CASE 11: A PERSISTENT COUGH IN AN EX SMOKER

History

You are asked to review a 67-year-old man in the chest clinic. He has been sent by his general practitioner (GP) who has been treating him for a cough. His symptoms started 3 weeks ago, at about the same time that the patient decided to stop smoking. The cough is chesty but non-productive, and is there constantly, but not worse, at night. He has no other new symptoms and is no more short of breath than usual, with an exercise toler- ance of approximately 200 m. His appetite is unchanged and he has not lost weight. He does report occasional streaks of fresh red blood in the sputum on deep coughing. The patient has a past medical history of excessive alcohol intake and chronic obstruc- tive pulmonary disease (COPD). He had two previous admissions to hospital with decom- pensated liver disease, but has now abstained from alcohol for over a year. His last ultrasound scan confirms a degree of liver cirrhosis. He has smoked with a 60 pack-year history. He has never been admitted to intensive care with exacerbations of COPD, but has been treated for pneumonia in the past. He recently decided to stop smoking as his new girlfriend does not like to ‘kiss an ashtray’.

Examination

As part of his management, the GP performed a chest radiograph (Figure 11.1) and then referred him to the chest clinic.

Figure 11.1 Chest radiograph.

Questions

• What does this chest radiograph demonstrate?

• What further radiological investigations are required?

ANSWER 11

This is a diagnostically adequate posterior–anterior (PA) chest radiograph of an adult male patient. There is a 2.3 cm rounded mass lesion within the left mid zone adjacent to the left hilum that appears to cavitate in its inferior aspect. No other pulmonary parenchymal nod- ularity is seen. There is blunting of the costophrenic angles bilaterally which may represent either small pleural effusions or be longstanding related to pleural thickening. There is a background of emphysematous change as evidenced by lung hyperinflation and flattening of the hemidiaphragms. Bilateral gynaecomastia is also noted. The rounded lesion may rep- resent a malignancy in the form of a lung primary in view of the clinical history, however a focus of infection or metastasis cannot be excluded. Correlation with old films is advised. The suspicious nature of this pulmonary mass lesion warrants a computed tomography (CT) scan, which ideally should be performed with intravenous contrast. Although the chest X-ray only demonstrates a solitary lesion, a CT scan of the chest and abdomen is recommended. This allows characterization of both the lungs and mediastinum, and also assesses the solid abdominal viscera (e.g. liver and adrenals), which are sites of common involvement in disseminated lung cancer. Extending the CT to involve the abdomen allows for accurate staging of primary lung cancer, and the patient can be referred to the lung multidisciplinary meeting (MDM) for further discussion.

The CT scan confirms a background of centrilobular emphysema and a left lower lobe pulmonary nodule measuring 2.6 × 1.6 cm (Figure 11.2). This tethers the oblique fissure and demonstrates an adjacent airspace opacification with cavitation. No disease was seen in the contralateral lung, mediastinum or below the diaphragm. Findings are compatible with a primary bronchial malignancy.

The patient was then referred to the MDM. Time is an important factor to limit the spread of disease, and efficient transfer of patient care through the relevant specialities is of utmost importance to expedite definitive treatment.

A tissue diagnosis is important to obtain histological characterization of the lesion. Although cavitation and a history of smoking infers a likely squamous cell aetiology, histological confirmation is essential to tailor further chemotherapy or surgical treatment. The location of this lung primary would necessitate a CT-guided biopsy under the aus- pices of the interventional radiologists. A coaxial needle system is passed under CT guid- ance and local anaesthetic cover into the lesion, and a core biopsy sample taken (Figure 11.3). Patients should be consented for the risk of lung contusion and pneumothorax.

Figure 11.3 Biopsy under CT guidance.

A positron emission tomography (PET) scan is indicated in potentially operable tumours to assess nodal status and occult metastatic disease. This is required for complete disease staging and will dictate further treatment. If the PET scan confirms that this lesion is soli- tary and there is no evidence of nodal or metastatic spread, then the patient may be eligible for definitive surgery in the form of lobectomy if medically fit, although careful assess- ment will be needed in view of his significant COPD. Should the PET scan suggest inoper- able or disseminated disease, then a chemotherapeutic treatment may be more appropriate. A PET scan is a nuclear medicine scan, usually performed in combination with a CT scan. PET uses a radioactive isotope with a short half-life (e.g. fluorine-18 (F18_{)), which is bio-}

chemically incorporated into the functionally active glucose molecule fluorodeoxyglucose (FDG). It is used extensively in oncology imaging because the FDG–F18 _{is concentrated}

in metabolically active tissues, radiolabelling those tissues with high amounts of glucose uptake. Although there is physiological uptake in organs such as the brain, heart and liver, primary cancers and their metastases can also be detected by the PET scanner, as the F18 _{undergoes positron emission decay. The images obtained are fused with unenhanced,}

Although not its primary function, CT can also allow further detection and assessment of both related and unrelated pathology. As well as primary staging, PET scanning can be used to assess response to treatment. Despite being an effective tool, its major limitations are related to cost (both of the scanner and in generating the isotope) and lesion size: small metastases (<1 cm) may not accumulate detectable levels of FDG–F18_.

KEY POINTS

• A patient with a chest radiograph suspicious for lung cancer should be referred for a chest CT scan to characterize the lesion further.

• Lung biopsy can be performed under CT guidance for histological characterization. • A PET scan is often used to assess suitability when planning the treatment for a patient

CASE 12: