[The histomorphology of granulomatous lipid pneumonia due to dietary fat aspiration in achalasia of the esophagus (megaesophagus)].

In some cases of achalasia, lungs may show characteristic granulomatous pneumonia, following non-symptomatic spill-over and aspiration of fat. The lesion is characterised by fat-containing vacuoles, necrosis, granulocytes, macrophages, some of them with lipid content, epithelioid and giant cells and fibrosis rich in lymphocytes. The histological pattern is pathognomonic and represents an entity. These alterations may be mistaken for tuberculosis and be distinguished from mineral-oil pneumonia (paraffinoma). Affected lung regions may be colonised by nontuberculous (atypical) mycobacteria.