Sarcoidosis

Pathology

Sarcoidosis : multi systemic disease of unknown etiology characterized by noncaseating granuloma in many organ & tissue ,
bilateral hilar L.N ,lung involvement or both zeen in chest x ray is the main presenting manifestation ,.Eye & skin involvement seen in 25% of cases .

Etiology & pathogenesis :

Exact etiology is not well known ,could be due to :
Abnormal immune response .
Genetically predispose person.
Epidemiological factors related to bacterial infection.

Morphology :sarcoidosis anywhere produce non caseating granuloma( compose of epitheloid collection with Langhans or foreign body giant cells surround by fibrosis .
In 60% of cases granuloma may show stellate inclusion called asteroid body or may show concentric laminated body compose of calcium & protein called schuman body within giant cell.

Clinically :

Variable from :
1-asymptomatic, discover in routine chest X ray .
2-Pulmonary symptom(cough , Shortness of breath , chest pain)
3-Constitutional symptoms as fever , night sweat , anorexia).
4-lymph adenopathy .
5-hepatospleenomegaly.
6-skin lesion as erythema nodosum.


Lung tumors :
A: Benign tumors : adenoma , hamartoma , lipoma , chondroma
B: Malignant tumors : (primary & secondary )
Primary tumor as Bronchogenic carcinoma , carcinoid, lymphoma, leiomysarcoma .

Bronchogenic carcinoma : It forms 95% of lung tumor. It is the most common tumor in ♂ and in ♀ it come next to breast ca. – 5% rare (carcinoid, lymphoma, leiomysarcoma .

Etiology

The etiology is unknown and several factors blamed:
Cigarette smoking is the most important cause and the risk increase with the increases in the no. of cigarette consuming also it is inversely proportion to the length of cigar stump left and also related to the duration of smoking.

occupational cause: predisposing to asbestose have 5 time risk of developing bronchogenic carcinoma . Other factor include nickel-cobalt-and chrome, these substance Cause gene mutation(cancer.
Cancer may complicate scar in the lung such as scar of infarction or T.B.

Pathology:

It may arise from any site and the prognosis depend on the site of the tumor. It may be:
central (hilar): the tumor arise from the main bronchus seen in 55% of the cases and the bronchial mucosa become ulcerated, rough and nodular. Lymphatic spread are common produce further nodule in the mucosa toward the bifurcation of the trachea, cause narrowing of the affected bronchus(obstruction, so retention of the secretion follow by infection(bronchopneumonia and abscess formation. So the patient seek medical advice early so the tumor is vulnerable for operation so the prognosis is better.
Peripheral type: form 40% of the cases, usually arise from small bronchus which cannot be seen by the naked eye and usually presentation is late.
Bronchoalveolar type: 5% it is a type of mucus secreting adenocarcinoma which use the alveolar wall as the stroma producing condition of the lung similar to pneumonia.

Histological classification:

The who classification include 11 subtype but the most common type are:
squamous cell carcinoma: arise from the main bronchus near the hilum, it usually arise from bronchial epithelium. Which undergo squamous metaplasia, it is related to smooking.
Necrosis and hemorrhage are common and in 2/3 of the cases malignant cell can be seen in the sputum.


Mic: it usually of poorly differentiated type with the formation of intracellular keratin. S.t it may be of well diff. type.

adenocarcenoma:, it arise from the peripheral site of the lung and malignant cell is seen in 50% of cases in the sputum. It has no related to smoking and may complicate scar. It slowly growing tumor but rapidly metastasized.
Mic: alter area, solid carcinoma with mucus secretion, papillary or bronchioalveolar type.

Small cell carcinoma

It is of 3 types, fusiform, polygonal and lymphocyte type (oat cell carcinoma). All arise from the main bronchus near the hilum. It has a relation ship with cigar smoking and it is most aggressive bronchogenic tumors with early metastasis to regional lymph node.

Oat carcinoma compose of small uniform cell slightly larger than lymphocyte with dense round nucleus and very scaly cytoplasm. The cell arranged as a cluster and may show pallisading around the blood vessels or as a rosette. The cell are usually moulded and crushing artificial may seen.

Large cell carcinoma

This tumor compose of sheet of large atypical cell with variation in size and shape with presence of tumor giant cells.

Diagnosis of bronchogenic carcinoma

chest x ray
sputum cytology for malignant cell
bronchoscopic biopsy
lymph node biopsy

effects of tumor

local effect:
bronchial obstruction( collapse
bronchoiectasis
lung abscess
impair drainage of airway ( infections


Para malignant syndrome associated with bronchogenic carcinoma. S.t bronchogenic carcinoma produce endocrine metabolite which is called Para malignant (inappropriate) hormone secretion which can produce the following:

Cushing syndrome seen in oat cell carcinoma due to secretion of ACTH which cause cortical hyperplasia of the adrenal gland lead to increase in cortisole level(Cushing syndrome.
Secretion of antidiuretic hormone also seen in oat cell carcinoma causing retention of Na and H2O.
Hypercalcaemia seen in SCC due to secretion of sub. Similar to parathyroid hormone which cause hypercalcaemia.
Rare syndrome include hyponatremia (decrease Na)-carcinoid syndrome & gynacomastia.
Neuromuscular syndrome include myasthenic syndrome, peripheral neuropathy and polymyositis.
Clubbing of the fingers.
Heamatological manifestation: usually associated with adenocarcinoma include DIC .
Others : as nonbacterial endocarditis and migrating thrombophlebitis.

Spread:

direct: tumor near the hilum of the lung may invade the lung tissue, pericardium and heart causing hemorrhagic pericardial effusion. It may involve the esophagus produce broncho-esophagus fistula, or it may invade the pleura causing pleural effusion.

Tumor in the left side may invade the left recurrent laryngeal n.(hoarseness of voice. While tumor in the apex of the lung which is also called (pancoast) tumor may invade the brachial plexus causing pain and muscle atrophy. Or it may invade the cervical sympathetic chain causing horners syndrome causing myosis( small contracted pupil) proptosis and epsilateral unhydrosis and vasodilatation.

lymphatic spread: the tumor may spread to regional intrapulmonary L.N. ( extra pulmonary hilar L.N. The L.N. may compress the superior vena cava and cause sup. vena cava obstruction syndrome or may compress the trachea causing asphyxia.
Blood spread: it may involve any organ but the most frequent are liver, bone, brain and adrenal gland.

Secondary tumors :

The lung are usually the site of malignant tumor spread either via lymphatic carcinoma of breast or via blood supply and here the lesion present as canon ball metastasis and the primary are usually from renal, testicular or from choriocarcinoma.


Haemoptysis : coughing of blood with the sputum .
Causes :
1- inflammation : as in bronchitis , bronchiectasis , T.b. lung abscess , pneumonia .
2-neoplasm ; primary & secondary lung tumor & adenoma .
3-others : pulmonary thromboembolism , left ventricular failure , mitral stenosis , forein body & bleeding disorders.









 PAGE \* MERGEFORMAT 5