Nasal cavity, paranasal sinuses, nasopharynx
Infectious lesions

Topic Completed: 1 November 2004

Minor changes: 2 March 2020

Copyright: 2004-2020,, Inc.

PubMed Search: Rhinosporidiosis[TI] nasal[TIAB]

Nat Pernick, M.D.
Page views in 2019: 7,300
Page views in 2020 to date: 3,881
Cite this page: Pernick N. Rhinosporidiosis. website. Accessed August 12th, 2020.
Definition / general
Risk factors
Case reports
  • Surgical excision, may recur
  • No effective medical treatment
Gross description
  • Hyperplastic, polypoid, red, granular masses of nasal cavity
  • Yellow pinhead spots represent mature sporangia
  • Superficial mucus is common
Microscopic (histologic) description
  • Large (100 - 450 microns), thick walled sporangia with 1000+ endospores, each 6 - 10 microns, accompanied by a mixed inflammatory infiltrate
  • May not be present in all sections and may need additional sampling for diagnosis
Microscopic (histologic) images

Case of the Week #97:

Various images

Contributed by Prof. Venna Maheshwar,
Drs. Kiran Alam and Anshu Jain, JN Medical College, India:

Various images

Contributed by Dr. Alia Albawardi, Tawam Hospital (United Arab Emirates):

28 year old from Nepal with uvular mass; left to right: H&E (4 images), GMS, PAS

Positive stains
Differential diagnosis
  • Coccidiodes immitis: smaller spherules (30 - 60 microns), smaller endospores (2 - 5 microns)
  • Myospherulosis: large tissue spaces with saclike structures containing brown spherules that resemble Prototheca but are actually clumped red blood cells, GMS-
  • Often arthroconidia and hyphae
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