Recurrent rhinosporidiosis in a young male: A case report and its taxonomical journey

Abstract

Rhinosporidiosis is a rarely encountered granulomatous infection caused by Rhinosporidium seeberi affecting both humans and animals. Although the disease has been reported worldwide, it is mainly endemic in tropical and subtropical countries. In the Indian subcontinent, it is endemic in some parts like Orissa, Tamil Nadu, Kerala, eastern Madhya Pradesh, and Chhattisgarh. It is a chronic granulomatous disease with varied controversial taxonomical history, but recently based on genetic sequencing and the nature of aquatics, it was later identified as an aquatic eukaryote. The mucous membranes are frequently impacted in humans, with a typical manifestation being the presence of a polypoidal mass. The occurrence of Rhinosporidiosis in nonendemic regions is uncommon. We report one such case of a young male with recurrent Rhinosporidiosis from India.

INTRODUCTION

Rhinosporidiosis is a chronic localized granulomatous disease caused by a hydrophilic organism Rhinosporidium seeberi. It has been misplaced in different taxonomic categories over years; recently, it has been classified as an aquatic eukaryote based on the genetic sequencing and nature of aquatics.[1,2] This is the primary reason for the prevalence reported from tropical and subtropical regions of the world where stagnant water is the source of Rhinosporidium.[1,3] The disease is rarely encountered in North India; cases have been sporadically reported from Eastern and Central India. The disease is characteristically associated with formation of polyps/polypoidal friable vascular masses most commonly affecting the nasal and nasopharyngeal mucous membranes. The causative organism R. seeberi cannot be cultivated in the culture media; thus, histopathology of the lesion is the gold standard for diagnosis. The unusual nature and rare occurrence of this disease particularly in the nonendemic regions and inevitability of histopathological examination for diagnosis prompted us for the formulation of this study.

CASE REPORT

A 20-year-old male reported to the outpatient department of a tertiary care hospital with the complaint of nasal bleed and nasal obstruction. The patient gave a history of removal of some lesions in the nose few years back by a local physician, but no histopathological examination was done for them. There was no associated history suggestive of anosmia or bathing in ponds/stagnant water. There was no such history in any of his family members. A general physical and systemic examination revealed no abnormalities. The patient underwent nasal endoscopy, in which a friable mass was seen in the nasal cavity on the right side attached to the lateral wall of the nasal cavity. The left side and oropharyngeal region was unremarkable. Blood examination was unremarkable; complete blood count revealed mild eosinophilia, while other routine biochemical parameters were within normal limits. The patient was planned for endoscopic excision of the mass which was submitted for histopathological examination for diagnosis. The specimen submitted comprised multiple gray white to gray brown fragile soft tissue bits together measuring 4 cm × 3 cm × 2 cm. The microscopic sections revealed numerous mature large thick-walled sporangia with numerous endospores approximately 6–10 μ each and immature sporangia with giant cell reaction around ruptured sporangia and dense acute on chronic [Figure 1a,b] inflammation with overlying hyperplastic respiratory and squamous epithelium and foci of calcified spores. Grocott methenamine-silver (GMS) and periodic acid-Schiff (PAS) [Figure 1c,d] diastase stains were positive in sporangia and spores. The features were consistent with Rhinosporidiosis. Postoperatively, the patient was instructed to not to take bath in a pond/lake/any stagnant water body. The patient has been on follow-up for the last 2 years without any recurrence till date.

Figure 1.

Photomicrographs showing: (a)Numerous thick walled sporangias with surrounding giant cell reaction (HE 40x), (b)Sporangias containing endospores (HE 40x), (c)Endospores and sporangia wall positive for PAS-D (100x), (d)Endospores and sporangia wall positive for GMS (100x)

DISCUSSION

R. seeberi, previously thought to be a fungus, belongs to the aquatic protozoa family and is the primary etiological agent for Rhinosporidiosis.[1] This organism was named after the R. seeberi, who first described this lesion in Argentina and identified a causative agent as a possible etiology, based on the clinical presentation.[3] R. seeberi was discovered in early 1900s by Seeberi, who analyzed its sporangium structure and believed it to be a member of Coccidia group family. After that, this organism was positioned in the taxonomy of fungus staring from lower fungus (phycomycetes) to ascomycetes fungus owing to similarity of sporangia to multispored asci. Some researchers pointed out similarities between R. seeberi and aquatic parasites like Ichthyophonus and Dermocystidium. Most of the microbiologists presumed it as a fungus due to its ability to stain with fungal stains like GMS and PAS.[3,4] Sequence analysis of 18S small-subunit (SSU) ribosomal DNA (rDNA) (GenBank accession no. AF118851) placed it within a recently described fish parasite group DRIP (Dermocystidium-Rosette agent-Ichthyophonus-Psorospermium) clade that proposed to rename as Mesomycetozoa.[4] Therefore, because of taxonomic controversies, R. seeberi has been considered in a wide range as protozoan, fungus, and cyanobacterium.[1,4]

The disease is commonly reported from tropical and subtropical areas, especially of Asian countries.[5,6] Rhinosporidiosis has a long incubation period before first clinical manifestation, thus shadowing the exact point/source of infection. Researchers also discovered that this microbe lives in a water reservoir as well as contaminated soil using fluorescent in situ hybridization techniques. Thus, water and soil are considered to be the reservoir of infection, with the latter’s increased incidence in sand workers, paddy cultivators, and people bathing in stagnant waters.[7] In the present study, the patient was from an Indian State with slight endemicity for the incidence of Rhinosporidium. Although the patient gave no history pertinent to exposure/contamination by this organism in the recent past, he did mention briefly about bathing in ponds a few times during early childhood.

In their study on nasal rhinosporidiosis, Guru et al.[8] reported the most common involvement of the lateral wall of the nose, followed by the septum and floor. In another study, Karthikeyan et al.[9] found the septum, followed by the inferior turbinate and inferior meatus, as the most common site of attachment.[10] In the case being discussed presently, the nasal mass was involving the right lateral wall of nasal cavity.

The first-line treatment is total surgical excision and electrocauterization of base of polyp. However, recurrence of the lesions has been frequently reported. Various authors have reported ineffectiveness of antifungal agents as treatment modality. In a study by Doddawad et al., use of Dapsone therapy provided complete remission for a year in Rhinosporidiosis patients. It is stipulated that Dapsone works by preventing the maturation of the sporangia and promoting fibrosis in the stroma.[3] Our patient also gave a history of removal of some nasal lesions in the past, but no pathology report was available. After the latest complete excision, there has been no report of any recurrence.

CONCLUSION

Rhinosporidiosis though endemic in nature needs to be considered a probable differential diagnoses in the masses involving nasal cavity without bleeding. A thorough history and identifying the characteristic histological findings are critical to attain a correct final diagnosis. Rhinosporidiosis can be diagnosed with a simple examination of hematoxylin and eosin-stained histopathological sections. Laser-assisted endoscopic excision, in combination with Dapsone, is the recommended treatment for Rhinosporidiosis. The apt and correct diagnosis will prevent unnecessary recurrences and frequent interventions to the patient.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.