Practice Rational Imaging

Investigating the solitary pulmonary nodule

BMJ 2012; 344 doi: http://dx.doi.org/10.1136/bmj.e2759 (Published 19 April 2012) Cite this as: BMJ 2012;344:e2759
  1. William McNulty, specialist registrar1,
  2. Giles Cox, consultant respiratory physician1,
  3. Iain Au-Yong, consultant radiologist2
  1. 1Department of Respiratory Medicine, King’s Mill Hospital, Sutton-in-Ashfield NG17 4JL
  2. 2Department of Radiology, King’s Mill Hospital, Sutton-in-Ashfield NG17 4JL
  1. Correspondence to: I Au-Yong iauyong{at}doctors.org.uk
  • Accepted 20 March 2012

The presence of a solitary pulmonary nodule raises the suspicion of cancer and requires careful further investigation to determine whether it is malignant or benign

Learning points

  • Certain chest radiograph appearances, including a solitary pulmonary nodule, raise suspicion of cancer and require prompt referral for further investigation

  • Both radiological and clinical factors influence the probability of malignancy in a solitary pulmonary nodule

  • Computed tomography will help to make the diagnosis, stage the disease, and guide which investigation should be performed to obtain a histological diagnosis

  • Positron emission tomography has high sensitivity for detecting malignant disease and, if available, should be offered to all patients suitable for radical therapy to ensure accurate staging

  • Small nodules have a lower risk of malignancy and may be observed for change over an interval period

An 81 year old man presented to the emergency department with a one week history of fever, cough, and right sided chest pain. He had had a myocardial infarction in 2004 but was otherwise well. He had a 50 pack-year smoking history. Clinical examination was unremarkable. His chest x ray showed a left mid-zone nodule (fig 1). He was treated for a lower respiratory tract infection and referred to the lung cancer clinic with two week wait for an appointment.

Fig 1 Patient’s chest x ray showing a left mid-zone nodule (arrow)

Chest x ray

The chest x ray is often the first investigation where a solitary pulmonary nodule is detected. A solitary pulmonary nodule is a rounded opacity, well or poorly defined, measuring up to 3 cm in diameter.1 They may represent early lung cancer, and prompt detection and treatment may improve clinical outcome. However, some nodules are benign, and determining which require further investigation may be difficult. Some common differential diagnoses are listed in box 1.2 3

Box 1 Common causes of a solitary pulmonary nodule23

Malignant
  • Bronchogenic carcinoma

  • Single …

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