Page 172 - Textbook of Pathology, 6th Edition

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SECTION I

Figure 6.26 Fibrocaseous tuberculosis. A, Non-cavitary (chronic) fibrocaseous tuberculosis (left) and cavitary/open fibrocaseous tuberculosis
(right). B, Chronic fibrocaseous tuberculosis lung. Sectioned surface shows a cavity in the apex of the lung (arrow). There is consolidation of lung
parenchyma surrounding the cavity.

c) Tuberculous empyema from deposition of caseous into pulmonary artery restricting the development of miliary
material on the pleural surface. lesions within the lung (Fig. 6.29). The miliary lesions are
d) Thickened pleura from adhesions of parietal pleura. millet seed-sized (1 mm diameter), yellowish, firm areas
II. TUBERCULOUS CASEOUS PNEUMONIA. The without grossly visible caseation necrosis.
caseous material from a case of secondary tuberculosis in an Microscopically, the lesions show the structure of tuber-
individual with high degree of hypersensitivity may spread cles with minute areas of caseation necrosis (Fig. 6.30).
to rest of the lung producing caseous pneumonia
(Fig. 6.28, A).
Clinical Features and Diagnosis of Tuberculosis

Microscopically, the lesions show exudative reaction with The clinical manifestations in tuberculosis may be variable
oedema, fibrin, polymorphs and monocytes but numerous depending upon the location, extent and type of lesions.
tubercle bacilli can be demonstrated in the exudates However, in secondary pulmonary tuberculosis which is the
General Pathology and Basic Techniques
(Fig. 6.28,B). common type, the usual clinical features are as under:
III. MILIARY TUBERCULOSIS. This is lymphohaemato- 1. Referable to lungs—such as productive cough, may be
genous spread of tuberculous infection from primary focus with haemoptysis, pleural effusion, dyspnoea, orthopnoea
or later stages of tuberculosis. The spread may occur to etc. Chest X-ray may show typical apical changes like pleural
systemic organs or isolated organ. The spread is either by effusion, nodularity, and miliary or diffuse infiltrates in the
entry of infection into pulmonary vein producing dissemi- lung parenchyma.
nated or isolated organ lesion in different extra-pulmonary 2. Systemic features—such as fever, night sweats, fatigue,
sites (e.g. liver, spleen, kidney, brain and bone marrow) or loss of weight and appetite. Long-standing and untreated

Figure 6.27 Microscopic appearance of lesions of secondary fibrocaseous tuberculosis of the lung showing wall of the cavity.