Primary Pulmonary Histiocytosis X

¹ Fellow in Medicine, Mayo Foundation
² Section of Surgery
³ Section of Surgical Pathology
⁴ Section of Medicine

Data have been presented concerning seven patients with primary pulmonary histiocytosis X who have been seen at the Mayo Clinic, and 21 additional patients with this disease whose cases have been reported in the literature.

Primary pulmonary histiocytosis X is a disease of unknown etiology. It occurs more frequently in men than in women and is characterized from the pathologic stand-point by interstitial histiocytic infiltration and destruction of the parenchyma of the lung.

In general, the symptoms, physical signs, and laboratory data for these patients are rather nonspecific and of little diagnostic value. Nevertheless, roentgenograms of the thorax which show evidence of diffuse reticulonodular pulmonary fibrosis, particularly when associated with numerous small cystic areas (the "honeycomb lung") , should at least suggest the possibility of the disease. If, in addition to these x-ray findings, there is evidence of one of the known complications of the disease, such as spontaneous pneumothorax or diabetes insipidus, the possibility of primary pulmonary histiocytosis X should be strongly considered. However, a positive diagnosis can be established only by biopsy of a specimen from the lungs.

The clinical course of primary pulmonary histiocytosis X is both variable and unpredictable. For this reason the prognosis should always be guarded. As a rule, the disease runs a mild and chronic course with a tendency toward remission. However, at times it may progress relentlessly to the point of severe pulmonary fibrosis, cor pulmonale, and congestive cardiac failure.

At the time of this study, cortisone or cortisonelike preparations given early in the course of the disease would seem to be the treatment of choice for primary pulmonary histiocytosis X.

Too few cases of primary pulmonary histiocytosis X have been reported and follow-up study in the cases that have already been reported has not been long enough to provide much knowledge about the natural history of the disease and the value of various forms of treatment, including that with cortisone.