Presentation
Routine chest radiography in a study for lumbar pain. History of sand-working exposition for five years.
Patient Data
Multiple bilateral pulmonary calcified micronodules, predominantly in the upper and posterior zones. Note the tendency toward coalescence of the nodules in both pulmonary superior lobes.
CT confirms the presence of innumerable bilateral pulmonary calcified nodules, predominantly in the upper and posterior zones. These nodules have a centrilobular and subpleural distribution. Two partially calcified mass-like conglomerates in both upper lobes with associated radiating strands can be observed (progressive massive fibrosis).
There are also mediastinal and hilar "egg-shell" calcified lymph nodes.
Case Discussion
In this case, the principal differential diagnosis would be between coal worker's pneumoconiosis and silicosis. These two entities have similar radiological appearances, although they have different histological findings. However, the presence of a subpleural distribution of some nodules, the "egg-shell" lymph node calcification and the exposure to sand-working are highly suggestive of silicosis.