INT 薛乃維 Supervisor: 鄭莉莉醫師 CT Findings of Granulomatous Pneumonitis secondary to Mycobacterium avium- intracellular inhalation AJR:188, April 2007 Department of radiology, mayo clinic scottsdale AZ INT 薛乃維 Supervisor: 鄭莉莉醫師

Objective CT feature of “ Hot Tub Lung” Mycobacterium avium cpmplex (MAC) contaminated water

Background Atypical Mycobacterium cause a wide spectrum disease Immunocompromised pateint MAC is the most common

Background Classic MAC : olderly ♂, COPD or pulmonary fibrosis, indistinguish from reaction TB Non classic MAC: elderly ♀, brochiectasis, nodule, or nodular infiltraion AIDS Focus on CT findings of pathologically proven MAC-induced “hot tub lung”

Material and Method Chart review for a. Pathologically proven granumatous pneumonitis b. Positive culture for MAC From 1995/1/1~2004/1/7 12 patients 5 ♂ 7 ♀ CT image are reviewed by 2 chest radiologist

Material and Method Pulmonary function test for the patient No immunocompromised disease

Material and Method CT done < 1 month of biopsy

Material and Method Parameter: nodule, reticular plague, ground glass, consolidation, honey combing, cyst. Cephalocaudal and transaxial plane

Result 5 ground-glass, 5 solid

Result Air trapping in all 7 cases

Inspiratory CT showed bilateral Ground glass attenuation Expiratory image showed Air trapping

Discussion Characteristic findings of MAC induced granulomatous pneumonitis Non specific, overlapping with sub-acute hypersensitivity pneumonitis sub-acute hypersensitivity pneumonitis is primary diagnosis Air trapping is explained by centrilobular granulomas aggravation

Discussion Centrilobular nodule and random ground-glass, the most common findings Diffuse cephalocaudal through out bilateral lung 7 cases have air trapping

Discussion Whether this disease should be treated as granulomatous disease or hypersensitivity is debate Clinical course is resemble hypersensitivity Remove patient form contaminated water, without treatment of anti-tuberculosis medication Some case treated with anti-tuberculosis medication or steroid

Conclusion Regardless of granulomatous or hypersensitivity, be aware of MAC pulmonary Disease Ground glass attenuation, Centrilobular nodule, air trapping: radiologist should consider MAC-induced pneumonitis

Thanks For your attention