Clinical findings and treatment of disseminated ‘Mycobacterium avium subspecies hominissuis’ infection in a domestic cat

KANEGI, Ryoji; YASUGI, Mayo; NABETANI, Tomoyo; TANAKA, Toshiyuki; WADA, Yusuke; HIRAI, Kotaro; SUGIURA, Kikuya; HATOYA, Shingo

In some reports, NTM phagocytosed by macrophages were detected in cytology of granuloma or BAL, with or without acid-fast staining [15, 21, 22] . However, we did not detect MAH in cytology of the swollen lymph node, liver or BAL with Ziehl-Neelsen staining. Previous studies revealed that Mycobacterium species at different stages of infection can sometimes be extremely difficult to find. Thus, it is recommended that Mycobacterium infection is not ruled out even in cases of negative results of cytological preparations, and that histological examination or polymerase chain reaction should nevertheless be performed [22, 23] . In the present study, lung disease was detected without any symptoms or blood test abnormalities in a medical check-up three months earlier; therefore, we considered our case to be at the early stage of MAH infection. In such cases, it has been reported that specific culture for NTM species of granuloma, BAL and blood has proved useful in human medicine [28] . In our case, bronchus and liver FNA specimens were submitted for culture of Mycobacterium species and shown to be positive. This result indicated that culture for specific NTM species, as well as cytology, should be considered in cases with lung diseases or granulomatous inflammation of uncertain cause.