Case 35 Answer

Answer: Metastatic Pulmonary Calcification

Yes, all that cloud-like whiteness is calcium. Classic appearance is fluffy cloud like densities which may or may not appear calcified (because it is so fine, the density/appearance can be misleading). There is often a gradient with lung apices more involved than the bases

Causes include: Chronic Renal failure, Hyperparathyroidism, IV Calcium therapy and multiple myeloma

Reference: https://radiopaedia.org/articles/metastatic-pulmonary-calcification