeneous solid masses. (ganglioneuroblastoma tend to be homogeneous)

Neuroblastoma CT www.downstatesurgery.org

Neuroblastoma Staging • Stage I: removable tumor, (-) LN • Stage IIA: incomplete removal , (-) LN • Stage IIB: complete/incomplete removal, (+) LN • Stage 3: incomplete removal, local spread, (+) LN • Stage 4: incomplete removal, distant spread, (+) LN


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Presentation Notes

International Neuroblastoma Staging system Committee (INSS) International Neuroblastoma Risk Group Staging incorporates image defined risk factors into staging (INRGSS)

Neuroblastoma Treatment • Stage I: Excise • Stage II: Excise and RT • Stage III and IV: Debulk, Chemo/RT

• Planned second look for residual disease


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Presentation Notes

Chemo includes cisplatin, vincristine, doxocubicin, cyclophosphamide, etoposide

Ganglioneuroblastoma • Sympathetic chain origin

• Benign

• Childhood

• CT/MRI

• Well encapsulated, homogeneous • Cystic degeneration

• Treatment: Excision


Presenter

Presentation Notes

Mature and immature ganglion cells

According to Dr. Hammill’s lecture, what percentage of pheochromocytomas are

in the mediastinum? A) 0.1% B) 2% C) 5% D) 20% E) Trumpoma


According to Dr. Hammill’s lecture, what percentage of pheochromocytomas are

in the mediastinum? A) 0.1% B) 2% C) 5% D) 20% E) Trumpoma


Paraganglioma • Neural crest cells

• 1% of mediastinal tumors, 2% of pheochromocytomas

• MC Paravertebral sulcus

• Urine catecholamines

• Diagnosed best with CT and MIBG scintigraphy

• Treatment: surgical resection • Cardiopulmonary bypass when middle mediastinum


Presenter

Presentation Notes

AKA extra-adrenal pheochromocytoma 10% multiple, more common in MEN Associated with Carney’s syndrome: pulmonary chondroma, gastric leiomyosarcoma, and paraganglioma Mets rare

Thyroid tumors • Usually substernal extension goiter

• Connective tissue band with cervical gland • Approach via cervical incision

• 1% totally intrathoracic thyroid tumors

• Heterotropic thyroid tissue • Blood supply from thoracic vessels

• Tracheal/esophageal compression


Presenter

Presentation Notes

Substernal extension goiter 3-17% Intrathoracic thyroid tumors most commonly in anterosuperior mediastinum, and much less likely in middle (between trachea and esophagus) and posterior mediastinum 2-21% malignant

Summary Posterior Mediastinal Masses

• “DATES” • Mostly asymptomatic

• chest pain, dyspnea, cough

• 25% adults, 25% malignant

• Neuroblastoma vs. Ganglioneuroblastoma

• Paraganglioma = extra-adrenal pheochromocytoma

• Thyroid tumors extremely rare • Intrathoracic vs. substernal goiter


References • Mastery of Cardiothoracic Surgery 3rd ed

• Schwartz’s Principles of Surgery 10th ed

• Sabiston 19th ed

• Cameron Current Surgical Therapy 11th ed

• Hegedus, L et al. Approach to Management of the

Patient with Primary or Secondary Intrathoracic Goiter. J Clin Endocrinol Metab,Dec. 2010 95(12):5155-5162.



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Posterior Mediastinal Masses - SUNY Downstate Medical … Mediastinal Masses_mlf.pdfImaging • CT chest • 4.4 x 4.3 x 6.6cm posterior mediastinal mass, partially ... Posterior Mediastinal