Natural course of pulmonary hyalinizing granuloma over a decade

BACKGROUND: Pulmonary hyalinizing granuloma (PHG) is a very rare pulmonary disease characterized by multiple fibrosclerotic inflammatory lung nodules. The disease is supposedly caused by an unusual immune response. CASE PRESENTATION: We present a case involving a 53-year-old female with a history of lumpectomy surgery due to invasive ductal carcinoma who was admitted for slowly progressive pulmonary nodules. The patient's elevated serum IgG4 level and the pathological findings obtained in surgical biopsy indicated IgG4-related lung disease. The nodules continued to enlarge despite administration of corticosteroid therapy, and we performed a second surgical biopsy to obtain a correct diagnosis. The pathological findings obtained in the second biopsy were different and consistent with the features of PHG. CONCLUSIONS: In this report, the radiological follow-up data obtained after lumpectomy surgery demonstrate the very early stage of PHG and the following radiological changes over a decade, and the two surgical biopsies support us to realize the pathological change from previous diagnosed disease before PHG.