Pulmonary sarcoidosis in a child with cystic fibrosis

The co-occurrence of cystic fibrosis (CF) and sarcoidosis is rare. This case report describes a patient with both diseases. A 13-year-old girl with known CF (homozygous delta F508 defect) presented with a sudden decline in lung function. FEV1 decreased from 80% to 64% predicted, and FVC from 90% to 80% predicted. Diffusion capacity for carbon monoxide (D(L)CO) was 92% predicted. There was no history of cough, dyspnea, or reduced exercise tolerance, but she had arthralgia of the knee- and ankle-joints. A chest radiograph and CT scan of the thorax demonstrated pronounced bilateral hilar and mediastinal lymphadenopathy, compatible with pulmonary sarcoidosis. Histological examination of lymph node biopsy specimens obtained at mediastinoscopy demonstrated noncaseating epithelioid-cell granuloma. The majority of lymphocytes were CD4+ T lymphocytes, with a CD4+/CD8+ ratio of 5:1. The patient showed a prompt response to treatment with oral corticosteroids, and lung function returned to baseline levels. Subsequent radiographic appearances showed almost complete regression of mediastinal lymphadenopathy. The probability that CF and sarcoidosis would coexist by chance in a Danish child of this age is approximately 1:10(9). The collective incidence and geographic distribution of previously described patients with coexistent CF and sarcoidosis lend support to an association between the two diseases.