Pulmonary malacoplakia associated with rhodococcus equi infection in an AIDS patientcytology of fine needle aspirates of primary extragonadal germ cell tumors

BACKGROUND: Malacoplakia is an uncommon, peculiar inflammatory disease with few cytologic descriptions. It is seen mostly in the lower urinary tract, with rare occurrences in the lungs. Escherichia coli is the most common underlying etiologic agent, with only a few cases reported with Rhodococcus equi infection. CASE: A 36-year-old female with AIDS presented with dysphagia, dry cough and fever. Physical examination revealed diffuse bronchi and wheezing. Chest roentgenography showed multiple cavitary lesions bilaterally in the lungs. Fine needle aspiration (FNA) of one of these lesions revealed clusters of granular histiocytes with numerous intracytoplasmic and extracytoplasmic Michaelis-Gutman bodies. Also noted were numerous coccobacillary bacteria, which, on culture, were identified as R equi. Ultrastructural findings are also presented. CONCLUSION: The case illustrates the cytologic findings of malacoplakia in a rare pulmonary lesion associated with R equi infection in an AIDS patient. It reiterates the diagnostic role of FNA in dealing with a nonneoplastic entity for timely and definitive treatment and follow-up.