HUMAN-IMMUNODEFICIENCY-VIRUS INFECTION AND MULTILOCULAR THYMIC CYSTS

PURPOSE: Pathologic changes of the thymus, often seen in children with the human immunodeficiency virus (HIV), reflect direct invasion by th e virus, followed by involution of the gland. A previously unknown for m of thymic response to HIV infection, that of a multilocular thymic c yst, is reported. MATERIALS AND METHODS: Findings were examined in thr ee HIV-positive patients, two children and one adult first seen with l arge thymic masses. RESULTS: All three had large, septate low-attenuat ion areas at computed tomography consistent with multilocular thymic c ysts. The cystic nature of the lesions was confirmed with magnetic res onance imaging in two. Histopathologic examination, performed in two i nstances, helped establish the diagnosis. All, patients remained in cl inically stable condition. They all had parotid gland enlargement and lymphocytic interstitial pneumonia. CONCLUSION: Multilocular thymic cy sts are probably another manifestation of the diffuse infiltrative lym phocytosis syndrome, usually associated with a milder course of acquir ed immunodeficiency syndrome.