# Pancoast Syndrome

> Pancoast syndrome for NEET-PG Medicine covers apical lung tumours, Horner syndrome, C8-T1 pain, MRI staging and multimodality treatment with chemoradiotherapy.

- Canonical URL: https://prepelephant.com/topics/neet-pg/medicine/pancoast-syndrome
- Exam / course: NEET-PG · Subject: Medicine
- Publisher: PrepElephant (https://prepelephant.com) — Prepared and reviewed by the PrepElephant Academic Review Team
- First published: 2026-10-14
- Last updated: 2026-10-14
- Reference basis: Harrison's Principles of Internal Medicine; Bailey and Love's Short Practice of Surgery
- How to cite: "Pancoast Syndrome", PrepElephant, https://prepelephant.com/topics/neet-pg/medicine/pancoast-syndrome

## Direct answer

Pancoast syndrome is a combination of shoulder and arm pain, Horner syndrome and hand muscle wasting caused by an apical lung tumour invading the thoracic inlet. The tumour is usually a non-small-cell carcinoma, historically squamous, and it compresses the lower trunk of the brachial plexus (C8 and T1) and the sympathetic chain. Diagnosis rests on CT, MRI and biopsy, and treatment is usually chemoradiotherapy followed by surgery in selected patients.

## What you must remember

- **Location:** the tumour sits in the apex of the lung, the superior sulcus, where it reaches structures at the thoracic inlet.
- **Horner syndrome:** ptosis, miosis and anhidrosis from involvement of the cervical sympathetic chain and stellate ganglion.
- **Nerve involvement:** pain radiating along the medial forearm, with ulnar-sided hand wasting, from C8 and T1 lower trunk injury.
- **Bone involvement:** first and second ribs and the adjacent vertebrae are commonly eroded in the classic presentation.
- **Imaging:** CT shows the chest and bones, MRI defines brachial plexus and spinal involvement, and PET-CT helps with staging.
- **Histology:** usually non-small-cell carcinoma, and EGFR, ALK and PD-L1 testing guides systemic therapy.
- **Staging:** chest wall, vertebral and vascular invasion decide the stage, and most Pancoast tumours are stage IIB to IIIA.

## A stepwise evaluation of an apical mass

A 58-year-old smoker has right shoulder pain that radiates to the medial forearm, along with ptosis and a small right pupil. A chest radiograph shows an apical opacity with erosion of the first rib, which points to a tumour at the thoracic inlet.

1. **Recognise the triad:** shoulder and arm pain, Horner syndrome and hand wasting together point to an apical tumour rather than a musculoskeletal cause.
2. **Image the apex:** CT of the chest and MRI of the brachial plexus and spine define the extent into the chest wall, vertebrae and subclavian vessels.
3. **Biopsy and profile:** CT-guided or bronchoscopic biopsy provides histology, and molecular testing guides therapy.
4. **Stage fully:** PET-CT and brain imaging exclude distant metastases and confirm whether the disease is locally advanced.
5. **Give concurrent chemoradiotherapy:** induction chemoradiotherapy with reassessment is the standard approach for locally advanced disease.
6. **Consider surgery:** en bloc resection, often by a posterior approach, is offered to fit patients who respond to chemoradiotherapy.

## Where the exam tries to catch you

Pancoast syndrome is missed when its pain is treated as a shoulder problem.

- **Trap:** treating shoulder pain with physiotherapy in a smoker with Horner syndrome — **Correct:** Horner syndrome with arm pain signals an apical tumour until proved otherwise.
- **Trap:** relying on a standard chest radiograph to exclude an apical tumour — **Correct:** apical tumours hide behind the clavicle and first rib, so CT and MRI are needed.
- **Trap:** choosing surgery first for every patient — **Correct:** locally advanced Pancoast tumours are usually treated with chemoradiotherapy before surgery.
- **Trap:** confusing Pancoast syndrome with carotid dissection, which also causes Horner syndrome — **Correct:** Pancoast adds shoulder-arm pain and hand wasting, while carotid dissection causes headache and neck pain.

## Frequently asked questions

### Which nerve roots are affected in Pancoast syndrome?

The lower trunk of the brachial plexus, formed by the C8 and T1 nerve roots, is affected in Pancoast syndrome. This explains the medial forearm pain and the ulnar-sided wasting of the small hand muscles.

### What are the features of Horner syndrome?

Horner syndrome consists of ptosis, miosis and anhidrosis, often with apparent enophthalmos. It results from interruption of the sympathetic pathway to the eye and face, which is why it accompanies an apical lung tumour.

### Which imaging is best for an apical lung tumour suspected to be Pancoast?

CT of the chest defines the tumour and its effect on the chest wall and bones, while MRI best shows brachial plexus and spinal involvement. PET-CT is then used for staging before treatment is planned.

### Which treatment sequence is standard for locally advanced Pancoast tumour?

Concurrent chemoradiotherapy is given first, followed by surgical resection in selected patients who respond. This sequence is preferred because it controls the tumour before the surgical field is operated on.

### Which histology is most common in Pancoast tumours?

Non-small-cell lung carcinoma is the usual histology in Pancoast tumours, with squamous cell carcinoma historically the most common subtype. Small cell carcinoma is rarely the presenting type of an apical tumour.