Characteristics

• Solitary or multiple calcified nodules within the lung. They are often small, widespread and punctate. Solitary granulomata, particularly post TB infection, can be large up to several centimetres in diameter.

• They represent a chronic healed immune reaction, within the lung, to the initial stimulus.

• Post infective causes – TB, post varicella pneumonia.

• Non-infectious causes – inhalation of organic and inorganic chemicals.

Clinical features

• Patients often asymptomatic.

• Previous history of infection or exposure to inhalational chemical.

• Can develop a non-productive cough and shortness of breath.

• Small risk of a pneumothorax.

Radiological features

• CXR – dense calcified sharply marginated pulmonary nodules. They can be solitary, multiple, localised or widespread. Distribution may correlate with the underlying cause, e.g. previous TB in the upper lobes.

• There is no growth in size of the calcified nodules over time.

Differential diagnosis

• Calcified lung metastases (e.g. breast, thyroid, osteosarcoma, ovarian, testicular and mucinous tumours). They can be multiple or solitary. They are often larger in size with an antecedent history supporting the primary neoplasm. Importantly they enlarge over time.

• ALWAYS COMPARE WITH OLD FILMS.

• If concerned repeat the CXR at an interval period in time.

Management

• No active management required.

• No surveillance necessary.