Age Morphology of Primary Tubercles

CHAPTER 4: The Pathology of Pulmonary Tuberculosis

“…The structure of this capsule is a reflection of the state of balance between the tubercle bacillus and the host and the length of time that the lesion has remained static. Sweany (1941) has studied this aspect in detail, showing that lesions are initially encapsulated by cells only, later in part by collagen, and finally entirely by collagen. Calcification may occur microscopically after 2 months, but radiological calcification takes about 12 months.…”

Resorption of calcification in primary pulmonary tuberculosis

“…No doubt the monocytic cells described by Sweany (1966) are the mediators of it. As to the actual chemical composition of the deposits, Nordin (1969), also in a personal communication, states that 'the exact composition of these calcific deposits is not known.…”

“…The remarkable clearing of calcification illustrated in the two patients above, and in many others of the series, suggests that some process other than simple expectoration of calcified masses is at work and that calcified lesions can frequently be resorbed. In his description of the age morphology of primary tubercles, Sweany (1941) states that 'calcification shows first at about five months in sections stained with Haemalum and Eosin and around one year in post-mortem x-rays. It increases for about 10 years and then is gradually resorbed or changed to bone.…”

“…There were no symptoms related to these radiological events in any of the children. Sweany (1966), in a personal com-…”