Malakoplakia of the maxillary sinus.
The first case of malakoplakia in the nasal cavities is reported. The patient, a 21-year-old man, presented a polypoid formation in the left maxillary sinus that was removed and studied by light and electron microscopy. The polypoid formation consisted of pseudostratified epithelium surrounding a central myxoid tissue which contained fibroblasts, histiocytes, and small inflammatory infiltrates. The most relevant features were histiocyte accumulations containing 1 to 5-microns diameter granules which displayed a concentric multilayered configuration. Ultrastructural findings revealed three types of lysosomes within the histiocyte cytoplasm: phagolysosomes, intermediate bodies, and Michaelis-Gutmann bodies. Septate junctions between lysosomes were frequent. The etiopathogenesis of this lesion is discussed.
D000328:Adult; D006801:Humans; D008287:Malacoplakia / Q000150:complications / Q000473:pathology*; D008297:Male; D008443:Maxillary Sinus / Q000473:pathology; D008444:Maxillary Sinus Neoplasms / Q000473:pathology; D011127:Polyps / Q000473:pathology; D012852:Sinusitis / Q000209:etiology* / Q000473:pathology