Fig. 6.67 A, B. Rhinosporidiosis commonly presents with nasal polyps. A The cut section of a nasal polyp in which there is squamous metaplasia of the epithelium. There are numerous spherical strictures within the thorium and outside the mucosa. H & E, x40. Eventually a granulomatous reaction occurs and B mature spherules discharge the endospores through the lining epithelium. H & E, x 160. (A, B from Bittencourt and Londero 1995)

Fig. 6.68. A A nasal polyp with tiny white spots in an 11-year-old child. B A conjunctival lesion. In India about 90% of patients have nasal polyps whereas in Brazil more than half have conjunctival lesions, and this is the pattern in Africa. (A courtesy of Dr. I. Campbell, Brazil; B courtesy of Prof. R. Marback, Brazil; both from Bittencourt and Londero 1995)

Clinical Characteristics

Rhinosporidiosis in children is equally common in males and females, but in adolescents and adults it is much more common in males: this probably reflects an occupational association. Wherever the infection occurs, it appears clinically as soft, friable, vascular polyps, from pink to red to violet in color. On the skin, early lesions are flat. The polyps are lobulated and bleed easily. Under the epithelium there are tiny white spots, which are the sporangia. On the skin the papillomatous lesions may become warty. The infection may persist for 30 years or more, yet dissemination is uncommon. New lesions are usually clost to the original sites, and auto-inoculation is suspected. The polyps may become significantly pedunculated and when in the nose they may block the ostia into the sinuses: on the conjunctiva they can be large enough to evert the lid.

Two-thirds of the reported infections are in the nose, and present clinically as nasal obstruction or bleeding. They are not painful, but may cause irritation. As they grow, there is a profuse mucoid nasal discharge. Pedunculated polyps may extend backwards into the pharyn and spread onto the palate. However, the most common site is anteriorly in the nose, particularly along the septum.

As noted, the palpebral conjunctiva is the next most common site (Fig. 6.68 B). The patient may complain of a foreign body in the eye or of a blood stained discharge. This is worsened if the lacrimal ducts are occluded.

Similar lesions in the larynx cause hoarseness: on the tongue and palate a common presentation is a sessile granuloma.

In the urethra, rhinosporidiosis is much more common in men than in women. A similar friable, pink discrete painless polyp protrudes from the urethral meatus. Multiple lesions in the urethra have presented further posteriorly. Hematuria, intermittent bleeding, and discharge are the reasons that the patients come for treatment. Similar polypoid or flat lesions occur in the vagina, vulva, or rectum, but,
as noted already, sexual transmission has not been recorded.

Spread to the liver, spleen, lungs, and kidneys is excessively rare. There is likely to be ascites and in some patients, peripheral edema. Osseous lesions have been identified in only two patients: one with a granuloma in the scapula and another with osteolytic foci in the hands and feet.

If there are systemic clinical symptoms in a patient with rhinosporidiosis, it should suggest an accompanying pyogenic infection. Only in the very rare, widely disseminated infection is there likely to be fever, wasting, and perhaps, death.

Imaging Diagnosis

The soft tissue masses do not require imaging. Blockage of the paranasal sinuses or in the nasopharynx can be demonstrated and in very longstanding infections there may be deformity of the facial bones. In a few patients, the polypoid masses in the trachea or bronchi have caused mild obstruction with air trapping.

There are no specific imaging findings: rhinosporidiosis is another cause of an opaque antrum or other sinus, of a mass in the airways, and occasionally of pulmonary atelectasis. The bone changes are nonspecific: the urethral polyps are more likely to be of concern to patients than to require imaging.

Acknowledgements. We are grateful to Dr. Demosthenes Pappagianis, MD, PhD, Professor of Medical Microbiology and Director of the Coccidioidomycosis Serology Laboratory, School of Medicine, University of California, Davis, Calif., USA, who was kind enough to advise us on the many details of mycology in this chapter.