Myospherulosis. An electron-microscopic study of a human case.

An electronmicroscopic study of a human case of myospherulosis, which involved the nose and maxillary sinus, is reported. Large parent bodies limited by a thick electron-dense wall, enclosing variable numbers of spherules, were seen in cystic tissue spaces or adjacent connective tissue. Free spherules and shrunken degenerative forms were present as well. Similarity of these bodies to sporangium-like structures is suggested. The etiology of the disease remains unsettled.