Scleroma (Rhinoscleroma). A histologic immunohistochemical study with bacteriologic correlates.

Scleroma was diagnosed in nine of 30 Spanish-surnamed patients who had inflammatory lesions of the nose, pharynx, and larynx during the two-year period from Jan 1, 1978, through Dec 31, 1979. A total of 19 biopsy specimens were taken from these nine patients. In six of the 19 specimens, a histologic diagnosis of scleroma was not possible. Seventeen of the specimens with characteristic histologic findings stained with the peroxidase-antiperoxidase method for detection of Klebsiella capsular antigen III, although in 11 of these specimens, simultaneous cultures failed to reveal the characteristic Klebsiella rhinoscleromatis. These specimens showed the features of one of the three histopathologic forms of scleroma: ozena, granuloma, or scleroma. A range of tissue reactions was identified: histiocyte and plasma cell nodules, vasculitis, acute inflammation, pseudoepitheliomatous hyperplasia, ulceration, and submucosal keratin cyst. Comparison with histochemical bacterial stains revealed that the PAS and Hotchkiss-McManus stains gave unequivocal positive results less frequently than the immunoperoxidase method, and were less specific. Methenamine silver, Giemsa, Deiterle, Brown and Brenn, and Brown and Hopps were unreliable for the detection of the organism. The immunoperoxidase method can be appropriately used when the spectrum of histopathologic findings suggests a differential diagnosis of scleroma.