Tuberculosis Study Guide - M.M. Savula 2002

Secondary forms of pulmonary tuberculosis
Pulmonary tuberculoma

A Tuberculoma is a chronic lesion encapsulated by a Connective Tissue capsule, predominantly characterized by caseous necrosis, measuring over 1 cm in size.

Pathogenesis. Tuberculoma is not the initial stage of tuberculosis. It develops from Other forms of the disease, most commonly infiltrative or focal, and less frequently from others. Unlike Caseous Pneumonia, which is characterized by a tendency toward rapid spread of caseous necrosis and aggressive progression, The formation of tuberculomas is associated with a certain level of host resistance and the body's ability to rapidly wall off caseous masses from healthy tissue.

If peripheral inflammatory infiltration resolves in a patient with infiltrative tuberculosis, and the centrally located caseous core becomes encapsulated by connective tissue, a so-called homogeneous round tuberculoma is formed. If, in focal tuberculosis, a cluster of foci undergoes necrosis and becomes surrounded by connective tissue, an irregularly shaped conglomerate tuberculoma develops. Tuberculomas can be solitary or, less frequently, multiple, ranging from 1.5 to 8 cm in diameter.

Clinical presentation and Diagnosis. Taking the patient's history often reveals a previous illness and Treatment for other forms of Pulmonary Tuberculosis, or contact with an infectious tuberculosis patient. Because the process is encapsulated, clinical symptoms are often absent, and abnormalities are detected during routine screening chest photofluorography. Occasionally, patients may complain of malaise, intermittent low-grade fever, decreased appetite, chest pain, a dry cough or one with minimal sputum production, and, rarely, hemoptysis.

Percussion and Auscultation findings are normal, and mycobacteria are very rarely detected in the sputum. The Mantoux test is positive, sometimes strongly positive.

A chest X-ray reveals a round or oval, well-defined opacity, most commonly in the upper lung fields. Sometimes, small focal opacities—sequelae of past tuberculosis—are found around the tuberculoma or in other areas of the Lungs. If the tuberculoma undergoes cavitation, a crescent-shaped lucency is often visible, typically located eccentrically within the opacity.

Due to similarities in clinical presentation and radiological features, a tuberculoma can resemble Lung Cancer or a fluid-filled cyst; therefore, CT scanning, bronchoscopy, and occasionally a needle biopsy are essential for Differential diagnosis.

The course of a tuberculoma is indolent and chronic. Antituberculosis drugs penetrate its capsule poorly, meaning that conservative treatment is not always effective. Surgical intervention is indicated for large tuberculomas (over 3 cm), in the presence of a cavity with bacterial shedding, or in cases of an uncertain diagnosis.