RHINOSPORIDIOSIS

RHINOSPORIDIOSIS
  • Rhinosporidiosis is a chronic zoonotic infection caused by eukaryotic organism Rhinosporidium seeberi
  • It is endemic in Brazil, Sri Lanka and India. Sporadic cases are seen in USA
  • Mode of transmission –
    • From the cattle, horses and mules
    • Endospores are transmitted by water or dust
    • They penetrate the nasal cavity mucosa and matures into sporangium within the submucosal tissue
    • After maturation sporangia bursts and releases endospores into surrounding tissue
  • Clinical features
    • Site – sinonasal tract (common). Other sites are Larynx, tracheobronchial tree, esophagus, conjunctiva, ears and genital tract
    • Age – usually in the 3rd and 4th decades of life but can occur at any age group
    • Sex –  slight male predominance
    • Symptoms – Patients present with 
      • Nasal obstruction
      • Rhinorrhea
      • Epistaxis
  •   Morphology
    • Gross – Presents as polypoidal mass which may be single or multiple, sessile or pedunculated typically described as strawberry like appearance
    • Microscopy
      • Polypoidal mucosal tissue lined by ciliated pseudostratified columnar epithelium or metaplastic stratified squamous epithelium
      • Characteristic sporangia of size 150 – 350μm are present in mucosa and submucosa
      • Mature spoprangia has thick chitinous wall and contains hundreds to thousands of endospores (2 – 9μm)
      • Immature endospores are presen at the periphery of the sporangia and the central part of sporangia has mature endospores
      • Edematous interstitial stroma contains chronic inflammatory cells containing lymphocytes, plasma cells and eosinophils
      • Neutrophilic infiltration and granuloma formation are seen when there is rupture of the sporangia
  • Treatment and prognosis
    • Surgical excision is the treatment of choice. Antibiotics are not effective
    • Prognosis is excellent
 
Rhinosporidiosis

Rhinosporidiosis: Mucosal tissue lined by metaplastic stratified squamous epithelium. Underlying edmatous troma shows sporangia with endospores and inflammtory cells (H&E,X50)

 

Rhinosporidiosis

Rhinosporidiosis: Mucosal tissue lined by metaplastic stratified squamous epithelium. Underlying edmatous troma shows sporangia with endospores and inflammtory cells (H&E,X100)

 

Rhinosporidiosis: Tissue lined by Stratified squamous epithelium. Underlying stroma shows mature sporangia with spores and immature sporangia. Interstitial stroma shows chronic inflammatory cell infiltrate, focal lymphoid aggregate and congested blood vessels (H&E,X100)


Rhinosporidiosis: Tissue lined by Stratified squamous epithelium. Underlying stroma shows immature sporangia. Interstitial stroma shows chronic inflammatory cell infiltrate and granulomas with giant cells (H&E,X100)

Rhinosporidiosis: Tissue lined by stratified squamous epithelium. underlying stroma shows mature and immature sporangia (H&E,X100)

Rhinosporidiosis: Tissue lined by stratified squamous epithelium (right). underlying stroma shows immature sporangia and chronic inflammatory cells (H&E,X100)


Rhinosporidiosis

Rhinosporidiosis: Mature sporangia (Usually m/s 150 – 350 µm) with central mature endospores and peripheral small immature endospores (2 -9µm) (H&E,X400)



Rhinosporidiosis: Mature sporangia (Usually m/s 150 – 350 µm) with central mature endospores and peripheral small immature endospores (2 -9µm) (H&E,X400)


Rhinosporidiosis: Mature sporangia (Usually m/s 150 – 350 µ) with central mature endospores and peripheral small immature endospores (2 -9µm) (H&E,X400)