Warung Bebas

Wednesday, 5 October 2011

Pancoast Tumor


 DEFINITION
Pancoast tumors are primary tumors in the lung apex position in one lung, left or right. Known also as a superior sulcus lung tumors, found by Henry Pancoast, a radiologist, in 1932.
Pancoast tumor originating from the upper limit of the lung. The tumor will form an abnormal tissue in the lung apex, which will be more apparent invade the chest wall and surrounding structures, as compared with the structure of the lung itself.



Henry Pancoast

Carcinoma of the lung will lead to superior sulcus Pancoast syndrome is characterized by pain in the shoulder area and spread throughout the nervous ulnar innervation of the arm, atrophy of the arm, Horner's syndrome, as well as compression of the arteries that can be accompanied by edema.
Pancoast tumor to invade surrounding structures such as lymphoid tissue, brachial plexus, the nerve itself intercostalis and ribs, as well as sympathetic nerves are out in the area around the tumor.
Pancoast tumors are most largely by non-small cell Lung (NSLC) with variations by squamous cell carcinoma and adenocarcinoma. Lung Small Cell (SLC) found very little in these tumors (3-5%).

ETIOLOGY
Pancoast tumor risk factors, is the same as the cause of lung cancer in general, such as smoking, exposure to smoke, asbestos and chemicals or other industries.

PATHOPHYSIOLOGY
Mass in the superior sulcus is an extension of lung tumors, which mostly lies outside the lung and involves the chest wall, nerve, lower trunk of the brachial plexus, sympathetic chain, stellate ganglion, ribs, and bones. Most of Pancoast tumors are squamous cell carcinoma or adenocarcinoma. Only 3-5% which is a small cell carcinoma. Carsinoma squamous cells occur more frequently, although the type of cells are large and often undifferentiated. Adenocarcinoma is sometimes found in these locations and can also be a metastasis. Involvement of nerve phrenicus, or reccurens laryngeal nerve or superior vena cava obstruction do not represent a classic picture of Pancoast tumors.


A. Pancoast Tumor, B. Normal Lung

SYMPTOMS
The symptoms produced Pancoast tumors resembling neurogenic diseases and mukuloskeletal so it is not uncommon disease is treated as musculoskeletal diseases such as bursitis. The initial symptoms are usually found is local pain in the shoulder area or region of the scapula, which is close to the vertebrae. Spreading the pain then continues along the ulnar nerve innervation includes the inner arm, elbow, down to the little finger and ring finger (C8). Pain is felt occurred continuously and usually require narcotics to relieve pain. Patients often have to bear with a sore elbow of a healthy hand to reduce the emphasis on the shoulder and upper arm. If the tumor has been on the sympathetic nerve and ganglion stelata it can cause Horner syndrome and anhidrosis on the ipsilateral face. Horner's syndrome is characterized by:
  drooping eyelids (ptosis),
  the absence of sweating (anhidrosis),
  the sinking of the eyeball (enophthalmos),
  and contraction of the pupils (miosis)

The arm can become weak and atrophy and parasthesia. Also, the triceps reflex loss can be encountered. When the tumor spreads to the spinal canal, it can cause compression of the spinal cord that can mimic the symptoms of spinal cord tumor and cervical disc disease. The similarity of symptoms with thoracic outlet syndrome (Thoracic Outlet Syndrome) and cervical disc disease is often encountered at the beginning of clinical symptoms. Paraplegi can occur if the tumor has grown up into the intervertebral foramen. Paraneoplastic syndromes can be found also, but rarely, in patients. Metabolic abnormalities in patients is the result of endocrine secretion from the tumor itself. Manifestations may include Cushing's syndrome, excessive secretion of antidiuretic hormone, hypercalcaemia, myopathy, blood abnormalities, and hypertrophic osteoarthropathy.
Common symptoms of lung cancer such as cough, dyspnea, hemoptysis, and chest pain are not common in patients with Pancoast tumors. Met these symptoms often show that the disease is in advanced stages. Also rare, but can be found in several cases, the emphasis on the recurrent laryngeal nerve resulting in hoarseness and superior vena cava syndrome, which can cause edema of the face, cianosis, and dilated veins in the neck and face.

DIAGNOSIS
How to diagnose this tumor? Very rarely, the examination of sputum cytology in patients can help. At first, Pancoast tumor was diagnosed histologically using the results of transthoracic needle biopsy. Diagnosis through the bronchoscope is not very helpful because most of these tumors are located peripheral.
Examination of the liver, bone, and brain was done to determine the existence of the presence or absence of metastasis. Although more than 90% of patients can be accurately diagnosed based on clinical and radiological findings, biopsy of the tumor for pathological examination can be performed through incisions supraclavicula.
The results of the biopsy needle through the posterior triangle supraclavicula or also managed to confirm the diagnosis and describe the types of cells before treatment.
Although clinical diagnosis is relatively simple, a tissue biopsy is still needed.

STAGING
Staging is determined by the location of the lesion and the metastasis. CT and MRI of the brain tissue is suggested to be done because it is not uncommon metastases to the brain and the diagnosis of lesions in the brain is important in determining tumor staging. Staging can also be obtained from tumor biopsy lymph nodes in the neck
palpable, or it can also be done mediastinoscope. Examination of the bone and liver were also performed to determine the spread of tumors. PET (Positron Emission Tomography) can also be done in helping identifying lymph nodes are affected and how far the spread of cancer.

True Pancoast tumor is usually T3, which describes the expansion of the tumor through the visceral pleura into the parietal pleura and chest wall. Pancoast tumors classified as T4 when mediastinal invasion, cervical invasion, or both has occurred. Peripheral metastasiss is a signal poor prognosis, and surgery is contraindicated in such cases.
Mediastinoscope used to describe the staging of metastases to mediastinal lymph nodes. Mediastinoscope indicated for cervical lesions in the right lung; a Chamberlain procedure (left mediastinoscope interpartial) is indicated for lesions in the left lung. Generally, mediastinoscope performed if the lymph nodes appear larger than 1 cm on CT scans because of the accuracy of the results of CT scans to predict metastatic involvement in enlarged lymph nodes that only 70%. Conversely, if the CT scan did not reveal any enlarged lymph nodes, patients considered to be inoperable. If the nodules in the mediastinum proved positive, then the prognosis is poor. Exceptions to this rule is the upper lobe lesion with positive nodules on the right side of the trachea only. If there is in this segment, the spread is considered local, and the tumor may still be dissected.

Radiography inspection
Radiographic picture


Pancoast Tumor in circle

Checks can be plain images, CT scans, MRI, and arteriogram. Other radiographic examination, such as Bronchoscopy can help evaluate the trachea and bronchial cavities. However, since most of Pancoast tumors formed in the peripheral regions of the lung, bronchoscopy usually does not help physicians in determining diagnoses.
Examination of biopsy can be performed on virtually all disorders. Doctors can make a diagnosis in 95% of patients based on percutaneous needle biopsy, either with the aid of fluoroscopy or guided by CT. Although more than 90% of patients can be  diagnosed correctly based on clinical and radiological findings, an open biopsy of the tumor to the confirmation can be done through a supraclavicular incision. Diagnosis must be very important before continuing treatment of Pancoast tumors. The results of the biopsy needle is also useful in determining the cell type prior to treatment. Although clinical diagnosis is relatively simple, the implementation of  tissue biopsy is always required.

THERAPY
The results of Pancoast tumor therapy is best reported in the form of preoperative irradiation (30 Gy in 10 treatments) and cisplatin and etoposide, followed by resection of the tumor and involved chest wall exposed to 3-6 weeks later. 65% of thoracotomy specimens showed the complete response or minimal residual microscopic disease in the evaluation of pathology. 2-year survival was 55% for all eligible patients and 70% for patients with total resection.

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