Rûta Briedienë, Viktoras Mamontovas68

The purpose of this study was to analyse a correlation among lung can-cer morphology, growth type, localisation and pleura as well as mediastinalinvasion.

Materials and methods. Data on 372 patients have been analysed. Me-diastinal invasion was histologically confirmed in 128 (34.4%) patients. Aortainvasion was confirmed in 21 (5.6%), vena cava superior in 11 (2.9%), pe-ricardium in 55 (14.8%), esophagus in 7 (1.9%), pleural involvement in 54(14.5%), pleural fluid in 51 (13.7%) patients. Chest radiography was perfor-med for all patients, 68 patients underwent chest CT examination.

Results. The probability of mediastinal invasion increases in the cases ofsquamous cell, undifferentiated and small cell carcinomas (p < 0.05). Pleu-ritis and pleural involvement have been found predominantly in adenocar-cinomas.

Using CT findings of possible mediastinal invasion (a 3 cm or more masscontact with the mediastinum, the angle of contact with the aorta more than90°, obliteration of the fat plane between mass and mediastinal structures),the sensitivity of CT identifying mediastinal invasion increases.

Conclusions. Mediastinal and pleural invasion depends on the morpho-logy of cancer. Mediastinal invasion is more common in squamous, undiffe-rentiated and small cell carcinomas. Adenocarcinomas predominantly spreadto the pleura and cause pleural fluid accumulation. CT findings such ascancer mass contact with the mediastinum more than 3 cm and the angle ofcontact with the aorta more than 90° raise CT sensitivity while evaluatingmediastinal involvement. These CT findings could also reflect the operabilityof a process.

Key words: lung cancer, morphology, pleural and mediastinal invasion, ope-rability

Rûta Briedienë,

Viktoras Mamontovas

Diagnostic Radiology Department,Vilnius University Institute ofOncology, Santariðkiø 1,08660 Vilnius, LithuaniaE-mail: rutabried@hotmail.com

Radiological diagnostics of pleura and mediastinuminvasion in lung cancer patients

ACTA MEDICA LITUANICA. 2005. VOLUME 12 No. 2. P. 68–72© Lietuvos mokslø akademija, 2005© Lietuvos mokslø akademijos leidykla, 2005

* Correspondence to: Pavel Elsakov Institute of Onco-logy, Vilnius University, Santariðkiø 1, LT-08660. Vilnius,Lithuania

INTRODUCTION

At the time of presentation, 70% of lung cancer pa-tients have advanced locoregional or metastatic invol-vement, which is considered inoperable (1). An im-portant aim of preoperative staging is to select pa-tients with a localized disease, who may benefit fromsurgery, avoiding unnecessary thoracotomy in otherswith unresectable tumours (2).

TNM classification for bronchogenic carcinoma dis-tinguishes between T3 involvement of mediastinalstructures, which may be resected (mediastinal pleuraor pericardium, mediastinal fat) and T4 tumors, whichinvade the heart, great vessels, trachea, esophagus, and

are usually not resectable (1–4). The involvement ofparietal pleura by a direct tumour extension is classi-fied as T3 and is respectable. CT has shown dispara-te results in evaluating chest wall invasion by tumour.The only highly accurate CT finding with a 100%positive predictive value for chest wall invasion wasbone destruction with or without soft tissue mass ex-tending into the chest wall. There are other CTfindings described in the literature, such as pleuralthickening, the angle between mass and chest wallthat are less accurate indicators of malignant invasion(1, 2). Pleural effusion caused by pleural metastases(T4, unresectable) should be differentiated from a be-nign effusion. In CT scans, malignant effusion is desc-ribed as soft tissue nodularity along the pleural sur-faces, accompanying the effusion (2).

In a study with 80 patients, Glazer (3) representsCT criteria for probable mediastinal invasion in lung

Radiological diagnostics of pleura and mediastinum invasion in lung cancer patients 69

cancer patients, such as mass contact with the me-diastinum more than 3 cm and the angle of contactwith the descending aorta more than 90°. However,these criteria were not reliable signs of either inva-sion or respectability.

Patient survival rate after T3surgical treatment is 36%, while itreaches only 12% in patients withT4 lesions (1). The operability andsurvival rate in patients with me-diastinal invasion are considerablyworse than in patients with chestwall and ribs involvement (5).

Not only the stage but also lungcancer morphology determines po-stoperative survival: Martini et al.(5) state that in patients with T3

lesions the postoperative survival rate is 23% in ade-nocarcinomas and 12% in squamous cell carcinomas.Kirsch and Sloan report that the postoperative survi-val rate reaches 34% in squamous cell carcinomasand 12% in adenocarcinomas (6). Less attention inthe literature is paid to the influence of morphologyon cancer intrathoracic spread differences, so in ourwork we wanted to analyse possible correlations bet-ween lung cancer morphology and intrathoracic spre-ad.

The purpose of the work was to analyse a corre-lation between lung cancer morphology, growth type,localisation as well as pleural and mediastinal inva-

sion.One of the goals was to estima-

te the sensitivity and specificity ofradiologic diagnostic methods whileevaluating lung cancer invasion topleura and mediastinum.

MATERIALS AND METHODS

Data on 372 patients operated onfor lung cancer were analysed. Me-diastinal direct invasion (T3, T4) wasconfirmed in 128 (34.4%), invasionof aorta in 21(5,6%), vena cava su-perior in 11 (2.9%), pericardium in55 (14.8%), esophagus in 7 (1.9%)of these patients. Pleural fluid wasconfirmed in 51 patients, pleural me-tastases in 28 patients, direct pleu-ral invasion in 26 patients, rib de-struction in 17 and thoracic wall le-sion in 20 patients.

Anterior and lateral chest radio-grams were performed for all pa-tients and CT for 68 patients.

All lung cancers according togrowth type were divided into cen-tral, peripheral and disseminated.

According to morphological classification, they we-re divided into the main groups: 200 (53.7%) squ-amous cell carcinomas (SCC), 90 (24.2%) adeno-carcinomas, 5(1.3%) bronchoalveolar carcinomas,17(4.6%) undifferentiated carcinomas, 7 (1,9%)

57%

15%8%

2%

18%

37%

22%

59%

29%

55%

SCC AdenoUndif LCC SCLC

among mediastinal invasion among every morphology

Fig. 1. Correlation of lung cancer morphology with direct mediastinal invasion

6%2%

12% 14%

52%

10% 10%

28%

SCC Adeno Undif SCLC

among every morphology among aorta invasion

Fig. 2. Correlation of aorta invasion with lung cancer morp-hology

4% 3%

14%

64%

27%

9%

SCC Adeno LCC

among every morphology among v.cava superior invasion

Fig. 3. Correlation of vena cava superior invasion with lung cancer morphology

17%10%

6%

24%

64%

16%

2%

18%

SCC Adeno Undif SCLC

among every morphology among pericardium invasion

Fig. 4. Correlation of pericardium invasion with lung cancer morphology

Rûta Briedienë, Viktoras Mamontovas70

large cell carcinomas (LCC),42 (11.3%) small cell carcino-mas (SCLC), 3 (0.8%) ade-nosmall cell carcinomas and 8(2.2%) adenosquamous carci-nomas.

All the data were processedwith Progfreq and Proc logisticstatistical programs.

RESULTS

The diagrams represent data onlung cancer morphology corre-lation with lung cancerintrathoracic invasion.

A statistically based correla-tion between lung cancer me-diastinal invasion and squamouscell morphology were estimated(p = 0.0003); undifferentiatedand small cell carcinomas pre-dominated amongst mediastinalinvasion (p < 0.05).

Squamous cell morphologypredominated in aorta invasion(52%), but it was commonamongst undifferentiated (12%)and small cell carcinomas(14%).

Amongst vena cava superiorinvasion, squamous cell carcino-mas were more common. A sta-tistically based correlation wasestablished between vena cavasuperior invasion and cancer lo-calization in the right upperlung lobe (p = 0.0008).

Pericardium invasion wasmore common in squamous cellcarcinomas (64% among peri-cardium invasion and 17%among squamous cell morpho-logy), but was also commonamong small cell carcinomas(24%).

Pleural invasion was presentin adenocarcinomas (p =0.0003), both amongst pleuralinvasion and in different morp-hology groups.

Pleural fluid was more of-ten confirmed in adenocarcino-mas (p < 0.0001).

A statistically based correla-tion between central carcinomagrowth and mediastinum invol-vement (ð < 0.001), esophagus

38%

52%

2% 4%10%

30%

6% 5%

SCC Adeno Undif SCLC

among pleura invasion among every morphology

Fig. 5. Correlation between pleura involvement and lung cancer morphology

25%

57%

6%12%

6%

32%

2%14%

SCC Adeno Undif SCLC

among pleuritis among every morphology

Fig. 6. Correlation between pleural fluid and lung cancer morphology

Picture 1. Mediastinal pleura adhesionis observed near the heart shadow. Inva-sion of pericardium was confirmed

Picture 2. Tight contact between cancermass and mediastinum is observed. Ino-perable lesion of mediastinum and aortawas confirmed

Picture 3. More than 3 cm cancer mass contact with mediastinum is observed.Inoperable mediastinal invasion was confirmed

Radiological diagnostics of pleura and mediastinum invasion in lung cancer patients 71

(p = 0.0437) and pericardium (p = 0.0248) was es-tablished. Peripheral carcinomas more often invol-ved parietal pleura (p < 0.0001) and chest wall (p= 0.008).

DISCUSSION

Conventional radiography is not adequate for detec-ting mediastinal or pleural invasion although our ob-servations show that a right contact between cancermass and mediastinum shadow indicate mediastinalinvasion (Pictures 1, 2). The sensitivity of the radio-graphic method rose form 4% to 16%.

While evaluating mediastinal invasion signs on CTscans, such as mediastinal fat obliteration, mass ef-fect or deformity of mediastinal structures, its sensi-tivity was 33% specificity 97%. Using CT findingsuch as cancer mass contact with mediastinum morethan 3 cm (3, 8), the sensitivity of CT rose up to57% and the specificity was 94%.

Picture 4. More than 3 cm cancer mass contact with me-diastinum is observed. Although a dark demarcation lineis seen between the mass and the pericardium, pericardialand mediastinal inoperable involvement was determined

Picture 5. More than 90° of mass contact with aorta is observed. Inoperable lung cancer with aorta invasion wasconfirmed

Picture 6. Peripheral carcinoma with chest wall invasionand bone destruction is observed. Mass contact with pleu-ra is more than 3 cm

CT sensitivity determining descending aorta in-volvement was 14% and specificity 100%. In caseswhere the mass abutted the descending aorta wall,with the total aortic circumference as 360°, the con-tact was graded as less than 90° or 90° and greater.Descending aorta involvement was suspected whenthe angle of contact with the aorta was more than90° (3). Using this finding the sensitivity of CT was57% and the specificity 95%.

According to different authors, CT sensitivity eva-luating lung cancer mediastinal invasion may rangebetween 51–100% and specificity from 60 to 100%(1, 2, 6, 7).

Only 15 patients (12%) from 128 with mediasti-nal invasion underwent complete resections (9 ofthem had a T3 process). All the patients with CTfindings such as mass contact with the mediastinummore than 3 cm and the angle of contact with thedescending aorta more than 90° had technically un-resectable masses. Consequently, these findings could

Rûta Briedienë, Viktoras Mamontovas72

be used also for process operability prevision, alt-hough Glazer (3) states that these findings not ne-cessarily indicate an inoperable process.

Evaluating pleural fluid, CT sensitivity was 82.35%and specificity 100%; the sensitivity and specificityof the radiographic method was 47% and 100%, res-pectively. Metastatic pleura involvement (pleural car-cinosis) was not diagnosed on radiographs or CT.Chest sonography may be of great value in such ca-ses (2). Direct pleural invasion is unquestionable inthe case of bone destruction. If the mass contactwith the pleura is more than 3 cm, parietal pleuralinvasion may be suspected (1, 2).

A statistically based correlation (p < 0.05) betwe-en mediastinal invasion and cancer localization in thelung depended on topographically closest mediastinalorgans, for example, the between pericardium invol-vement and right middle lobe cancer, v. cava superiorinvolvement and right upper lobe cancer localization,etc.

CONCLUSIONS

1. Mediastinal and pleural invasions depend onthe morphology of cancer. Mediastinal invasion ismore common in cases of squamous, undifferentia-ted and small cell carcinomas. Adenocarcinomas pre-dominantly spread to the pleura and cause pleuralfluid collection.

2. Central lung carcinomas tend to invade me-diastinal organs more often than do peripheral car-cinomas.

3. CT findings such as cancer mass contact withthe mediastinum more than 3 cm and the angle ofcontact with the aorta more than 90° raises CT sen-sitivity while evaluating mediastinal involvement.

4. These CT findings could also reflect processoperability.

5. A light contact between the cancer mass andthe mediastinum shadow in conventional radiographsmay indicate mediastinal invasion.

Received 5 November 2004Accepted 15 March 2005

References

1. Pass Harvey I, Mitchell James B, Johnson David H.Lung Cancer: Principles and practice. Lippincott-Ra-ven Publishers, Philadelphia, 1996: 437–70.

2. Vansteenkiste J, Bittner R, Izbicki J et al. Evolvingtechniques in the staging of lung cancer. Eur RespirRev 2002; 12: 141–55.

3. Glazer Harvey S, Kaiser LR, Anderson DJ et al. In-determinate mediastinal invasion in bronchogenic car-

cinoma: CT evaluation. Radiology 1989; 173: 37–42.4. Macchiarini P, Chapelier AR, Monnet I et al. Exten-

ded operations after induction therapy for stage IIIB(T4) non-small call lung cancer. Ann Thorac Surg 1994;57: 966–73.

5. Martini N, Yellin A, Ginsberg R et al. Management ofnon-small cell lung cancer with direct mediastinal in-volvement. Ann Thorac Surg. 1994; 58: 1447–51.

6. Slawson RG. Mediastinal lung cancer: answers and qu-estion. Southern Medical Journal 1994; 87(6): 646–52.

7. Àêîïîâ ÀË, Áîáðîâ ÅÈ. Ýôôåêòèâíîñòüêîìïüþòåðíîé òîìîãðàôèè ïðè ìåñòíî-ðàñïðîñòðàíåííîì íåìåëêîêëåòî÷íîì ðàêåëåãêîãî. Âîïðîñû îíêîëîãèè 2001; 47(5): 580–3.

8. Lee JKT, Sagel SS, Stanley Robert J. Computed BodyTomography. Raven Press. New York 1983; 55–130:535–46.

Rûta Briedienë, Viktoras Mamontovas

PLEUROS IR TARPUPLAUÈIO PAÞEIDIMORADIOLOGINË DIAGNOSTIKA SERGANT PLAUÈIØVËÞIU

S a n t r a u k aTyrimo tikslas buvo nustatyti koreliacijà tarp plauèiø vëþiomorfologinio tipo ir iðplitimo krûtinës làstoje poþymiø.

Medþiaga ir metodai. Iðanalizuoti 372 pacientø, operuotødël plauèiø vëþio, duomenys. Tarpuplauèio ir jo organø paþei-dimas nustatytas 128 (34,4%) pacientams, pleuros paþeidimas– 54 (14,5%) pacientams, pleuritas – 51 (13,7%) pacientui.Aortos peraugimas nustatytas 21 (5,6%), virðutinës tuðèiosiosvenos paþeidimas – 11 (2,9%), perikardo – 55 (14,8%), stem-plës – 7 (1,9%) pacientams. Visiems pacientams prieð opera-cijà atliktos krûtinës làstos rentgenogramos, 68 pacientams at-liktos krûtinës làstos kompiuterinës tomogramos (KT).

Rezultatai. Tarpuplauèio paþeidimas buvo patikimai daþ-nesnis nediferencijuotø, smulkialàsteliniø ir plokðèialàsteliniøkarcinomø atveju. Tarp adenokarcinomø vyravo pleuros vë-þinis paþeidimas ir pleuritas (p < 0,05). KT metodo jautru-mas ir specifiðkumas nustatant plauèiø vëþio iðplitimà á tar-puplauèio organus padidëja naudojant ðiuos vertinimo kri-terijus: darinio kontaktas su tarpuplauèiu didesnis nei 3 cm,darinio kontaktas su nusileidþianèiàja aorta sudaro daugiaunei 90° jos apskritimo.

Išvados. Tarpuplauèio ir pleuros paþeidimas priklausonuo plauèiø vëþio morfologinio tipo. Tarpuplauèio paþeidi-mas bûdingesnis nediferencijuotoms, smulkialàstelinëms irplokðèialàstelinëms karcinomoms. Adenokarcinomoms la-biau bûdingas pleuros paþeidimas bei pleuritas. KT stebintdidesná nei 3 cm darinio kontaktà su tarpuplauèiu ir kon-taktà su aorta, sudarantá daugiau nei 90° jos apskritimo, ga-lima átarti ðiø struktûrø peraugimà.

Raktaþodþiai: plauèiø vëþys, pleuros, tarpuplauèio paþei-dimas