Diabetes insipidus may occur. Hyperparathyroidism appears to be unusually frequent and should be considered when hypercalcemia does not promptly respond to corticosteroids. Mediastinal adenopathy often is discovered on routine chest x-ray. Cough and dyspnea may be minimal or absent. Pulmonary fibrosis, cystic changes, and cor pulmonale are late results of progressive disease.
Leukopenia is frequently present, and serum uric acid elevation is common, but gout is rare.
Serum alkaline phosphatase and -glutamyl transpeptidase levels may be elevated as a result of liver involvement. Hypergammaglobulinemia is common in blacks. Pulmonary function tests show restriction, decreased compliance, and impaired diffusing capacity. CO 2 retention is uncommon, although airway obstruction is common in patients with endobronchial disease or in late stages with pulmonary fibrosis or bullae. Serial pulmonary function tests are important for assessing disease progression and guiding treatment.