Nasal cavity, paranasal sinuses, nasopharynx
Inflammatory / infectious lesions

Author: Nat Pernick, M.D. (see Authors page)

Revised: 18 May 2018, last major update November 2004

Copyright: (c) 2004-2018,, Inc.

PubMed Search: Rhinosporidiosis[TI] nasal[TIAB]

Cite this page: Pernick, N. Rhinosporidiosis. website. Accessed October 17th, 2018.
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

Images hosted on PathOut server:

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