January 2, 1981

Dirofilaria immitis Lung Nodules

Author Affiliations

Malden Hospital Malden, Mass Tufts-New England Medical Center Boston

JAMA. 1981;245(1):30-31. doi:10.1001/jama.1981.03310260014011

To the Editor.—  The BRIEF REPORT (1980;243:1066) on lung nodules caused by the dog heartworm Dirofilaria immitis emphasizes the disproportionately large, globular area of necrosis with a distribution inconsistent with simple embolic infarction. The authors suggest that centrifugal diffusion of worm antigen is instrumental in defining the extent of the zone of coagulative necrosis. A similar phenomenon occurs in pulmonary aspergillomata—especially those that arise from a preexisting Aspergillus pneumonia. In a case to be described in detail in a future publication,1 I have observed the abrupt conversion of diffuse Aspergillus infiltrate to fungus ball. This change occurred within several days and coincided with recovery from prolonged chemotherapy-induced agranulocytosis in a young woman with leukemia. The fungus balls were surgically removed and found to be composed of hyphal elements in a framework of necrotic lung tissue. Similar "ghost-like preservation of alveolar and vascular structures" was described by the authors in