Makindo Medical Notes

About

• A Pancoast tumour, also known as a superior sulcus tumour, is a form of lung cancer that arises at the apex (top) of the lung. These tumours are often associated with significant local invasion and can cause ipsilateral Horner's syndrome and shoulder pain.
• Most commonly associated with non-small cell lung carcinoma (NSCLC), particularly squamous cell carcinoma and adenocarcinoma.

Structures Invaded by Pancoast Tumor

• Lung Apex: The tumour begins in the apex of the lung and infiltrates adjacent structures.
• Brachial Plexus (Lower Roots): Involvement of the lower roots (C8, T1) of the brachial plexus can lead to pain, weakness, and muscle wasting in the arm and hand.
• Sympathetic Plexus: Involvement of the sympathetic chain leads to Horner's syndrome (ptosis, miosis, anhidrosis).
• Chest Wall and Rib Destruction: In advanced stages, the tumour may invade the chest wall, ribs, and adjacent vertebrae, causing significant pain and structural damage.
• Recurrent Laryngeal Nerve: Compression of this nerve can cause hoarseness and a characteristic "bovine cough" (weak, non-explosive cough due to vocal cord paralysis).

Clinical Features

• Shoulder Pain and Weakness: Often the first symptom, caused by invasion of the brachial plexus, and is frequently misdiagnosed as musculoskeletal pain.
• Cough, Haemoptysis, Weight Loss: Common lung cancer symptoms that may also be present, especially in advanced disease.
• Horner's Syndrome: Involvement of the sympathetic chain causes a classic triad of miosis (constricted pupil), enophthalmos (sunken eye), ptosis (drooping eyelid), and anhidrosis (loss of sweating) on the same side as the tumour.
• Recurrent Laryngeal Nerve Involvement: Leads to hoarseness and a characteristic "bovine cough" due to vocal cord paralysis.
• Additional Findings: Look for signs of systemic illness, including digital clubbing, nicotine staining on the fingers, cachexia (weight loss and muscle wasting), and evidence of metastasis.

Left Pancoast Tumor with Horner's Syndrome

This image demonstrates a patient with a left-sided Pancoast tumour and Horner's syndrome. Horner's syndrome often presents with less pronounced ptosis, but other signs, such as miosis and anhidrosis, are typically visible.

Investigations

• Chest X-Ray (CXR): An apical lesion on the corresponding side of the suspected Pancoast tumour may be seen. The lesion is usually subtle, and careful evaluation of the lung apex is required.
• U&E (Urea and Electrolytes): Investigate for signs of SIADH (syndrome of inappropriate antidiuretic hormone secretion) or dehydration due to hypercalcaemia. Look for low sodium (hyponatremia) if there are adrenal metastases.
• Bone Profile: Elevated calcium levels (hypercalcaemia) can indicate bone metastasis or paraneoplastic syndrome associated with the tumour.
• Liver Function Tests (LFTs): Raised alkaline phosphatase (ALP) may suggest metastatic disease to the liver or bone.
• CT Chest: A CT scan of the chest provides detailed imaging to confirm the presence and extent of the tumour, its invasion of adjacent structures, and the potential for metastases.
• Bronchoscopy: May be used to visualize the tumour and obtain tissue biopsy samples for histological diagnosis.
• Sputum Culture and Sensitivity: Useful in identifying potential infectious complications and to differentiate between cancer-related symptoms and infection.

Management

• Bronchogenic Carcinoma Treatment: As Pancoast tumours are typically a type of bronchogenic carcinoma, the treatment follows similar principles. However, due to their local invasion, Pancoast tumours are usually not resectable.
• Pain Control and Palliation: Because surgery is often not an option, effective pain management and palliative care are critical. Opioid analgesics, nerve blocks, or radiotherapy may be used to control pain from brachial plexus invasion or chest wall involvement.
• Radiotherapy: May be used to shrink the tumour, relieve local symptoms, and improve the patient's quality of life.
• Chemotherapy: Systemic chemotherapy may be administered to control tumour growth and manage metastases, especially in non-small cell lung cancer.
• Multidisciplinary Care: Involvement of oncologists, pulmonologists, radiotherapists, and palliative care teams is essential to provide comprehensive care for patients with advanced Pancoast tumours.

Prognosis

• Pancoast tumours have a poor prognosis due to their late presentation, local invasion, and difficulty in achieving complete resection. However, advances in radiation therapy and targeted chemotherapy have improved survival rates in recent years.
• Survival rates depend on the stage at diagnosis and the tumour's response to treatment, with 5-year survival rates being around 20-30% in unresectable cases.