Rhinosporidiosis is a chronic granulomatous disease caused by Rhinosporidium seeberi, an aquatic protistan parasite of the family Mesomycetozoea [1]. It is reported as a hyperendemic disease in Sri Lanka and southern India, where association with stagnant water bodies has been seen more [2]. The nasal mucosa is most commonly affected, but ocular involvement has been reported in about 14% of cases [3].

Ophthalmic rhinosporidiosis usually presents as polypoid, vascularized conjunctival lesions with characteristic pale-yellow spherules of mature sporangia [4]. Diagnosis is made histopathologically, and because complete surgical excision with cauterisation of the base to reduce recurrence, its treatment options are simple. Although ocular rhinosporidiosis is clinically significant in endemic areas, it has been poorly reported, and less information regarding its public health significance is available [5]. With this background in mind, we report ten cases of ocular rhinosporidiosis from a tertiary care hospital. It highlights their clinical presentations, surgical management, and the broader need for preventive public health measures in endemic communities.

Patient information: This retrospective case series was conducted in the Department of Ophthalmology at a tertiary care teaching hospital from March 2024 to August 2024—patients presented with conjunctival masses affecting one or both eyes. Conjunctival masses clinically suggestive of rhinosporidiosis were evaluated (Figures 1 and 2). Data regarding demographic details, clinical features, and water exposure were collected.

All lesions were excised under local anesthesia with a 2 mm margin and base cauterisation

Postoperatively, topical antibiotic and lubricant drops were given for one week. Follow-up data were recorded on days 1 and 7, at one month, and six months post-surgery. Visual acuity was unaffected, and no patient had any visual axis involvement.

There were 10 patients in total, nine males and one female. The age range was 6 to 17.

All patients had a history of swimming in stagnant ponds. They presented with a reddish, vascular, fleshy, pedunculated granular mass with yellowish pinhead-sized nodules on the surface.

Seven cases were bilateral, and 2 had nasal involvement. The lower tarsal conjunctiva was the most common site (53.3%), followed by the upper tarsal conjunctiva (26.6%).

Visual acuity remained stable for all patients throughout the study period. Under local anesthesia, each conjunctival growth was excised and its base cauterized. All resected samples were submitted for Histopathological Examination (HPE) and microbiological work-up to provide comprehensive supportive evidence. Following tissue processing, wet mounts prepared in 10% KOH solution revealed vascular fibromyxomatous connective tissue, lined by stratified squamous epithelium, and the causative pathogens in various developmental stages. Histopathological examination corroborated this, confirming rhinosporidiosis by identifying characteristic thick-walled sporangia with endospores at different maturational stages.

Despite being endemic in specific geographic regions, ocular rhinosporidiosis remains an underreported clinical entity [6]. The demographic profile in this case series—predominantly male children—mirrors patterns described in previous literature, which note a higher incidence among males and a usual age of presentation between 10 and 40 years [7]. Rhinosporidiosis most frequently involves the nasal cavity and nasopharynx (70–85% of cases), followed by ocular involvement (9–15%), and more rarely, the urethra, ear, or bones [8]. The conjunctiva (50–77.6%) and lacrimal sac (24–33%) are the most commonly affected sites within the ocular structures [9].

In our study, the lower tarsal conjunctiva was the most frequently involved location (53.3%), consistent with prior reports [10]. Transmission is believed to occur through direct contact or autoinoculation, potentially spreading to ocular tissues via the lacrimal sac or plica semilunaris. All patients elicited a clear and consistent history of exposure to stagnant pond water, underscoring the significance of environmental risk factors in disease transmission. It is hypothesized that chemical constituents and microbial synergy within stagnant water may enhance the survival and infectivity of Rhinosporidium seeberi.

Definitive diagnosis relies on histopathological examination and supportive microbiological analysis. In our series, hematoxylin and eosin (H&E) staining demonstrated characteristic thick-walled sporangia at various stages of development within a vascular fibromyxoid connective tissue matrix lined by stratified squamous epithelium. KOH mounts further supported the diagnosis.

Medical therapy alone has shown limited efficacy in managing rhinosporidiosis [11]. Complete surgical excision with base cauterisation remains the gold standard, as the current study highlights. Although dapsone has been used adjunctively to inhibit sporangial maturation and reduce recurrence rates—by interfering with folate metabolism and inducing early degeneration—none of our patients received this pharmacologic intervention. One recurrence was observed during the follow-up period, likely attributable to microscopic subepithelial remnants. This reinforces the importance of meticulous surgical technique to ensure complete lesion removal.

Differential diagnoses include papilloma, hemangioma, pyogenic granuloma, and other vascular malformations. A distinguishing clinical hallmark of rhinosporidiosis is the presence of pale-yellow spherules (sporangia) on the lesion surface, which may aid in early suspicion and diagnosis.

Public health strategies are imperative because of the established link between environmental exposure and disease acquisition. Community-based interventions promoting water hygiene, education on avoiding high-risk water sources, and improved sanitation could reduce disease incidence and recurrence.

Ocular rhinosporidiosis is an under-recognized clinical entity frequently misdiagnosed, particularly in non-endemic regions. While the disease remains endemic in select countries such as India and Sri Lanka, sporadic cases have been reported globally. In patients presenting with polypoidal conjunctival masses—especially in endemic areas—ocular rhinosporidiosis should be included in the differential diagnosis, regardless of geographic location.

Given the strong association with exposure to stagnant water, preventive measures such as avoiding contaminated water sources and raising community awareness are essential. Although clinical presentation may be suggestive, definitive diagnosis requires histopathological and microbiological confirmation to differentiate it from other vascular or granulomatous lesions. Complete surgical excision with wide base cauterisation remains the cornerstone of management, offering excellent outcomes with minimal recurrence when meticulously performed. Long-term follow-up is advised to detect potential recurrences arising from residual microscopic disease.

1. Sánchez, A., Arias, S., & Samudio, C. (2020). Case Report: Rhinosporidiosis, Case Report, and Literature Review. The American journal of tropical medicine and hygiene. https://doi.org/10.4269/ajtmh.20-0291.
2. Meethal, S., Kumar, K., & Dilna, N. (2020). Rhinosporidiosis – A Clinical Survey.
3. Alam, M., & Shrirao, N. (2022). Clinical Spectrum and Management Outcome of Ocular and Adnexal Rhinosporidiosis. Journal of Current Ophthalmology, 34, 341 - 346. https://doi.org/10.4103/joco.joco_33_22.
4. Penagos, S., Zapata, N., Castro, J., Hidrón, A., & Agudelo, C. (2021). Rhinosporidiosis in the Americas: A Systematic Review of Native Cases. The American journal of tropical medicine and hygiene. https://doi.org/10.4269/ajtmh.20-1411.
5. Varghese, L., Kurien, R., Susheel, S., Cherian, L., Rebekah, G., & Rupa, V. (2021). Rhinosporidiosis—Factors predicting disease recurrence. Mycoses, 64, 1471 - 1479. https://doi.org/10.1111/myc.13381.
6. Alam, M., & Shrirao, N. (2022). Clinical Spectrum and Management Outcome of Ocular and Adnexal Rhinosporidiosis. Journal of Current Ophthalmology, 34, 341 - 346. https://doi.org/10.4103/joco.joco_33_22.
7. Mathew, S., Arora, R., Prabha, N., Kamble, P., Satpute, S., & Nagarkar, N. (2020). Retroanalytical Study of Epidemiological Factors of Rhinosporidiosis. International Archives of Otorhinolaryngology, 25, e504 - e508. https://doi.org/10.1055/s-0040-1718526.
8. Panicker, V., Jyothikumar, N., Sajitha, M., Venugopal, K., Kallarackal, J., & Parameswari, R. (2023). A rare case of disseminated and recurrent rhinosporidiosis. PULMON, 25, 64 - 67. https://doi.org/10.4103/pulmon.pulmon_23_23.
9. Alam, M., & Shrirao, N. (2022). Clinical Spectrum and Management Outcome of Ocular and Adnexal Rhinosporidiosis. Journal of Current Ophthalmology, 34, 341 - 346. https://doi.org/10.4103/joco.joco_33_22.
10. Adhikari, A., Dutta, J., Das, S., Barua, N., Chakraborti, C., & Chakraborti, P. (2022). Ocular Rhinosporidiosis and Recurrence Postsurgery: A Case Series. JOURNAL OF CLINICAL AND DIAGNOSTIC RESEARCH. https://doi.org/10.7860/jcdr/2022/50398.15822.
11. Biradar, K., Kumar, S., Singh, R., Dutta, A., Walia, I., & Kumar, M. (2023). Management of Rhinosporidiosis: by Coblation. Indian Journal of Otolaryngology and Head & Neck Surgery, 76, 1398-1401. https://doi.org/10.1007/s12070-023-04155-9.