Clin Infect Dis 16:51-53, 1993). Here we report the identification of Legionella pneumophila isolates, from subcutaneous abscesses in an immunocompromised patient, that grew in an unusual medium for Legionella bacteria. CASE REPORTA 72-year-old man presented with a 3-week history of painful erythematous lesions of the right foot. His medical history was marked by a rectal adenocarcinoma with lung metastasis managed by chemotherapy and radiotherapy and complicated by radiation-induced pulmonary disease. Three weeks before his admission, he was hospitalized for pneumonitis, which was treated empirically with a combination of piperacillin and tazobactam (Pip/Taz; 4/0.5 g given intravenously for 30 min every 8 h) for 15 days. His fever and respiratory signs resolved but were followed by the occurrence of the skin lesions that led to his hospitalization. On admission, clinical examination revealed no fever and stable hemodynamic parameters. Skin examination revealed two newly appearing erythematous plaques over the internal malleolus and the second and third metatarsophalangeal joints of the right foot, measuring approximately 30 mm in diameter each, in the absence of previous local trauma. Palpation of the lesions revealed fluctuation signs with tenderness. The rest of the clinical examination was normal, with neither pulmonary abnormalities nor cardiac murmur. His white blood cell count was 10,900 leukocytes/mm 3 with 80% neutrophils. His serum C-reactive protein level was increased to 60.3 mg/liter. Other routine laboratory blood tests were normal. A computed tomography (CT) scan of the right lower limb revealed two subcutaneous collections below the erythematous zones without joint effusion (Fig. 1). As fine-needle aspiration of the subcutaneous collections revealed frank pus, surgical drainage of the abscesses was performed before antibiotic therapy based on amoxicillin-clavulanate was started. The pus samples were processed according to standard operating procedures. Gram staining of tissue samples did not show any bacteria, and samples were inoculated into Columbia sheep blood agar (Oxoid), supplemented chocolate agar (bioMérieux), and thioglycolate broth (Oxoid) and incubated for 15 days at 37°C with 5% CO 2 . Additionally, brucella blood agar (BD) was inoculated and incubated for 15 days at 37°C under anaerobic conditions. The Columbia sheep blood agar, thioglycolate broth, and anaerobic cultures did not show growth after 3 weeks of incubation. On day 9, small, catalase-positive, oxidase-positive pinpoint colonies were noted only on the supplemented chocolate agar medium (Fig. 1). No identification was obtained by conventional phenotypic methods. Analysis of the 16S rRNA gene sequence by a previously described method (1) revealed 100% identity with Legionella pneumophila. A Legionella-specific PCR assay (with primers designed to amplify a 106-bp DNA fragment of the 16S rRNA gene specific to Legionella species) secondarily performed was positive, explaining the absence of growth on the other media. In consequ...