INTRODUCTION: Epstein-Barr virus-associated endobronchial leiomyomas are very rare, benign smooth muscle tumors. They arise from smooth muscle cells in the bronchial wall and have been reported in children with HIV. Here we report a case of an EBV-associated endobronchial leiomyoma discovered in an adult patient with congenital AIDS admitted to the hospital with Pneumocystis pneumonia.
CASE PRESENTATION: A 21-year-old woman presented with shortness of breath, productive cough and fatigue for one month. She had a history of congenital AIDS with a CD4 count of 3. On examination, she had a temperature of 100.9F and bilateral diffuse crackles. Chest CT scan revealed bilateral ground glass opacities in both lung fields without any other abnormalities. Flexible fiberoptic bronchoscopy was performed to further delineate the etiology of her pneumonia. On surveillance, a friable white avascular appearing polyp was seen at the orifice of the lateral-basal segment of the right lower lobe, which was biopsied using alligator forceps. Pathology revealed a nodule composed of spindle cell proliferation without significant nuclear pleomorphism or increased mitotic activity. Immunohistochemical stains for EBV and smooth muscle antigens (HHF and caldesmon) were strongly positive. S100 was focally positive and Ki-67 showed a proliferative index of approximately 5%. These findings were consistent with the diagnosis of EBV-associated leiomyoma. In addition, bronchial washing cultures disclosed Pneumocyctis Jiroveci.
DISCUSSION: Epstein Barr virus-associated endobronchial leiomyomas are benign tumors that arise from smooth muscle cells in the bronchial wall and have been reported primarily in children with congenital HIV. EBV-associated smooth muscle tumors can be found in many other organs including the brain, gastrointestinal tract, liver and adrenal glands. In the lungs, endobronchial tumors are most often discovered incidentally in asymptomatic patients. Tumors may also cause recurrent atelectasis or post-obstructive pneumonia. Radiographically, an endobronchial leiomyoma may be seen on Chest CT scan as an endobronchial opacity but more commonly it is found during bronchoscopy as a white polypoid lesion attached to the bronchus. The differential diagnosis of endobronchial polypoid lesions in HIV patients is tuberculosis, kaposi sarcoma, bronchial carcinoid tumors, benign fibroepithelial polyp, adenoid cystic carcinoma and mucoepidermoid carcinoma. EBV-associated smooth muscle tumors appear to arise when patients exhibit modest immunosuppression due to underlying HIV infection. The pathogenesis of EBV-associated leiomyomas is related to infection with EBV and neoplastic transformation of smooth muscle cells by EBV, with clonal expansion. However, the exact mechanism of tumor genesis is still unclear. EBV seems to play no part in smooth muscle tumors in HIV-negative patients. These tumors do not need to be removed unless clinically causing symptoms. Other treatment options include resection, highly active antiretroviral therapy (HAART) and less often chemotherapy and radiotherapy. The patient was treated with trimethoprim-sulfamethoxazole for Pneumocystis pneumonia and the endobronchial lesion was not treated, as it was clinically asymptomatic. She recovered well and was subsequently discharged from the hospital with resolution of her symptoms.
CONCLUSIONS: Endobronchial EBV-associated leiomyomas in adults are very rare tumors that should be recognized by pulmonary physicians. They should be included in the differential of endobronchial polyps in immunosuppressed patients. They have been reported in the literature mainly in children with congenital HIV; however, they can also be seen in adults.
Reference #1 Dmello, D, Javed, A, Espiritu, J, Matuschak, G: Endobronchial Leiomyoma: Case Report and Literature Review. J of Bronchology & Interventional Pulmonology. 2009; 16:1: 49-51
Reference #2 McClain K, Leach C, Jenson H, Joshi V, Pollock B, Parmley R, Dicarlo F, Chadwick E, Murphy S: Association of Epstein Barr Virus with Leiomyosarcomas in young people with AIDS. New England Journal of Medicine. 1995; 332: 12-18
DISCLOSURE: The following authors have nothing to disclose: Mohammed Sharif, Vicky Seelall
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