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Rhinosporidiosis
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.
Studies of Rhinosporidium seeberi have demonstrated that this organism has a complex life cycle in infected tissues. Its in vivo life cycle is initiated with the release of endospores into a host's tissues from its spherical sporangia. However, little
is known about the mechanisms of sporangium formation and endospore release since this pathogen is intractable to culture.
We have studied the in vitro mechanisms of endospore release from viable R. seeberi's sporangia. It was found that watery substances visibly stimulates the mature sporangia of R. seeberi to the point of endospore discharge. The internal rearrangement of the endospores within the mature sporangia, the opening
of an apical pore in R. seeberi's cell wall, and the active release of the endospores were the main features of this process. Only one pore per sporangium
was observed. The finding of early stages of pore development in juvenile and intermediate sporangia suggested that its formation
is genetically programed and that it is not a random process. The stimulation of R. seeberi's sporangia by water supports the epidemiological studies that had linked this pathogen with wet environments. It also explains,
in part, its affinities for mucous membranes in infected hosts. The microscopic features of endospore discharge suggest a
connection with organisms classified in the Kingdom Protoctista. This study strongly supports a recent finding that placed
R. seeberi with organisms in the protoctistan Mesomycetozoa clade.
This paper describes four cases of canine rhinosporidiosis which occurred in Italy in 1994 and 1995. Four dogs with a history of exposure to the muddy environment of rice fields, developed respiratory signs. Rhinoscopy revealed nasal polypoid lesions with a characteristic gross appearance due to the presence of multiple, tiny, white-yellowish spots representing sporangia filled with spores. In cytological samples obtained by brushing, many spores were present in an inflammatory background. Histologically, the polyps consisted of fibrovascular tissue embedding sporangia in different developmental stages, and free spores which elicited a severe pyogranulomatous inflammation. All the dogs were treated surgically and the condition did not recur in two cases during a year's follow-up and in the other two cases during two years.
For the past 100 years the phylogenetic affinities of Rhinosporidium seeberi have been controversial. Based on its morphological features, it has been classified as a protozoan or as a member of the kingdom Fungi. We have amplified and sequenced nearly a full-length 18S small-subunit (SSU) ribosomal DNA (rDNA) sequence from R. seeberi. Using phylogenetic analysis, by parsimony and distance methods, of R. seeberi’s 18S SSU rDNA and that of other eukaryotes, we found that this enigmatic pathogen of humans and animals clusters with a novel group of fish parasites referred to as the DRIP clade (Dermocystidium, rossete agent, Ichthyophonus, and Psorospermium), near the animal-fungal divergence. Our phylogenetic analyses also indicate that R. seeberi is the sister taxon of the two Dermocystidium species used in this study. This molecular affinity is remarkable since members of the genus Dermocystidium form spherical structures in infected hosts, produce endospores, have not been cultured, and possess mitochondria with flat cristae. With the addition of R. seeberi to this clade, the acronym DRIP is no longer appropriate. We propose to name this monophyletic clade Mesomycetozoa to reflect the group’s phylogenetic association within the Eucarya.
Objective.—To study retrospectively the identification, characteristics, and localization of myospherulosis in different types of renal cell carcinomas.
Design.—Twenty-seven consecutive renal cell carcinomas treated by radical nephrectomy in 1 year were studied. All the tumor and nontumor slides were examined for myospherulosis. The demographic data, histological type of renal cell carcinoma, Robson stage, and Fuhrman grades were recorded.
Results.—Myospherules were found in 10 cases. They were associated with the clear cell type and a higher nuclear grade. The cell type remained the only significant factor when these 2 factors were tested together with the tumor stage by logistic regression. Myospherulosis tended to be found in younger patients but was not associated with the sex or the side of the tumor. They were scattered within tumor cystic spaces or among sheets of tumor cells. Some of the myospherules might arise from histiocytes or even tumor cells. Compared with previous reports of myospherulosis associated with exogenous or endogenous lipid, the myospherules associated with renal cell carcinoma were smaller and more uniform in size. There is no associated fibrosis or foreign body giant cell reaction.
Conclusion.—As far as we know, this is the first report of myospherulosis occurring in malignant tumors in human, and their associated features are different from those previously described for myospherulosis related to exogenous or endogenous lipid.
This paper reports a case of rhinosporidiosis which presented with widespread subcutaneous nodular lesions which failed to respond to surgical excision or to intravenous amphotericin B. Lesions in sites away from the nasal cavities are usually believed to be brought about by direct infection or by fingerborne autoinoculation. In this case, haematogenous dissemination was shown by the presence of sporangia within the lumen of a blood vessel. Systemic rhinosporidiosis is an extremely rare condition.
Rhinosporidiosis, a chronic granulomatous infection due to Rhinosporidium seeberi, is reported to be endemic to India. It frequently involves the nasal passages, and infection at other sites, like ocular tissues, lip, urethra, larynx, rectum, and skin, although rare, has been reported. Generalized involvement of the skin is extremely uncommon. In such cases the spread of infection is thought to be due to autoinfection, caused by scratching the skin by fingers contaminated from the primary site. In a review of the available literature, we could come across only one case of generalized rhinosporidiosis due to hematogenous dissemination, producing visceral involvement.8 We are reporting the second case of this nature because of its extreme rarity. Besides the generalized involvement of the skin, this case showed involvement of tongue, larynx, epiglottis, ocular tissues, liver, lungs, kidney, and spleen.
Report of Case
A Hindu man, aged 30
Introduction:
Rhinosporidiosis primarily affects the mucous membranes of the nose and nasopharynx. The disseminated form of this chronic fungal disease is extremely rare.
Case report:
The authors present a case of disseminated rhinosporidiosis in an immunocompetent patient with involvement of the skin, subcutaneous tissue, muscle, bone, penis and urethra, and with a long-standing primary lesion in the nose.
Discussion:
A late or atypical presentation of rhinosporidiosis may cause diagnostic dilemma. Fine needle aspiration cytology of the tumoural lesions may establish the diagnosis. Histopathology is confirmatory. The subcutaneous masses may be solid or cystic. Ulceroproliferative lesions need to be differentiated from malignancies.
Conclusion:
This is the first reported case of truly disseminated rhinosporidiosis with simultaneous involvement of multiple anatomically unrelated sites in a single patient. This is also the first reported case of cystic rhinosporidiosis. The possibility and sequelae of spontaneous regression of rhinosporidiosis are also discussed.
In the skin of Rana temporaria from Czechoslovakia two unicellular parasites have been found: Dermocystidium ranae Guyénot & Naville and Dermosporidium granulosum n.sp.
Dermocystidium ranae . Two stages were found, one of which is new. An account is given of the morphology, development and occurrence of both stages, including details which have hitherto not been recorded.
Dermosporidium granulosum n.sp. This species is represented by cysts situated in the stratum spongiosum corii. They are divided by septa into small chambers containing groups of spherical spores with a central nucleus and with numerous small cytoplasmic inclusions. Within the cyst, the sporoblasts occupy the periphery, while the ripe spores are in the centre.
Purpose. Although conjunctival rhinosporidiosis is endemic in India, associated scleral melting and staphyloma formation are quite rare. We report clinical features and management in three patients with this unusual presentation.
Methods. Retrospective review of case records of three patients with conjunctival rhinosporidiosis.
Results. Infection occurred in young, healthy adults and was localized to the forniceal conjunctiva in all patients. The affected conjunctiva had numerous grey-white spherules, but a polyp-like lesion was not present in any patient. Diagnosis was based on clinical features and examination of scrapings from the involved conjunctiva. Treatment was surgical, with excision of infected conjunctival tissues and staphyloma repair with homologous sclera or autogenous periosteum. Failure to recognize the conjunctival pathology in one patient resulted in recurrence of the staphyloma.
Conclusion. Conjunctival rhinosporidiosis can be associated with scleral staphyloma in young, healthy, adults. Differentiating this entity from idiopathic scleral ectasia requires knowledge of the clinical features of conjunctival rhinosporidiosis and a high index of clinical suspicion.
Summary Observations on the ultrastructural features of Rhinosporidium seeberi are presented. The life cycle is described in which the development of nucleated spores from laminated bodies is traced. In contrast to general opinion and to our previous observations, the spore is demonstrated to be a uninucleated structure. The name of sporoblast is justified to indicate that it is the precursor of the trophocyte.
A Case of Multiple Rhinosporidiosis - Volume 67 Issue 1 - A. F. Desmond
We investigated the immunolocalization of Rhinosporidium seeberi's antigens using sera from individuals infected with R. seeberi and tissue from Sri Lankan patients with rhinosporidiosis. The tissues were fixed in LR white resin, thin sectioned, fixed onto nickel grids and evaluated by transmission electron microscopy for the presence of R. seeberi's sporangia. The tissue samples were reacted with the patients's sera and then labeled with protein A colloidal gold (PACG) for immunolocalization. It was found that the PACG had fixed to antibodies that specifically recognized an internal electron lucent layer situated immediately under the mature sporangium's wall. Strikingly, the endospores, the juvenile and intermediate sporangia did not undergo PACG labeling. This study found that the expression of this antigen occurs only in the final developmental stages of R. seeberi's mature sporangia. Our data may explain why circulating antibodies to R. Seeberi were not detected before in studies that used endospores as antigen in immunoassays. This is the first report in which an antigenic material with a potential role in the immunology of rhinosporidiosis has been detected.
This study of the nature and functional significance of the spherules that develop in sporoblasts show them to participate in the germination of Rhinosporidium seeberi and are the precursors of the trophocytes.
Rhinosporidiosis is a fairly common problem for the Otolaryngologist in many parts of the world, because of its prompt recurrence after surgical excision. Though not a fatal disease, it inflicts various kinds of social and economic strain on the patients and their families.
No medical treatment has been found to be effective in controlling rhinosporidiosis. Such drugs as griseofulvin and amphotericin have been tried without much benefit. In this clinical trial with dapsone on 32 patients, 20 patients (71.4%) did not have recurrence in a three year period and none of them needed surgery in that period. Thirty-two patients were used as controls, and 93% of them needed surgery for recurrent rhinosporidiosis in the same three year period.
Dapsone (diaminodiphenylsulfone) is a relatively safe drug to use, and no major side effects were noticed in this trial.
This is the first report of Rhinosporodiosis from J and K State. It includes 19 indigenous cases of nasal rhinosporodiosis, including 17 males and 2 females, seen over a period of less than three years. All the cases underwent surgical excision of the lesions and during a follow up varying from a few months to less than three years, there have been no recurrences.
A cystic swelling over the right frontal bone above the medial half of the eyebrow in a 37 year old male was found to be caused by Rhinosporidium seeberi. The patient did not have any past or concurrent lesion which could be presumed to be due to Rhino-sporidiosis. The lesion was subcutaneous with overlying healthy skin and had caused erosion of underlying bone.
A case of multiple recurrent Rhinosporidiosis with lytic lesions in the bones of hand and foot are reported. To the best knowledge of the authors this is the first reported case of Rhinosporidiosis with lytic lesions in bones other than of the nose.
The endosporulation phase of Rhinosporidium seeberi is the part of the life cycle most vulnerable to drug therapy. The laminated body formed from the precleavage sporangium has double-membraned tubular and vesicular structures within concentric layers. Similar tubular structures are also found in the developing sporoblast. The development of trophocytes involves three distinct phases. The early trophocyte retains many of the characteristics of the sporoblast as well as endoplasmic reticulum and other radiating filamentous structures in the cell wall. The itermediate tropocyte is larger (20 mug to 30mug m) and contains lipid bodies and microbodies, whereas the mature trophocyte is smaller (7mug m to9mug m) and microbodies are sparse or absent.
• A case of nasal rhinosporidiosis occurred in a 73-year-old man who has lived all his life in the United States. The lesion was treated surgically, and he remains free of disease four years later.
(Arch Otolaryngol 102:308-310, 1976)
The cellular immune response of 8 patients from the Brazilian Amazon region with chromoblastomycosis was analyzed. Primary immunological responses of patients were tested by contact sensitization to 2,4-dinitro-chlorobenzene (DNCB), or rejection of first set skin allografts. 2 of 8 patients were reactive to DNCB after sensitization, and skin allograft rejection occurred in an average of 14 days. Capacity of patients to mount recall immunological responses was measured by skin testing with two fungal antigens and three bacterial antigens. Delayed skin reaction to trichophytin and candida antigens was negative in the majority of the patients. However, reactivity to mycobacterial (tuberculin), and bacterial (staphylococcal, streptococcal) antigen was high, or only slightly diminished respectively. The data suggest that patients with chromoblastomycosis have suppressed nonspecific, cell mediated immunity for some antigens (skin allografts, DNCB, fungal antigens), while reactivity to bacterial and mycobacterial antigens is not impaired.
Rhinosporidiosis is a chronic infection which is endemic in India and Sri Lanka. Penile involvement in rhinosporidiosis is rare and we report one such case. The pathology, treatment and possible etiology of the condition are reviewed.
One hundred and thirty-nine cases of rhinosporidiosis diagnosed histopathologically over a period of 4 years were analysed. Nasal rhinosporidiosis is common among males who bathe in stagnant ponds while ocular rhinosporidiosis is common among urban females. There is a seasonal variation in the incidence of nasal and ocular rhinosporidiosis.
Rhinosporidiosis is an inflammatory disease of the nasal mucosa caused by Rhinosporidium seeberi. The disease is endemic in India but very rare in Europe or other continents. The literature concerning aetiology, clinical appearance, morphology and treatment is reviewed. All reported European cases are summarized.
Two clinically suspected cases of nasal rhinosporidiosis were studied cytologically using a wipe out technique. The smears showed the typical spores of the fungus and the cytological diagnosis of rhinosporidiosis was confirmed by excisional biopsy. The smear is recommended as a routine preliminary screening technique in the diagnosis of suspected cases of rhinosporidiosis.
Phase contrast microscopic study indicated the multilayered structure of the sporangial wall of R. seeberi while the scanning electronmicroscopic study revealed a trilaminated wall compared to a thick double walled light microscopic structure. The scanning electronmicroscopy revealed the spores of varying sizes which were found either discretely or in groups interconnected and seen attached to the inner aspect of the sporangial wall. Autofluorescence of sporangia and spores was observed under microscope. Acridine orange staining revealed the presence of DNA materials in the spore and sporangia.