Disseminated Rhinosporidiosis Presenting as a Patellar Mass: A Case Report
DOI:
https://doi.org/10.21276/apalm.3873Keywords:
rhinosporidiosis, bone involvement, patella, synovium, rhinosporidium seeberi, granulomatous infectionAbstract
Background: Rhinosporidiosis is a chronic granulomatous disease caused by *Rhinosporidium seeberi*, an aquatic protistan organism belonging to the class Mesomycetozoea. Although the nasal mucosa is the most commonly involved site, dissemination to bone is exceedingly rare, with patellar involvement being exceptionally uncommon and often mimicking malignancy. Case Presentation: A 55-year-old male presented with slowly progressive swelling over the left patellar region. He had a history of recurrent scalp rhinosporidiosis treated surgically over two decades. Clinical examination revealed multiple polypoidal skin nodules over the trunk and extremities. Radiographs showed a lytic lesion involving the patella, and MRI suggested a primary bone malignancy. However, histopathological examination of tru-cut biopsy followed by patellectomy revealed numerous thick-walled sporangia containing endospores infiltrating the synovium and bony trabeculae, confirming disseminated rhinosporidiosis.Conclusion: Osseous rhinosporidiosis is an extremely rare entity that can closely mimic aggressive bone tumours radiologically. Histopathological examination remains the gold standard for diagnosis. Awareness of such atypical presentations, particularly in endemic regions, is essential to avoid misdiagnosis and ensure appropriate management.
References
1. Arias AF, Romero SD, Garcés CG. Rhinosporidiosis: literature review. Am J Trop Med Hyg. 2021;104(2):708–711.
2. Kundu AK, Phuljhele S, Jain M, Srivastava RK. Osseous involvement in rhinosporidiosis. Indian J Orthop. 2013;47(5):523–525.
3. Kar BK, Banchhor R, Thakur RPS, Mohanty D, Monga N. Rhinosporidiosis with musculoskeletal manifestation: a case series. Indian J Orthop Surg. 2018;4(4):405–410.
4. Goswami R. Rhinosporidiosis in relation to bizarre presentation and mode of dissemination. Int J Med Res Rev. 2014;2(1):58–62.
5. Chowdhury RK, et al. Disseminated rhinosporidiosis: clinicopathological spectrum and review. J Clin Diagn Res. 2021;15(7):ED01–ED04.
6. Panda S, et al. Unusual presentations of rhinosporidiosis: a recent update. Indian J Dermatol. 2022;67(3):256–260.
7. Singh A, et al. Osseous rhinosporidiosis mimicking malignancy: case report and review. Cureus. 2023;15(2):e35123.
8. Kumar P, et al. Disseminated rhinosporidiosis involving bone: diagnostic challenges. J Orthop Case Rep. 2020;10(5):20–23.
9. Sharma S, et al. Disseminated rhinosporidiosis with atypical skeletal involvement: a diagnostic challenge. Cureus. 2022;14(5):e24876.
10. Ramesh V, et al. Bone rhinosporidiosis mimicking primary malignancy: a rare case report with review of literature. J Orthop Case Rep. 2021;11(6):45–48.
Downloads
Published
Issue
Section
License
Copyright (c) 2026 Kirthi Nath K V, Nivedha G

This work is licensed under a Creative Commons Attribution 4.0 International License.
Authors who publish with this journal agree to the following terms:
- Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons Attribution License that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.
- Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.
- Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) prior to and during the submission process, as it can lead to productive exchanges, as well as earlier and greater citation of published work (See The Effect of Open Access at http://opcit.eprints.org/oacitation-biblio.html).

