Pancoast Syndrome

What is Pancoast Syndrome?

Pancoast syndrome represents malignant tumor in lungs. The site specific location of the tumor is a classic feature of Pancoast syndrome. The tumor can grow either in the superior sulcus of the left or right lungs and the site of the location is at the extreme apex (very top)¹. The malignancy easily spread to adjoining tissue from the apex of the lungs. The abnormal patch becomes prominent in the chest wall. The malignancy of Pancoast syndrome mainly merge with following structures²:

• Lymphatic vessels
• Brachial plexus (cervical nerves group together and form this)
• Intercostal nerves (a nerve between a pair of adjacent ribs)
• Stellate ganglion (Ganglion are the meeting junction of two or more nerve cells)
• Sympathetic chain (The chain are made of sympathetic nerves, which are distributed from spinal column)
• Adjacent ribs
• spinal discs

Staging

Carcinogenic tumors are staged by three different phase – Tumor, Node and Metastasis (TNM). Pancoast tumors are presented as a T3 stage. In this stage pleura and the brachial plexus become invaded³.

Sign and Symptoms

The most common symptom of Pancoast Syndrome is Shoulder pain. The pain initiation started with invading the tumor into nearby structures⁴. This includes:

• The adjoining ribs
• The brachial plexus or the branch of the nerve fibers that pass through downward from the vertebrae
• The outermost layer of the lungs or parietal pleura
• The endo thoracic fascia or a fibrous tissue detaches the chest wall from the diaphragm and the pleura

The gradual progression of the metastasis causes pain extension, which radiates from arm to shoulder blades and then extends to the upper back. Pain even feel in armpit due to spreading of Pancoast tumor into scalene muscles.

The following clinical manifestations are found in Pancoast Syndrome³:

• Cervical sympathetic plexus is invaded by an ipsilateral invasion; which leads to Horner’s syndrome; a 14-50% of patients have miosis, enophthalmos, ptosis (the classic features of Horner’s syndrome).
• Not always, but sometimes Ipsilateral reflex sympathetic dystrophy may occur.
• Invasion occurs in brachial plexus (C8-T2) and causes shoulder and arm pain. This can cause carnage of the basic hand muscles and paraesthesiae in the medial side of the arm.
• Rarely, the carnage of the intrinsic hand muscles and paraesthesiae in the medial side of the arm.
• In a rare instance, horse voice with or without a bovine cough developed due to repeated laryngeal nerve palsy can cause unilateral vocal cord paralysis, and/or phrenic nerve involvement.
• Compression of blood vessels in the arm can cause secondary edema development.

Causes

• Some adjoining malignancy such as breast cancer, lymphoma or plasmacytoma, mesothelioma, or metastatic carcinoma – eg, from the larynx, thyroid, colon, bladder or cervix.
• Pancoast’s syndrome due to non-neoplastic reason is rare.
• Some bacterial infections like tuberculosis, pneumonia (staphylococcal or pseudomonas) and hydatid disease very rarely can initiate the Pancoast’s syndrome.
• Exceptionally disseminated nocardiosis, mycotic aneurysm and plasma cell granulomas can cause Pancoast’s syndrome.
• Some document reported that other diseases like a cervical rib, non-Hodgkin’s lymphoma, and pulmonary amyloidosis can associate with Pancoast’s syndrome.

Diagnosis

The following are diagnostic tools available for detecting Pancoast’s syndrome.

• CXR and CT scan for lungs and abdomen
• Positron emission tomography (PET)
• MRI is conducted as pre-operative process to review structures at the thoracic inlet
• Brain CT or MRI is conducted to check spreading of metastases
• Percutaneous method applied for biopsy test

Management

The life-threatening condition occurs because Pancoast’s tumor involves crucial structures at the thoracic inlet. The traditional approach of managing Pancoast’s tumor is resection of brachial plexus, but this process leads to paralysis and neuropathic pain, which is clinically not acceptable. In modern days, the management of Pancoast’s tumor is multifaceted, which includes

• Chemoradiotherapy (usually cisplatin-based)
• Wedge resection
• Lobectomy

Prognosis

Pancoast’s tumor has a poor prognosis due to association with vertebrae, cervical plexus and lymph nodes. The life expectancy of detecting the Pancoast’s tumor is maximum 5 years for complete resection and without involving lymph node and i.e. 30 to 40%. Less than 10% survival rate is common for all other groups. Even the chance of recurrence occurs in 2/3rd of the patients.

Recent successful implementation of chemoradiation and resection provides a better prognosis, like approximately five years survival rate exceeded to 50-70%. But the Mediastinal lymph node association provides a poor prognosis.

References

1. Karl J D’Silva (2014); Pancoast Syndrome; Medscape; Retrieve from: http://emedicine.medscape.com/article/284011-overview
2. Shabir Bhimji; Pancoast Tumor; Retrieve from: http://www.emedicinehealth.com/pancoast_tumor/article_em.htm
3. Pancoast’s Syndrome; Patient; Retrieve from: http://patient.info/in/doctor/pancoasts-syndrome
4. Pancoast Tumor Symptoms; MOFFITT Cancer Center; Retrieve from: https://moffitt.org/cancers/pancoast-tumor/signs-symptoms/