What is the likely cause and recommended work‑up and management for a patient with sharp pleuritic chest pain below the left nipple radiating to the back, normal electrocardiogram, and unchanged calcified infrahilar nodes on chest radiograph?

Clinical Assessment: Pleuritic Chest Pain with Normal Cardiac Workup

This patient most likely has costochondritis or another musculoskeletal cause of chest pain, given the pleuritic nature (worse with deep breathing), localized distribution below the left nipple with back radiation, and normal ECG with unchanged calcified nodes. 1, 2

Immediate Exclusion of Life-Threatening Causes

Your initial workup appropriately ruled out the most critical diagnoses:

• Acute coronary syndrome is effectively excluded by the normal ECG and the pleuritic quality of pain. Sharp, stabbing chest pain that worsens with deep breathing is atypical for ACS and directs attention away from cardiac ischemia. 1

• However, you must still measure cardiac troponin to definitively exclude myocardial injury, as 5% of patients with normal ECGs can still have ACS. 1 The European Society of Cardiology emphasizes that troponins are the preferred markers and more sensitive than traditional enzymes. 1

• Pulmonary embolism must be considered given the pleuritic nature, as PE is found in 5-21% of patients presenting with pleuritic chest pain to emergency departments. 3 Check vital signs for tachycardia (present in >90% of PE patients), tachypnea, and hypoxia. 4, 3

• Pneumothorax should be excluded through careful auscultation for unilateral decreased breath sounds, though your chest X-ray likely already ruled this out. 4

Most Likely Diagnosis: Musculoskeletal Pain

The clinical presentation strongly suggests costochondritis:

• Pain reproducible by palpation of the chest wall is the key diagnostic feature. Examine the costochondral joints and chest wall for tenderness—pain that can be reproduced with palpation has a likelihood ratio of 0.2-0.3 for cardiac causes. 2, 5

• Pleuritic quality (worse with deep breathing) is characteristic of musculoskeletal pain rather than cardiac ischemia. 1, 2

• Localized pain below the nipple with back radiation in the same distribution suggests chest wall involvement rather than visceral cardiac pain. 2, 6

• Costochondritis accounts for 43% of chest pain in general practice when cardiac causes are excluded. 2

Alternative Diagnoses to Consider

Pericarditis should be on your differential, though less likely:

• Classic features include sharp, pleuritic pain that worsens when lying supine and improves when leaning forward. 2, 4
• Look for a pericardial friction rub on examination. 1, 2
• The ECG may show diffuse ST elevation or PR depression (which you did not describe). 1

Gastroesophageal reflux disease is another common cause:

• GERD can present with chest pain that may have atypical features. 2, 7
• Consider a therapeutic trial of high-dose proton pump inhibitors if musculoskeletal causes are ruled out. 8

Recommended Workup

Complete the following immediately:

• Measure cardiac troponin (preferably high-sensitivity) to definitively exclude myocardial injury. 1
• Perform detailed chest wall palpation examining all costochondral junctions for reproducible tenderness. 2, 6
• Assess vital signs including oxygen saturation, heart rate, and respiratory rate to exclude PE. 4

If troponin is negative and chest wall tenderness is present:

• No further cardiac testing is needed. 6, 9
• The calcified infrahilar nodes are unchanged and likely represent old granulomatous disease (prior histoplasmosis or tuberculosis exposure), which is not contributing to current symptoms. 1

Management Approach

For confirmed costochondritis:

• NSAIDs are first-line therapy: Ibuprofen 600-800mg three times daily for 1-2 weeks. 4, 3
• Reassure the patient about the benign nature of the condition. 2, 9
• Symptoms typically resolve within weeks but may recur. 9

If symptoms persist despite treatment:

• Consider alternative diagnoses including GERD with a trial of proton pump inhibitors. 8, 7
• Re-evaluate for other causes if pain characteristics change or new symptoms develop. 9

Critical Pitfalls to Avoid

• Do not use nitroglycerin response as a diagnostic test—esophageal spasm and other noncardiac conditions also respond to nitroglycerin. 2, 8

• Do not dismiss the need for troponin measurement even with a normal ECG and atypical features, as approximately 5% of ACS patients have normal initial ECGs. 1

• Do not assume pleuritic pain excludes ACS entirely—the Multicenter Chest Pain Study found acute myocardial ischemia in 13% of patients with chest pain having pleuritic features. 1

• Document your physical examination findings carefully, particularly whether chest wall palpation reproduces the pain, as this substantially alters probability of cardiac disease. 5