Case Report: Rhinosporidiosis Literature Review.

Rhinosporidiosis is caused by Rhinosporidium seeberi, a pathogen currently considered a fungus-like parasite of the eukaryotic group Mesomycetozoea. It is usually a benign condition, with slow growth of polypoid lesions, with involvement of the nose, nasopharynx, or eyes. The clinical characteristics of a painless, friable, polypoid mass, usually unilateral, can guide the diagnosis, but the gold standard for diagnosis is histopathological findings. This article reviews the epidemiology, pathobiology, clinical manifestations, diagnostic strategies, and treatment approach for rhinosporidiosis.

Rhinosporidiosis in horses / Rinosporidiose em equinos

Rhinosporidiosis is a disease caused by Rhinosporidium seeberi, an aquatic protist of the class Mesomycetozoa. It primarily affects the nasal mucosa and transmission is associated with contaminated water contact. This report describes seven cases of rhinosporidiosis in horses in Rio Grande do Sul covering the period of 13 years. The disease predominantly affected Crioulo and thoroughbred horses. No apparent gender predisposition occurs, and age ranged from two to 25 years, with a median of 10 years. The gross aspects were characterized by unilateral (85.7%, 6/7) or bilateral (14.3%, 1/7) polyps. These were soft to friable, whitish to pink, cauliflower-like, with an irregular, sometimes ulcerated surface, measuring 2.5 to 6.0cm in diameter. There was a severe inflammatory infiltrate of the submucosa was observed, associated with moderate proliferation of the epithelium, and numerous rounded structures were identified compatible with sporangia of R. seeberi. Rhinosporidiosis should be included in the differential diagnosis of other conditions affecting the respiratory tract of horses, and it is important to perform histopathology for diagnosis.(AU)

A rinosporidiose é uma doença causada por Rhinosporidium seeberi, protista aquático da classe Mesomycetozoa. Acomete principalmente a mucosa nasal e a transmissão está associada ao contato com água contaminada. Este trabalho descreve sete casos de rinosporidiose em equinos no Rio Grande do Sul em um período de 13 anos. A doença afetou predominantemente cavalos de raça, como Crioulo e Puro Sangue Inglês, sem predisposição sexual evidente e a idade variou de dois a 25 anos, com a mediana de 10 anos. Macroscopicamente foram caracterizadas por pólipos unilaterais (85,7%; 6/7) ou bilaterais (14,3%; 1/7). Os pólipos eram macios a friáveis, esbranquiçados a róseos, com aspecto de couve flor e com superfície irregular, por vezes ulcerada, medindo 2,5 a 6,0cm de diâmetro. Havia infiltrado inflamatório piogranulomatoso acentuado na submucosa associado à moderada proliferação do epitélio e numerosas estruturas arredondadas compatíveis com esporângios de R. seeberi. A rinosporidiose deve ser incluída no diagnóstico diferencial de outras patologias que acometem o trato respiratório de equinos, sendo importante a realização da histopatologia para diagnóstico.(AU)

New interpretations in rhinosporidiosis, enigmatic disease of the last nine decades.

Fungal etiology is widely quoted for the disease rhinosporidiosis. Identity of the fungal sporangium and its relationship with the disease have baffled medical scientists and mycologists for several decades. This study provides unequivocal evidence against involvement of fungus in rhinosporidiosis. The so-called sporangium is found to be a unique body containing residue-loaded lysosomal bodies ('spores') for elimination from the system. 'Sporangia' have been redesignated nodular bodies (NB) and 'spores' as spheres of cellular waste (scw). Two carbohydrates, namely defective proteoglycans synthesized intracellularly and an exogenous polysaccharide ingested through diet of tapioca constitute indigestible material in NB and scw. Polysaccharide in NB which has beta, 1-4 glycosidic bonds between mannose residues is not degraded by gastrointestinal enzymes nor in intracellular lysosomes which break only alpha-glycosidic bonds. A link between NB and dry tapioca has been deduced. Rhinosporidiosis is a complex phenotype with perhaps no parallel in medical science. This report erases 99 years (1892-1991) of controversies regarding 'causal organism' of rhinosporidiosis.

Rhinosporidium seeberi and papovavirus infection of the conjunctiva: a clinical and ultrastructural study.

The present study describes, for the first time, the clinical and the ultrastructural findings of a rare case presented with concurrent conjunctival infection of Rhinosporidium seeberi and a papovavirus. In contradistinction to previous reports, the present case lacked the characteristic granulomatous inflammatory reaction of rhinosporidiosis. This finding, together with the frequent recurrence of the lesion, led us to postulate the presence of a Local Acquired Immune Deficiency State (LAIDS). This Local AIDS may be caused by an immunosuppression mechanism which is probably mediated by papovavirus.