Mesothelioma

A. Benign Pleural Fibroma:

-Pathology:

· Age: 40 years (but children are reported too)

· Size: small discovered accidentally à large & producing symptoms

· Shape: spherical, lobulated, well encapsulated, surrounded by compressed lung tissue

· Site: from any site in the pleural surface (visceral or parietal), connected to the pleura with a pedicle or broad base

· L/M: interlaced fibrous tissue + myxomatous degeneration + mesothelial cells or sub-mesothelial mesenchymal cells (pleomorphism with few mitotic cells)

-Clinical Picture:

.Symptoms:

· Asymptomatic

· General: fever, chills, hypoglycemia, clubbing up to osteoarthropathy (all are reversible after surgery).

· Local: symptoms of pressure à progressive dyspnea or pleuritic chest pain

.Signs:

· May mimic pleural effusion à displace mediastinum

· May mimic pericarditis (constrictive type) due to gross mediastinal displacement

-Behavior:

· Simple for a long time

· Invasive (especially after surgical resection) à Anaplastic Fibrosarcoma

· Recurrence (suspected with return of constitutional symptoms)

-Investigations:

1. CXR: appears as a dense homogenous, spherical and lobulated opacity anywhere in the pleura (if in fissure appears ovoid) ± seen with a connection to the pleura by a pedicle or broad base.

2. Biopsy: see pathology.

-Treatment:

Surgical resection as it's a potentially malignant disease (no lung tissue removed).

B. Malignant Mesothelioma:

-Definition:

It's a cancerous proliferation of mesothelial cells that usually involves a large extent of the pleural cavity.

-Etiology:

· Asbestos exposure (major risk factor of 80%) à occurs with crocidolite more with latent period of 30-45 yrs.

· Erionite fiber mineral exposure (more in Turkey).

· Chest wall irradiation (very rare non-industrial cause).

-Pathology:

Mixed	Sarcomatous	Epithelial (Tubulopapillary)	Undifferentiated polygonal type
1 :	1 :	2	----
Easiest to diagnose as it's a metastasis from a tumor with histological elements (LN, Bone …etc)	Cellular fibro-sarcoma with myxoma & acellular collagen	Similar to 2ry adenocarcinoma with regularly ordered cells ± dust or carbon, nuclei are vesicular with no mitosis, dilated acini appears as branching fronels lined with cuboidal cells	Sheets of polygonal or solid epithelial cells
Asbestos bodies seen in the underlying lung tissue supports the diagnosis

-Staging:

Stage I: Ipsilateral only à lung, parietal pleura, pericardium, diaphragm.

Stage II: Local invasion à chest wall, heart, LNs & esophagus.

Stage III: Penetrates diaphragm à peritoneum, opposite pleura, LNs out.

Stage IV: Distant metastasis.

-Clinical Picture:

.General: cachexia, fever, rarely clubbing & rarely LN⁺⁺

.Local: Signs of pleural effusion + frozen mediastinum (more) or shift to the contralateral side (rare with massive effusion) à shift of the mediastinum to the same side (with marked pleural encasement).

-D.D.:

1. Metastatic adenocarcinoma: differentiated by immuno-histochemistry, CEA, B₁ specific glycoprotein.

2. Benign asbestos pleural effusion: occurs in the 1^st 20 yrs of exposure, small, asymptomatic and needs only follow-up.

3. Benign fibrous mesothelioma (pleural fibroma): see before.

4. Pleural thickening or fibrosis: see later.

-Investigations:

1. Radiology:

a) CXR:

· Large pleural effusion: earliest picture (absent in 20% of cases, can be bilateral in < 5%).

· Pleural thickening: irregular pleura.

· Pleural nodules: unilateral.

· Asbestos related plaques, calcifications, & parenchymal fibrosis.

· Spread later: pericardial effusion, mediastinal widening, and rib destruction.

b) CT chest:

· Pleural nodular thickening and encasement later.

· Pleural effusions.

· Pleuro-pulmonary changes in the opposite hemithorax.

· Evidence of local spread.

2. Functions:

a) Spirometry: progressive restrictive pattern

b) ABG: normal up to respiratory failure

3. Thoracocentesis:

a) Chemical:

· Exaudative

· Low PH

· Low glucose

· High hyaluronic acid concentration (viscid fluid).

b) Physical: straw colored, sero-sanguinous or hgic fluid.

c) Cytological: +ve for malignancy in 10% of cases.

4. Biopsy:

a) Closed: by Abram's needle (non-diagnostic small insufficient)

b) Open: diagnostic

c) VATS: useful early

-Treatment:

-Curative treatment: None

-Palliative treatment:

· Surgery (with high mortality rate so it's not done): extrapleural pneumonectomy, pleurectomy & decortication, limited pleurectomy, or thoracoscopy with talc powdrage.

· Radiotherapy: with some regression and lowering fluid accumulation.

· Chemotherapy (single agent): Adriamycin or Cyclophosphamide.

· Analgesics, palliative thoracocentesis & pleuredesis, O₂ & prednisolone (decreases fever and sweating).

*Pleural Thickening or Fibrosis:

-Definition:

It's a diffuse process involving parietal and visceral layers of pleura with infrequent involvement of the surface of the lung.

-Etiology:

.Localized type: as a sequence of exaudative pleural effusion of any cause

.Generalized type:

Unilateral	Bilateral
-TB effusion -Old artificial pneumothorax -Hemo-thorax -Empyema	-Asbestosis -Rheumatoid disease -SLE -Drugs (methyrgide, proctalol)
With Calcification	Non Calcified except asbestosis

-Clinical Picture:

· History of pleural effusion, asbestos exposure.

· Asymptomatic à if unilateral with no lung disease.

· Exertional dyspnea à if extensive bilateral.

· Chest pain (v rare) à suspect tumor not fibrosis.

-Investigations:

1. CXR:

· Localized thickness in the lower zone with obliteration of CP-angle.

· Streaky irregular infiltrations.

· Diffuse thickening.

· Thickening + nodular picture à suspect cancer or mesothelioma

· Atelectasis can be found.

· Calcifications can be seen.

2. CT chest: Done when:

· Mesothelioma is suspected.

· See if there is an underlying lung disease.

· Before surgery.

3. PFT:

· Restrictive pattern

· Normal DLCo

· Low Compliance

-D.D.: from malignant infiltration of mesothelioma.

-Treatment:

.Of the cause

.Pleurectomy & decortication:

· In localized type: only if there is restriction

· In diffuse type: with pre-operative assessment of underlying lung disease, persistent disability, hazards of the procedure & lung functions.

*Download from: Mesothelioma.doc

Bronchogenic Carcinoma

Staging of NSCLC:

Primary tumor
TX	primary tumor cannot be evaluated, or tumor proven only by the presence of malignant cells in sputum or bronchial washings but not visualized by imaging or bronchoscopy
T0	no evidence of primary tumor
Tis	carcinoma in situ
T1	tumor < 3 cm, surrounded by lung or visceral pleura, without bronchosopic evidence of invasion proximal to the lobar bronchus
T2	tumor > 3 cm, or tumor of any size with one or more of the following characteristics: - infiltration of the visceral pleura - invades the main bronchus but > 2 cm distal to the main carina - atelectasis or obstructive pneumonitis that extends to the hilus but does not involve the entire lung and without pleural effusion
T3	tumor of any size with invasion of the chest wall including adjacent rib(s), diaphragm, mediastinal pleura, parietal pericardium, or tumor in the main bronchus < 2 cm distal to the carina; or tumor associated with atelectasis or obstructive pneumonitis of the entire lung
T4	tumor of any size that invades the heart, great vessels, trachea, carina, esophagus, vertebral body; or tumor with malignant pleural effusion, or separate tumor nodules in the same lobe as the primary tumor
Regional lymph nodes
NX	lymph node status cannot be evaluated
N0	no evidence of regional lymph node metastasis
N1	metastasis to ipsilateral peribronchial and/or ipsilateral hilar lymph nodes, including direct invasion
N2	metastasis to ipsilateral mediastinal and/or subcarinal lymph nodes
N3	metastasis to contralateral mediastinal, contralateral hilar, or ipsilateral and/or contralateral supraclavicular or scalene lymph nodes
Distant metastasis
MX	distant metastasis cannot be evaluated
M0	no evidence of distant metastasis
M1	distant metastasis, including separate tumor nodules in a different lobe (ipsilateral or contralateral)

Stage groupings based on TNM classification

occult carcinoma	TX	N0	M0
stage 0	Tis	N0	M0
stage IA	T1	N0	M0
stage IB	T2	N0	M0
stage IIA	T1	N1	M0
stage IIB	T2 T3	N1 N0	M0 M0
stage IIIA	T1 T2 T3	N2 N2 N1,N2	M0 M0 M0
stage IIIB	any T T4	N3 any N	M0 M0
stage IV	any T	any N	M1

Karnofsky scale:

Able to carry on normal activity and to work; no special care needed.	100	Normal no complaints; no evidence of disease.
	90	Able to carry on normal activity; minor signs or symptoms of disease.
	80	Normal activity with effort; some signs or symptoms of disease.
Unable to work; able to live at home and care for most personal needs; varying amount of assistance needed.	70	Cares for self; unable to carry on normal activity or to do active work.
	60	Requires occasional assistance, but is able to care for most of his personal needs.
	50	Requires considerable assistance and frequent medical care.
Unable to care for self; requires equivalent of institutional or hospital care; disease may be progressing rapidly.	40	Disabled; requires special care and assistance.
	30	Severely disabled; hospital admission is indicated although death not imminent.
	20	Very sick; hospital admission necessary; active supportive treatment necessary.
	10	Moribund; fatal processes progressing rapidly.
	0	Dead

*For Full Text --> Download: Bronchogenic Carcinoma.pdf