Case presentation
A 77-year-old man with a history of rheumatoid arthritis (RA) for 15
years was admitted to our department due to organizing pneumonia
secondary to RA. His symptoms and radiological findings improved after
initiating corticosteroid therapy (500 mg/day methylprednisolone for
three consecutive days, followed by 1 mg/kg/day prednisolone), which was
gradually tapered in the outpatient department. He had a medical history
of diabetes mellitus. He had smoked 20 cigarettes a day for
approximately 40 years. He had been treated with iguratimod (25 mg/day)
and prednisolone (3 mg/day) for RA. Approximately 1 year after
discharge, he complained of cough and sputum production. A physical
examination revealed no acute distress, with a blood pressure of 135/67
mmHg, heart rate of 87 bpm, body temperature of 37.1°C, and respiratory
rate of 20/min. A neurological examination showed no abnormalities.
Laboratory tests showed elevated C-reactive protein level and renal
dysfunction. The levels of serum β-D glucan, MPO-ANCA, and PR3-ANCA were
normal. Tests for Aspergillus antigens, interferon-gamma release
assays for Mycobacterium tuberculosis, and tests for
anti-Mycobacteria antibody were negative (Table 1). CT showed multiple
cavities in the right lung (Figure 1A). Sputum culture resulted in the
isolation of C. neoformans , and tests for serumCryptococcus antigens were positive (antigen titer: 1:64).
Bronchoscopy was performed, and culture of the bronchial lavage fluid
was found to be positive for C. neoformans. Therefore, the
patient was diagnosed with pulmonary cryptococcosis. Lumbar puncture was
performed, which revealed clear cerebrospinal fluid with a normal cell
count and normal protein and glucose levels. Tests for the cryptococcal
antigen in the cerebrospinal fluid were negative. The patient received
fluconazole orally (400 mg/day), but the treatment was interrupted due
to drug eruption 1 month later. Subsequently, he was treated with oral
administration of itraconazole (200 mg/day). After the initiation of
this treatment, his symptoms and inflammatory responses in laboratory
tests improved. CT showed that the walls of the lesions became thin and
they coalesced with each other (Figure 1B). Six months after the
initiation of treatment, he complained of exertional dyspnea. CT
revealed enlarged multiple cysts, which may have caused his symptoms
(Figure 1C). The cryptococcal antigen titer was 1:4, and no increase in
the antigen titer was observed thereafter; the treatment was completed
in 9 months.
Although no significant increase in the size of cystic lesions was
observed after the end of treatment, exertional dyspnea of the patient
persisted and the risk of pneumothorax was high; therefore, the patient
is being followed up carefully.