[Nine cases of pulmonary sarcoidosis predominantly affecting the lower lung fields].

OBJECTIVES

Pulmonary sarcoidosis which predominantly affects the lower lung fields is relatively rare. We performed this study to clarify the clinical manifestations of this type of sarcoidosis.

SUBJECTS AND METHODS

Over a period of 13 years, we diagnosed pulmonary sarcoidosis in 119 patients. Among these, we reviewed the clinical characteristics of 9 patients (3 men, 6 women, mean age 62 years) with pulmonary lesions predominantly affecting the lower lung fields.

RESULTS

Four patients had a history of dust inhalation and 6 had symptoms of dyspnea. All patients had ocular lesions and 5 had cutaneous lesions. Serum KL-6 levels were elevated in all patients, whereas angiotensin-converting-enzyme (ACE) levels were elevated in 3. Pulmonary function tests revealed stenosis in 4 patients, and decreased diffusion capacity in 7. Chest CT findings in the lower lung fields revealed bronchovascular thickening, micronodular opacities in the vessels and chest wall, and interlobular septal thickening in 8 patients; ground-glass opacities in 5; curvilinear shadows in 4; and patchy shadows, traction bronchiectasis, and pleural effusion in 3. Histopathologic findings of lung biopsy specimens featured granulomas in all patients, and pulmonary interstitium fibrosis and small round-cell infiltration in the alveoli of most patients.

CONCLUSION

Patients with sarcoidosis affecting the lower lung fields often had symptoms of dyspnea, extrapulmonary lesions in the eye and/or on the skin, and elevated serum KL-6 levels but not ACE. Chest CT showed findings typical of sarcoidosis, such as lymphatic distribution, but also showed unusual findings such as ground-glass opacities, curvilinear shadows, patchy shadows, traction bronchiectasis and pleural effusion. We speculated that 1 patient with ground-glass opacities and traction bronchiectasis without lymphatic distribution on CT, and fibroblastic foci with active alveolitis histopathologically, had complications of a different type of interstitial pneumonia.