The Tuberculous Round Focus in Its Chronic Form

¹ The Chest Department and the X-Ray Department of the Sick Fund Clinic of the Israel Federation of Labour, Haifa, Israel.

In the course of mass-radiographic examinations of new immigrants, carried out in reception camps in Israel, 104 cases were recorded within a short period, showing the radiological finding of a "round-shadow" within the lung. In the early stages of the examinations the lesions were considered of fibrotic (scarring) character.

Clinical, radiological and bacteriological investigations, particularly cultures grown from gastric washings, however, revealed that we were dealing with chronic round foci, which in the majority of cases turned out to be the manifestation of an active tuberculous process of latent character.

A clinical definition of the "tuberculous round focus in its chronic form" has been given and the differential characteristics from the tuberculous round lesion in its acute or subacute form ("early infiltration," Assmann) have been shown, the relationship to the "inspissated cavity" has been discussed.

The pathology of the chronic round foci is assumed to be a lesion surrounded by a capsule of connective tissue containing material of differing histological architecture, in the majority of cases the enclosed materials being predominantly caseous. The pathogenesis of the lesion is considered to be that of a bronchogenous reinfection.

The treatment is chiefly conservative. If active treatment becomes necessary, resection is preferable to collapse.

The term "round-shadow" is a definition of a radiological appearance which is common to many differing pulmonary diseases. The differential diagnosis of these may be complicated.