3) Manage Propionibacterium abscess with surgical drainage and antibiotic monotherapy. CASE INFORMATION: A fifty-two year old white male presented with a lump on the head for over a year. Magnetic resonance imaging (MRI) showed a mass lesion in the parietal lobe. He subsequently underwent craniotomy for an epidural neoplasm and left parietal reconstruction with duragen. He then received two doses of radiotherapy. About three months later he presents with right sided weakness, focal seizures in the right hand and a fight facial palsy. After recurrent seizures on anticonvulsant therapy a repeat computed tomography scan and MRI scan was done which showed an epidural lesion with mass effect. The patient was afebrile and had a normal peripheral blood count. The patient was taken to surgery and an epidural abscess was drained. The abscess aspirate on gram stain revealed pleomorphic gram positive bacteria. Aerobic cultures were negative and so were the anaerobic cultures initially but after several days of incubation they grew out a pure culture of a pleomorphic gram positive organism which was identified as Propionibacterium acnes. He was started on intravenous ceftriaxone for 6 weeks and he recovered fully after completion of therapy. DISCUSSION: This case illustrates a case of post-surgical epidural abscess caused by Propionibacterium acnes. Propionibacterium acne is a corynebacterium usually isolated from the human skin where it plays a role in the pathogenesis of acne vulgaris. There have been reports in literature of clinically significant infections related to CNS shunts, intracranial abscesses related to dental sepsis, sepsis related to indwelling vascular catheters, and also a few cases of intracranial abscesses unrelated to foreign bodies. The above case is an addition to these rare cases of intracranial abscesses caused by this unusual pathogen. They are slow growing organisms and as their identification presents problems, they have been frequently overlooked as contaminants. It has been suggested that grain positive rods on gram stain and negative aerobic cultures of suspected infected fluids without organisms on gram stain should be cultured anaerobically. Most infections reported in literature were treated with a combination of antibiotics, though there have been reports of successful treatment with penicillin and surgical drainage alone. The above case also shows how ceftriaxone monotherapy is an effective treatment for such infections along with surgical evacuation of the abscess. year-old male with HIV (CD4 of 343, undetectable viral load) was admitted to the hospital with shortness of breath. He was diagnosed with pneumocystis pneumonia vs cocci pneumonia and treated with Bactrim and Fluconazole. One week later he returned with continuing dyspnea. A VQ scan showed high probability for pulmonary embolism. He was treated with heparin then coumadin and discharged. Three days later he returned with new left lower extremity swelling and pain. He had been taking Coumadin with an INR of 5.1. He denied shortness of breath, chest pain, IV drug use, smoking, ETOH, or recent travel. His medications included Abacavir, Efavirenz, Nelfinavir, Fluconazole, and Bactrim. Physical examination revealed a tender, swollen left lower extremity with a positive Homan's sign. An ultrasound showed thrombosis in the left popliteal vein. The swelling and pain resolved with heparin and he was discharged on Lovenox. A hypercoagulable evaluation revealed normal levels of protein S, activated protein C resistance, anti-thrombin III, and homocysteine. Protein C was slightly elevated. Lupus anticoagulant and anti-cardiolipin antibody were negative. An abdominal CT revealed no mass lesions. DISCUSSION: Thrombosis is an uncommon complication of HIV infection that many primary care providers may not be aware of. Anecdotal evidence in the literature relates thrombosis and HIV, especially in patients with IV drug use, Kaposi's, cytomegalovirus (CMV) disease, megestrol use, protease inhibitor use (including nelfinavir), and hypercoagulable states such as anticardiolipin antibody and protein S deficiency. A recent epidemiologic study showed that HIV patients with thrombotic events had the following characteristics: age greater than 45 years, CMV disease, AIDS-defining opportunistic infection, hospitalization, megestrol use, and indinavir use. The only risk factors for thrombosis that this patient had were hospitalization and nelfinavir use. HIV itself may be a risk factor for thrombotic events and should be considered in cases where shortness of breath remains unresolved despite maximal medical therapy. The mechanism by which HIV causes thrombosis remains unknown but several theories have been proposed. This case illustrates that the link of HIV as a possible cause of thrombosis may have implications for prophylaxis in HIV patients. There are no consensus studies and prophylaxis remains at the discretion of the clinician.