関節リウマチの若年女性における気管支内マクロラキア：症例報告

Malakoplakia is a rare inflammatory condition characterized by the accumulation of granulomatous masses due to the incomplete destruction of infectious pathogens by monocytes and macrophages. While it commonly affects the genitourinary tract, pulmonary malakoplakia is infrequent and often associated with immunocompromised states. We present the case of a woman in her early 40s with rheumatoid arthritis who developed localized pulmonary malakoplakia in the airway. Initially presenting with constitutional symptoms and respiratory distress, she underwent a diagnostic evaluation revealing an endobronchial mass with neoplastic characteristics. Histopathological examination confirmed the presence of Michaelis-Gutmann bodies, pathognomonic for malakoplakia. Despite initial improvement postresection, the patient experienced disease recurrence 1 year later. Pulmonary malakoplakia, although rare, poses diagnostic challenges due to its resemblance to malignant lesions. Treatment typically involves antibiotic therapy, low-dose steroids, and localized resections. Differential diagnoses include primary or secondary malignancies, necessitating histopathological evaluation for accurate diagnosis. Malakoplakia should be considered in immunocompromised individuals presenting with pulmonary nodules or masses, especially without malignancy risk factors.