Enlarging pulmonary histoplasmoma.

Abstract

The finding of solitary pulmonary nodules (coin lesions) in nonsymptomatic persons has been one of the more provocative results of chest roentgenography of large numbers of adults. Resection is often performed because of inability to make an absolute diagnosis by clinical, roentgenographic, or laboratory means. The accumulated pathologic material, especially from patients less than 45 years old, has resulted in a lower incidence of cancer ( less than 50 per cent) and a higher incidence of granuloma than might be suspected (1-10). The work of Puckett (11), using the periodic acid-Schiff stain, revealed histoplasmosis as one of the causes of granulomatous solitary pulmonary nodules. Confirmation of this work (12) and e\'aluation of large series of resected lesions reyealed that histoplasmosis may well be the commonest cause of these granulomatous solitary nodules (2, 13) in many areas of the United States. These lesions are usually morphologically inactive, and eulture of the lesions is almost always sterile. Therefore, if the diagnosis could be made with certainty clinically or by roentgenography, pulmonary resection would be unnecessary. For this reason efforts at establishing diagnostic criteria have been made but, with the exception of the demonstration of laminated calcification within the lesions roentgenographically (posteroanterior, lateral, and/or laminagram), no reliable signs have resulted (13, 14). Previous chest films when available are often extremely helpful as it is generally agreed that the appearance of a llei\' noncaleified lesion is suggestive of malignancy (15, 16), and the enlargement of a lesion seen previously indicates malignancy or acti ve infection (2, 4, 5, 7). The present writers have observed 4 cases of solitary histoplasmoma of the lung, all treated by resection, which had manifested roentgenographic growth over a period of years (table 1, figures 1-4). All of the present cases were inactive granulomas.