We report two cases of semi-invasive pulmonary aspergillosis with a thoracic wall extension in the first case and a parietal vasculitis without Aspergillus invasion in the second. Semi-invasive pulmonary aspergillosis is an identifiable entity. It is characterized by impairment of local pulmonary defense mechanisms and/or a mild systemic immunosuppression as well as a slowly progressive course. Pulmonary symptoms are not specific. The thoracic wall involvement subsequent to a contiguous pulmonary lesion occurs rarely and indicates poor prognosis. CT scan improves diagnosis significantly, confirmed by histology and/or by the biopsy growth of Aspergillus. Itraconazole, tolerated better than amphotericin B, is an efficient treatment though prognosis remains poor (28% of deaths). Detection of anti-neutrophil cytoplasmic antibodies (diffuse cytoplasmic staining) evolving conversely to this disease seems to be associated with infectious vasculitis. These antibodies are found in vasculitis and especially in Wegener's granulomatosis with a high specificity. They have also been described in a few patients with infectious diseases.