ANTERIOR MEDIASTINAL MASSES Kerunne Kerunne Ketlogetswe ...eradiology.bidmc.harvard.edu/LearningLab/respiratory/Ketlogetswe.pdf · ANTERIOR MEDIASTINAL MASSES Kerunne . Kerunne Ketlogetswe

ANTERIOR MEDIASTINAL ANTERIOR MEDIASTINAL MASSESMASSES

KerunneKerunne KetlogetsweKetlogetsweHarvard Medical School Year IIIHarvard Medical School Year III

Gillian Lieberman, MDGillian Lieberman, MD

MAY 2005

Kerunne Ketlogetswe, MS IIIGillian Lieberman, MD

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INDEX PATIENT: PMINDEX PATIENT: PM

July 2002: 44 July 2002: 44 yoyo otherwise otherwise healthy woman undergoes healthy woman undergoes routine preroutine pre--op testing for op testing for ventral hernia repair, ventral hernia repair, including CXRincluding CXR

PA chest film shows slight PA chest film shows slight increased density over the increased density over the root of the aorta, and root of the aorta, and possibly projected over the possibly projected over the left left hilarhilar areaarea

Left diaphragm elevation Left diaphragm elevation also notedalso noted

Centricity, MGH

PA Chest Radiograph


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PM Lateral Chest PM Lateral Chest XrayXray

Lateral view shows mass in Lateral view shows mass in retrosternalretrosternal space space ieie in in anterior anterior mediastinummediastinum

Radiology recommends Radiology recommends comparison with old films comparison with old films for for chronicitychronicity, and Chest CT, and Chest CT

Successfully undergoes Successfully undergoes operation without operation without complicationscomplications

Centricity, MGH

Lateral Chest Radiograph


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3 YEARS LATER3 YEARS LATER……

Evolution to a 7.5 cm lobulated soft tissue mass; pleural opacities in L paraspinal gutter

Left diaphragm elevated

April 2005: pt presents to ED c/o 2 days anterior April 2005: pt presents to ED c/o 2 days anterior pleuriticpleuritic chest pain, SOBchest pain, SOB

Centricity, MGH


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Chest CTChest CT

Large, Large, lobulatedlobulated anterior anterior mediastinalmediastinal massmass

Internal Internal calcificcalcific focifoci

Also inferior Also inferior extrapleuralextrapleural densities at the left base densities at the left base most consistent with most consistent with thymomathymoma with with extrapleuralextrapleural spread. Other spread. Other possiblilitiespossiblilities include lymphoma or include lymphoma or teratomateratoma..

Centricity, MGH


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WhatWhat’’s in the s in the MediastinumMediastinum??

First, a little anatomy to refresh your First, a little anatomy to refresh your memoriesmemories……


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Contours of the Contours of the MediastinumMediastinum

1 SVC1 SVC

2 Right atrium2 Right atrium

3 IVC3 IVC

4 Aortic arch4 Aortic arch

5 Left pulmonary trunk5 Left pulmonary trunk

6 Left pulmonary artery6 Left pulmonary artery

7 Auricle L atrium7 Auricle L atrium

8 Left ventricle8 Left ventricle

9 L 9 L cardiophreniccardiophrenic angleangleP H Dangerfield, MDhttp://www.liv.ac.uk/HumanAnatomy/phd/mbchb/hrtatk/images/ha1.jpg


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The Anterior The Anterior MediastinumMediastinum

Sternum Sternum anteriorlyanteriorly

Ventral cardiac surface Ventral cardiac surface posteriorlyposteriorly

Contains:Contains:

FatFat

Ascending aortaAscending aorta

Lymph nodesLymph nodes

Internal mammary artery Internal mammary artery & vein& vein

ThymusThymus

Brad H Thomson, MDhttp://www.vh.org/adult/provider/radiology/icmrad/chest/parts/Ant.Med.html


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Middle Middle MediastinumMediastinum

Anterior Anterior mediastinalmediastinal compartment compartment anteriorlyanteriorly

Anterior surface of spine Anterior surface of spine posteriorlyposteriorly

ContainsContains::

Trachea & root of bronchial Trachea & root of bronchial treetree

EsophagusEsophagus

VagusVagus NerveNerve

Recurrent laryngeal nerveRecurrent laryngeal nerve

HeartHeart

Pulmonary arteries and veinsPulmonary arteries and veins

SVC & IVCSVC & IVCBrad H Thompson, MDhttp://www.vh.org/adult/provider/radiology/icmrad/chest/parts/Mid.Med.html


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Posterior Posterior MediastinumMediastinum

Borders the anterior Borders the anterior surface of the spine, surface of the spine, posterior to the ribsposterior to the ribs

Contains:Contains:

Descending aortaDescending aorta

Spine and ribsSpine and ribs

Nerves, roots, spinal Nerves, roots, spinal cordcord

AzygousAzygous & & HemiazygousHemiazygous veinsveins

Brad H Thomson, MDhttp://www.vh.org/adult/provider/radiology/icmrad/chest/parts/Post.Med.html


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ANTERIOR MEDIASTINAL MASSESANTERIOR MEDIASTINAL MASSES

WeWe’’ll focus on the anterior ll focus on the anterior mediastinummediastinum::

Anterior Anterior mediastinalmediastinal masses more likely to be malignant than masses more likely to be malignant than other other mediastinalmediastinal massesmasses

Differential for Differential for MediastinalMediastinal Masses: The 4 TsMasses: The 4 Ts

THYMOMA (20%)THYMOMA (20%)

THYROID (Ectopic)THYROID (Ectopic)

TERATOMA (& OTHER GERM CELL TUMOURS)TERATOMA (& OTHER GERM CELL TUMOURS)

““TERRIBLETERRIBLE”” LYMPHOMALYMPHOMA

Also include Also include mediastinalmediastinal cysts and parathyroid tissue to be cysts and parathyroid tissue to be completecomplete


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Imaging the Imaging the MediastinumMediastinum

How do we evaluate How do we evaluate mediastinalmediastinal masses?masses?

PLAIN FILMS FIRST, PLAIN FILMS FIRST, THEN CT!THEN CT!

CT modality of choiceCT modality of choice-- more sensitive for small more sensitive for small lesions not seen on chest lesions not seen on chest radiographradiograph

Shows infiltration into Shows infiltration into surrounding structuressurrounding structures

Hard to distinguish Hard to distinguish thymicthymic hyperplasia hyperplasia vsvs thymomathymoma

ThalliumThallium--201 201 ScintigraphyScintigraphy allows distinctionallows distinction

PACS, BIDMC

Example of a mediastinal

mass on plain film


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Patient 2: CL A case in pointPatient 2: CL A case in point

63 yo man 5 years s/p Left upper lobectomy for Bronchoalveolar lung cancer, gets routine follow-up chest films and CT

Mediastinal Contours normal… What about his CT?

PACS, BIDMC


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CT Trumps Radiographs!CT Trumps Radiographs!

His chest CT shows soft His chest CT shows soft tissue density tissue density lobulatedlobulated mass in anterior mass in anterior mediastinummediastinum, slowly , slowly growing over 5 yearsgrowing over 5 years

Pt underwent Pt underwent thymectomythymectomy

Pathology showed a Pathology showed a ThymomaThymoma (type B3) with (type B3) with invasion into adjacent lunginvasion into adjacent lung

PACS, BIDMC


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A word on A word on ScintigraphyScintigraphy

Can help distinguish between Can help distinguish between thymicthymic hyperplasia and hyperplasia and thymomathymoma

Pt injected with Pt injected with 201201Tl Chloride; single photon Tl Chloride; single photon emission CT (SPECT) taken at two intervals, early emission CT (SPECT) taken at two intervals, early and delayedand delayedNormal thymus- no increase in thallium uptake

Lymphoid follicular hyperplasia- moderate thallium uptake on delayed images

Thymoma- significant thallium uptake on BOTH early and delayed images


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ScintigraphyScintigraphy would have been useful here:would have been useful here:

21 yo W sudden onset pleuritic SOB

Spiral CT to r/o PE showed 4.7cm soft tissue density anterior mediastinal mass. How do you know what it is?

Underwent thymectomy. Pathology demonstrated benign thymic hyperplasia

Thallium 201 Single Photon Emission CT (SPECT) beforehand could have given better sense of what the lesion was preoperatively PACS, BIDMC


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THYMOMATHYMOMA

Most common primary neoplasm of anterior Most common primary neoplasm of anterior mediastinummediastinum in adultsin adults

Commonly present between ages 30Commonly present between ages 30--5050

50% pts asymptomatic50% pts asymptomatic-- discovered discovered incidentallyincidentally

35% with myasthenia gravis or 35% with myasthenia gravis or paraneoplasticparaneoplastic syndromessyndromes


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THYMOMATHYMOMA

Symptoms due to compression & obstruction of surrounding organs:Symptoms due to compression & obstruction of surrounding organs: CP, CP, cough, cough, dyspneadyspnea, SVC syndrome, SVC syndrome

ParathymicParathymic syndromes: myasthenia gravis, pure redsyndromes: myasthenia gravis, pure red--cell cell aplasiaaplasia, , hypogammaglobinaemiahypogammaglobinaemia, endocrine & connective tissue disorders, endocrine & connective tissue disorders

Myasthenia Gravis 30Myasthenia Gravis 30--50% with 50% with thymomathymoma-- diplopiadiplopia, , ptosisptosis, , dysphagiadysphagia, , weakness, fatigueweakness, fatigue

Pure red cell Pure red cell aplasiaaplasia-- autoimmuneautoimmune--mediated mediated hypoproliferationhypoproliferation of RBC of RBC precursorsprecursors

ThymomasThymomas slow growing, overall 5 yr survival 70%; invasion adverse slow growing, overall 5 yr survival 70%; invasion adverse prognostic markerprognostic marker

Prognosis worsened by invasion through capsule into surrounding Prognosis worsened by invasion through capsule into surrounding fat, fat, pleura, pericardium; pleura, pericardium; intrathoracic/extrathoracicintrathoracic/extrathoracic metastases; metastases; tumourtumour > 10cm; > 10cm; tracheal or vascular compromise; age <30tracheal or vascular compromise; age <30


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DdxDdx of of ThymicThymic MassesMasses

ThymomaThymoma (most common)(most common)

ThymicThymic carcinomacarcinoma

CarcinoidCarcinoid tumourstumours

Germ cell Germ cell tumourstumours

LymphomasLymphomas

ThymicThymic Cysts (rareCysts (rare-- 1% of 1% of mediastinalmediastinal masses)masses)

Definitive diagnosis only via surgical excision and Definitive diagnosis only via surgical excision and histologichistologic identificationidentification


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Radiographic FindingsRadiographic Findings

Contour abnormality of Contour abnormality of anterior anterior mediastinummediastinum

Smoothly Smoothly marginatedmarginated, , often often lobulatedlobulated borders borders against lungagainst lung

Calcification common (in Calcification common (in capsule)capsule)

CTCT

MediastinalMediastinal fat replaced by fat replaced by denser soft tissuedenser soft tissue

Solid, oval or roundedSolid, oval or rounded

http://myweb.lsbu.ac.uk/~dirt/museum/margaret/676-3154-3161230.jpg


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ThymomaThymoma on CTon CT

Paul Stark, MD

http://beta.uptodate.com/application/image.asp?file=pulm_pix/thymoma_.gif~pulm_pix/thymom1.gif


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LYMPHOMALYMPHOMA

Second most common primary anterior Second most common primary anterior mediastinalmediastinal mass in adultsmass in adults

55--10% present with primary 10% present with primary mediastinalmediastinal lesionslesions

HodgkinHodgkin’’s Disease 30ss Disease 30s--40s; Non40s; Non--HodgkinsHodgkins in in all age groupsall age groups

S&S: fever, weight loss, night sweats. S&S: fever, weight loss, night sweats. Compression of adjacent structures rareCompression of adjacent structures rare


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LYMPHOMALYMPHOMA

LobulatedLobulated mass in mass in anterosuperioranterosuperior mediastinummediastinum

Associated regional or Associated regional or distant LADdistant LAD

DxDx made by tissue made by tissue biopsybiopsy

Paul Stark, MDhttp://beta.uptodate.com/application/image.asp?file=pulm_pix/multilob.gif~pulm_pix/hodgkins.gif


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TERATOMATERATOMA

15% anterior 15% anterior mediastinalmediastinal tumourstumours in adults; 24% in in adults; 24% in childrenchildren

Contain tissue from three germ layersContain tissue from three germ layers

EndodermEndoderm-- respiratory & GI epithelium, pancreasrespiratory & GI epithelium, pancreas

MesodermMesoderm-- fat, cartilage, bone, smooth muscle fat, cartilage, bone, smooth muscle

EctodermEctoderm-- predominates. Skin, hair, teethpredominates. Skin, hair, teeth

5050--75% mature cells75% mature cells little malignant potentiallittle malignant potential

Most asymptomaticMost asymptomatic

Expectoration of hair or sebaceous debris Expectoration of hair or sebaceous debris pathognomonicpathognomonic……


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Radiographic findingsRadiographic findings-- TeratomaTeratoma

Mature cystic Mature cystic teratomateratoma in a 31in a 31--yearyear--old man who had old man who had chest discomfort and chest discomfort and dyspneadyspnea at exertionat exertion

Radiograph shows a large, wellRadiograph shows a large, well--defined defined mediastinalmediastinal mass (arrow)mass (arrow)

Jeung et al. Radiographica 2002


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TERATOMA ON CTTERATOMA ON CT

Typical appearance of Typical appearance of mediastinalmediastinal teratomateratoma on on contrast enhanced CTcontrast enhanced CT

Sharply Sharply marginatedmarginated, , round or round or lobulatedlobulated

Heterogeneous density Heterogeneous density including including fatfat, , soft tissuesoft tissue, , calcificationscalcifications

Majority occur in Majority occur in anterior anterior mediastinummediastinum

Jeung et al. Radiographica 2002


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Thyroid in the Thyroid in the MediastinumMediastinum

Extension of Extension of cervialcervial goiter or ectopic goiter or ectopic intrathoracicintrathoracic thyroid tissuethyroid tissue

Diagnosed without biopsy by uptake of Diagnosed without biopsy by uptake of radioactive iodineradioactive iodine


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THYROID GOITERTHYROID GOITER

87 87 yoyo W with known W with known h/oh/o thyroid goiter, stable thyroid goiter, stable over ~10 yrsover ~10 yrs

Large, right superior Large, right superior mediastinalmediastinal density with density with leftward displacement leftward displacement of the of the tracheatrachea

PACS, BIDMC


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THYROID GOITERTHYROID GOITER

CT shows large, CT shows large, intrathoracicintrathoracic goitergoiter extending from the extending from the right lobe of the right lobe of the thyroidthyroid

Causes leftward Causes leftward deviation of the deviation of the tracheatrachea

PACS, BIDMC


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REFERENCESREFERENCES

Cohn, WE. Anterior Cohn, WE. Anterior mediastinalmediastinal mass lesions. mass lesions. UpToDateUpToDate Online 13.1 Online 13.1 http://http://beta.uptodate.com/application/topic.asp?filebeta.uptodate.com/application/topic.asp?file=lung_ca/11795&type==lung_ca/11795&type=A&selecA&selec tedTitletedTitle=1~10=1~10

Higuchi T, Higuchi T, TakiTaki J, J, KinuyaKinuya S et al. S et al. ThymicThymic lesions in patients with myasthenia lesions in patients with myasthenia gravis: characterization with thallium 201 gravis: characterization with thallium 201 scintigraphy.Radiologyscintigraphy.Radiology 2001; 221(1): 2001; 221(1): 201201--6.6.

JeungJeung MM--Y, Gasser B, Y, Gasser B, GangiGangi A et al. Imaging of cystic masses of the A et al. Imaging of cystic masses of the mediastinummediastinum. . RadiographicsRadiographics 2002; 22: S792002; 22: S79--93.93.

MetinMetin M, M, SayarSayar A, A, TurnaTurna A, A, GursesGurses A. Extended cervical A. Extended cervical mediastinoscopymediastinoscopy in the in the diagnosis of anterior diagnosis of anterior mediastinalmediastinal masses. Ann masses. Ann ThoracThorac SurgSurg 2002; 73: 2502002; 73: 250--2.2.

Santana, L., Santana, L., GivicaGivica A., Camacho C. Best cases from the AFIP: A., Camacho C. Best cases from the AFIP: ThymomaThymoma. . RadiographicsRadiographics 2002; 22: 952002; 22: 95--102.102.

TecceTecce PM, Fishman EK, Kuhlman JE. CT evaluation of the anterior PM, Fishman EK, Kuhlman JE. CT evaluation of the anterior mediastinummediastinum: : spectrum of disease. spectrum of disease. RadiographicsRadiographics 1994; 14: 9731994; 14: 973--90.90.


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ACKNOWLEDGEMENTSACKNOWLEDGEMENTS

Drs. Drs. HirotoHiroto HatabuHatabu, Dan , Dan CornfeldCornfeld, Jesse Wei , Jesse Wei and and VaibhavVaibhav KhasigawaKhasigawa for casesfor cases

Larry Larry BarbarasBarbaras, Webmaster, Webmaster

Gillian Lieberman, MDGillian Lieberman, MD

Pamela Pamela LepkowskiLepkowski

Phil Purvis, PACS supportPhil Purvis, PACS support

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ANTERIOR MEDIASTINAL MASSES Kerunne Kerunne Ketlogetswe ...eradiology.bidmc.harvard.edu/LearningLab/respiratory/Ketlogetswe.pdf · ANTERIOR MEDIASTINAL MASSES Kerunne . Kerunne Ketlogetswe