<Case 1> 68-year-old female, who had ten years history of rheumatoid arthritis. She was hospitalized with renal insufficiency. The diagnosis of amyloidosis was made by the gastric biopsy and started hemodialysis. Two months later, pyrexia developed. <Case 2> 70-year-old female, who had four years history of polyarteritis nodosa. She was hospitalized with a recurrence of mononeuritis multiplex. The dosage of prednisolone was increased from 10 mg to 60 mg, and cyclophosphamide was used. Although, neurological signs improved, pyrexia developed. We were not able to identify pleural effusion in CT scans in either of the two cases. Ga scintigraphy showed the strong accumulation in both lung fields, and we diagnosed this as pleurisy. Since the antituberculous drugs was effective, tuberculosis pleurisy was highly suspected. In these cases, the diagnosis of pleuritis was difficult, due to a lack of pleural effusion. Ga scintigraphy was useful for diagnosis.
