Bronchocentric granulomatosis and allergic bronchopulmonary aspergillosis

Considerable clinical and radiologic similarity exists among FB, ABP, MIB, ABPA, and, to a lesser extent, BCG. In the absence of focal obstructive lesions such as tuberculosis or neoplasm, one of the diffuse bronchial hypersecretory diseases, that is, bronchial asthma, acute or chronic bronchitis, asthmatic bronchitis, or cystic fibrosis, is prerequisite to the development of a clinical and radiologic syndrome, resulting from bronchial mucus retention. This hypersecretory bronchial obstruction syndrome characterizes each of the disorders discussed. Thus, the differences existing among these disorders are merely those of size and location of mucus plugs or casts, and there is substantial variation within each individual entity concerning even this aspect. Unfortunately, extensive efforts to elucidate immunopathogenesis exist only for ABPA. Although evidence for the immunologic and morphologic presence of fungi, particularly AF, in ABPA is quite compelling, it is not necessarily conclusive evidence for an etiologic role of AF in the immunopathogenesis of this disorder. In this regard, it is reasonable to speculate that, perhaps, similar immunologic and morphologic information exists for FB, ABP, MIB, and, in some cases, BCG. BCG, because of its unique intrinsic bronchial obstructive and destructive histopathology, is a disorder distinct from the others, though sharing common clinical and radiologic features in some instances. If Aspergillus is involved in the immunopathogenesis of this disease, it cannot be the only etiologic factor, since in many instances no evidence of its presence is found.