PATHOLOGICAL FEATURES OF INVASIVE ORAL ASPERGILLOSIS IN PATIENTS WITHHEMATOLOGIC MALIGNANCIES

Purpose: Little is known about the characteristic macroscopic and micr oscopic changes that take place during the progression of oral invasiv e aspergillosis in immunocompromised patients. The aim of this study w as to determine the relationship between the oral and histopathologic findings in these patients. Such a study would aid in understanding th e early development and subsequent progression of the disease. Patient s and Methods: Twelve patients with hematologic malignancies who devel oped invasive oral aspergillosis were studied. The condition was divid ed into three stages according to the oral findings at the time biopsy procedures were performed. Tissue sections from biopsy specimens were stained with hematoxylin and eosin for histopathologic study and the findings were evaluated in relation to the oral findings. Fungal cultu res of biopsy specimens were also performed to confirm the causative o rganisms. Results: The diagnosis of oral aspergillosis was established in terms of both histologic and microbiologic evidence in all 12 pati ents. In the early stage (three patients), isolated areas of violaceou s marginal gingiva consisted of degenerated epithelium and connective tissue infiltrated by fungal hyphae. In the advanced stage (four patie nts), the violaceous marginal gingiva had become transformed into gray necrotic lesions that extended to the attached gingiva. The necrotic lesions showed ulceration and were covered by a pseudomembrane contain ing fungal hyphae. At the base of the ulcers, connective tissue was oc cupied by proliferating fungal hyphae, with vascular invasion being ob served. In the late stage (five patients), the ulcerated lesions had p rogressed, showing destruction of the alveolar bone and surrounding fa cial muscles, with infiltration of fungal hyphae unto the tissues. No inflammatory cellular reaction was observed until the hematologic stat us of the patients improved. Conclusion: These findings indicate that invasive oral aspergillosis has three distinctive clinicopathological stages. Recognition of the different stages of invasive Aspergillus in fections is helpful for correct diagnosis of the disease.