Microcystis aeruginosa as the causative organism of rhinosporidiosis

Disseminated rhinosporidiosis masquerading as soft tissue round cell tumour diagnosed by fine needle aspiration cytology

Rhinosporidium seeberi belongs to the eukaryotic class Mesomycetozoea and causes chronic granulomatous lesions known as rhinosporidiosis. Rhinosporidiosis frequently involves the nasal cavity and nasopharynx through transepithelial invasion. Atypical presentations of this disease at other body sites have been reported, including the subcutis, visceral organs, bones, and genitals. Only a few cases of cutaneous and subcutaneous involvement have been reported to date. This chronic granulomatous condition is known for its recurrence following autoinoculation unless the correct diagnosis and appropriate treatment are given. We describe a case of an immunocompetent adult who had undergone fine needle aspiration cytology (FNAC) of mass-like swellings in the right thigh and right calf at another healthcare centre and had been diagnosed with a small round blue cell tumour. FNAC at our centre confirmed a rare case of rhinosporidiosis that was clinically mimicking a soft tissue neoplasm of the lower extremity, and the erroneous interpretation of the prior cytology studies had resulted in misinterpretation of the individually dispersed pathogenic organisms as individual malignant cells. FNAC of rhinosporidiosis can lead to early diagnosis and prompt treatment of this pathogen when it presents at unanticipated body sites.

Rhinosporidiosis presenting as an oropharyngeal mass: A clinical predicament?

Rhinosporidiosis, is a chronic granulomatous disease presenting as a polypoidal mass in the nasal cavity and nasopharynx caused by Rhinosporidium seeberi and is endemic in India and Sri Lanka. Diagnosis is mainly by clinical observations and is confirmed by histopathology. We report a case of atypical rhinosporidiosis that presented as an oropharyngeal mass and mimicked chronic tonsillitis. Hence possibility of this atypical rhinosporidiosis should be included in the clinical differential diagnosis of any posterior oral or oropharyngeal mass, particularly when managing patients from rural endemic areas.

Rhinosporidiosis in the parotid duct: a rare case report

Endemic to South India and Sri Lanka, Rhinosporidiosis is a chronic granulomatous infection caused by an agent of uncertain taxonomy: Rhinosporidium seeberi. Although it commonly manifests as a proliferative nasal lesion, many cases of Rhinosporidiosis have been reported where it has appeared as an extranasal lesion. The reported extranasal sites include the eye, ear, trachea, and parotid duct. However, the involvement of the parotid duct is quite rare, even among extranasal sites. The case presented is an adult female from the non-endemic zone of East India with a proliferative mass in the parotid duct. Although Rhinosporidiosis was not taken into consideration in the clinical differential diagnosis, eventual histopathological diagnosis confirmed Rhinosporidiosis. As this appears to be the second case of Rhinosporidiosis in the parotid duct in East India in 4 years, we encourage clinicians to be flexible in the differential diagnosis of proliferative growth in the parotid duct, even in those from non-endemic areas.

Rhinosporidiosis in Delhi, north India: case series from a non-endemic area and mini-review

We report three cases of rhinosporidiosis from migrant population of Delhi. Three male patients had sino-nasopharyngeal, nasopharyngeal and nasal rhinosporidiosis, respectively. One patient gave a history of bathing in stagnant water. The diagnosis was made by clinical presentation and microscopic observation of characteristic sporangia of Rhinosporidium seebri in mycological and histopathological investigations. All the patients were successfully treated with complete surgical excision of lesions and cauterization of base. There were no recurrences.

Human nasal rhinosporidiosis: an Italian case report

BACKGROUND

Rhinosporidiosis is a disease affecting primarily the mucosa of nose, conjunctiva and urethra. It is endemic in some Asiatic regions, affecting people of any age and sex. Its manifestation is a polypoid mass growing inside the affected cavity and the only treatment is surgical excision. Rhinosporidium seeberi is the aetiological agent. Many discussions arouse regarding the taxonomic classification of the microorganism, recent studies established it is an aquatic protistan parasite. The lesion may recur and sometimes cause osteolytic bone lesions. In endemic areas it is not easy to establish if recurrent lesions are due to relapse or reinfection.

CASE PRESENTATION

A 26-year-old male patient from India, resident in Italy since 2005, presented in March 2006 with a history of nasal obstruction of three months duration. Physical examination showed an erythematous, papillomatous mass, 3 cm in diameter, obstructing the right nasal cavity. A microscopic diagnosis of rhinosporidiosis was made. Few Italian human cases of this disease have been previously reported in the literature.

CONCLUSION

Rhinosporidiosis is a condition which both clinicians and pathologists should keep in mind when managing patients from endemic countries with nasal masses. Moreover, it is very interesting in such cases to follow the clinical course: an eventual recurrence of the lesion in our patient would mean a true relapse, excluding the possibility of a reinfection, more probable in the endemic areas.

Tropical dermatology: fungal tropical diseases

Fungal infections are common in tropical countries and can have an important impact on public health. Lobomycosis is a common fungal infection in the tropical rain forest of South America, and paracoccidioidomycosis (South American blastomycosis) is a widespread and sometimes severe illness. Penicilliosis marneffei is an opportunistic infection of AIDS patients in southeast Asia. Chromoblastomycosis and mycetomas are causes of morbidity around the world. Sporotrichosis is a worldwide subcutaneous mycosis with a high incidence in tropical countries and is an important illness in immunocompromised patients. Rhinosporidiosis was classed as a fungal infection but is now considered a protistan parasite that belongs to the class Mesomycetozoea. It is included in this review because of its historical classification. In the past, most of these mycoses were restricted to specific geographic areas and natural reservoirs. There are, however, situations in which people from other regions come in contact with the pathogen. A common situation involves an accidental contamination of a traveler or worker who has contact with a tropical mycosis. Even minor trauma to the skin surface or inhalation of the fungal conidia can infect the patient. Thus recognition of the clinical symptoms and the dermatologic findings of the diseases, as well as the geographic distribution of the pathogens, can be critical in diagnosis of the tropical mycoses. This review discusses some of the more common tropical subcutaneous and systemic mycoses, as well as their signs, symptoms, methods of diagnosis, and therapies.

LEARNING OBJECTIVE

At the completion of this learning activity, participants should be able to recognize the clinical and histologic presentations of tropical fungal diseases with cutaneous manifestations and be familiar with the appropriate therapies.

Rhinosporidiosis in Egypt: a case report and review of literature

Rhinosporidiosis is an infection caused by Rhinosporidium seeberi that frequently presents as a polypoidal nasal lesions. Here, we report the first indigenous case of tumoral rhinosporidiosis in Egypt. In this case, a 25-year-old male patient from a rural background of Assuit City presented with epistaxis and a nasal polyp. The patient had not traveled abroad. The diagnosis was established on the morphological basis by the identification of 5- to 10-microm endospores and 50- to 1000-microm sporangia. The clinicopathological and immunologic features were discussed and the literature was reviewed. To the best of our knowledge this is the first case of this disease to be reported in Egypt in the human literature.

Rhinosporidiosis: what is the cause?

PURPOSE OF REVIEW

Significant advances in knowledge on rhinosporidiosis and Rhinosporidium seeberi were made in 1999, 2000, 2003 and 2004. These advances are reviewed on account of the continuing sporadic occurrence of the disease universally, and because of the availability of new approaches that could resolve persisting enigmas of both the disease and its causative pathogen.

RECENT FINDINGS

R. seeberi, the pathogen that causes rhinosporidiosis, has been definitively classified using molecular biological tools in a new clade - the Mesomycetozoea, along with 10 parasitic and saprobic microbes. The controversial spherical bodies of the endospores have been shown to comprise both lipid/protein nutritive bodies and other spherical bodies that are metabolizing units that reduce MTT (3-[4,5-dimethyl-2-thiazolyl]-2,5-diphenyl-2H-tetrazolium bromide). This indicates the viability of these spherical bodies, provisionally identified as the electron dense bodies that have also been shown to contain nucleic acids. MTT reduction as an indicator of viability has been used to determine the sensitivity of rhinosporidial endospores to biocides, antimicrobial drugs, and to specific antibodies. Genetic heterogeneity has been identified in strains from humans and animals. Cell-mediated and humoral immune responses have been demonstrated in human patients and in mice. Several mechanisms of immune evasion by R. seeberi have been identified.

SUMMARY

These findings are applicable in both clinical and laboratory practice, while the basic advances have implications in further work on experimental pathogenicity, the biology of R. seeberi, and on the epidemiology and pathogenesis of rhinosporidiosis.