INTRODUCTION:Mycobacterium genavense is rare among the Mycobacterium species. We report a first case of pulmonary infection with Mycobacterium genavense in a HIV patient with pulmonary Kaposi's sarcoma and cytomegalovirus infection.
CASE PRESENTATION: A 33-year-old male presented with chronic cough, dyspnea, severe weakness, and diarrhea of three month's duration. He had watery diarrhea 3-4 times a day, and the cough was non-productive with periodic mild hemoptysis. He also had 60 lbs weight loss in the last 6 months. He had been diagnosed with HIV/AIDS with Kaposi's sarcoma 5 years back, for which he opted not to be treated. He denied smoking cigarettes, using alcohol, and illicit drugs. He was homosexual. On physical exam, he was cachectic with coarse crackles in bilateral bases. He had diffuse non-tender lymphadenopathy involving cervical, axillary and inguinal regions. There was no oral thrush. Laboratory data showed WBC count of 2000 mm3 with 81% neutrophils, hemoglobin was 6.6 gm/dl, CD4 count was 20 mm3, and HIV viral load was 750,000 copies/mil. The herpes virus PCR, histoplasma, toxoplasma antibody were negative. Blood and stool cultures were negative. CT scan of the chest showed multiple bilateral pulmonary nodules throughout the lung field. There was a spiculated lesion in the right upper lobe, and diffuse ground glass opacities in bilateral lungs. Bronchoscopy revealed pink raised endobronchial lesions in the trachea and the right main stem bronchus showing pulmonary Kaposi's sarcoma. Lung tissue showed noncaseating granuloma with numerous AFB, and many pneumocytes with CMV inclusions. Bronchoalveolar fluid and lung tissue culture for AFB showed growth of Mycobacterium genavense species.
DISCUSSIONS:Mycobacterium genavense was first described by Bottger and colleagues in 18 patients with advanced HIV infection in 1992. They detected an unidentified mycobacterium in blood, lymphnodes, bone marrow, spleen, liver and intestinal biopsies, and named it Mycobacterium genavense. These slow growing mycobacterium consist of small, clumped pleomorphic coccobacilli that range in length from 1-6 μm. They grow in broth media with tiny, transparent colonies. Clinical presentations are similar to disseminated MAC infection. Mycobacterium genavense infection is associated with massive lymphadenopathy and splenomegaly with splenic abscess, and patients more frequently present with abdominal pain. They are responsible for more than 10% of disseminated nontuberculous mycobacterial infection. The strain is susceptible to rifampin and streptomycin and resistant to isoniazide and ethambutol. Pulmonary infection with isolation of Mycobacterium genavense from lung tissue and BAL fluid has not been described in literature. On the other hand Kaposi's sarcoma (KS) is the most common malignancy associated with HIV. It occurs in approximately 6-20 % of HIV infected patients, and more common in homosexual men. In 1994, Chang and colleagues identified DNA fragments of previously unrecognized herpesvirus-Kaposi's sarcoma associated Herpes Virus (KSHV), in KS lesion from patient with AIDS. In patients with KS about 33% will have clinically evident pulmonary disease, and 50% will have pulmonary involvement at autopsy. Pleural effusion are found in two thirds of the patients and intrathoracic lymphadenopathy in up to 46% of the cases. Median survival of extensive pulmonary KS is 6-10 months.
CONCLUSION: This is a rare case of pulmonary involvement of Mycobacterium genavense with its isolation from lung tissue and BAL fluid in a patient with advanced HIV. Coinfection with KSHV and CMV may be the contributing factors for disseminated Mycobacterium genavense infection involving the lung.
DISCLOSURE: Yogesh Shrestha, None.