Introduction
Rhinosporidiosis is a chronic, granulomatous infection caused by Rhinosporidium seeberi. It is characterised by the development of granular, polypoidal masses primarily affecting the mucous membranes of the nasal cavity and nasopharynx. The disease is more common in South India and Sri Lanka.Reference Kumari, Nath, Rajalakshmi, Adityan and Thappa1 Cutaneous, laryngotracheal, genital and bony dissemination are rare, and can mimic soft tissue sarcoma.Reference Kumari, Nath, Rajalakshmi, Adityan and Thappa1–Reference Rekha, Thomas, Pappachan, Venugopal, Jayakumar and Sukumaran3 Following the onset of nasal lesions, it usually takes many years for systemic dissemination to occur.Reference Kumari, Nath, Rajalakshmi, Adityan and Thappa1
We report an extremely rare case of rhinosporidiosis with involvement of the larynx and trachea, together with coexisting nasal, nasopharyngeal and oropharyngeal lesions.
Case report
A 32-year-old man from an urban region of South India presented complaining of masses in both nostrils for four years, associated with progressive hoarseness of voice for one year. There had been many episodes of bleeding from the nasal masses. One year previously, the patient had noticed the gradual onset of progressive voice change, with blood-stained sputum on coughing. The patient had undergone three surgical procedures for the nasal and nasopharyngeal lesions. The most recent procedure had been one and a half years ago; six months later, the patient had again begun to develop throat symptoms. The patient had never bathed in ponds, and nobody from his neighbourhood had suffered similar illness.
Nasal cavity examination revealed reddish, strawberry-like, nodular, irregularly surfaced lesions studded with whitish specs on the mucosa of both nasal cavities, including both vestibules (Figure 1), and extending to the nasopharynx and oropharynx (Figure 2).
Fig. 1 Clinical photograph showing reddish rhinosporidial mass involving the left nasal cavity up to the vestibule.
Fig. 2 Clinical photograph showing reddish, strawberry-like rhinosporidial masses in the oropharynx, hanging down from the nasopharynx behind the uvula.
Tele-laryngoscopy showed multiple, sessile, reddish, nodular, strawberry-like masses with whitish specs on their surface, involving the laryngeal inlet and extending to the subglottis (Figure 3). Fibre-optic laryngoscopic examination revealed multiple sessile lesions occluding the tracheal lumen, more on the right lateral wall than the left.
Fig. 3 Tele-laryngoscopic view showing reddish, strawberry-like rhinosporidial mass with whitish spots on its surface, in the laryngeal inlet and involving the glottis and subglottis.
Computed tomography (CT) revealed soft tissue opacities involving both nasal cavities and the nasopharynx (Figure 4) and extending to the oropharynx, with involvement of the larynx and trachea (Figure 5).
Fig. 4 Coronal computed tomography scan showing soft tissue opacities involving both nasal cavities and the nasopharynx. R = right; L = left
Fig. 5 Axial computed tomography scan showing a soft tissue mass lesion involving the right lateral tracheal wall and partially occluding the tracheal lumen. L = left
Routine haematological investigations, chest radiography and fundoscopy were all normal. The patient was seronegative for human immunodeficiency virus.
A clinical diagnosis of laryngotracheal rhinosporidiosis was made. Diode laser excision of lesions was performed under direct laryngoscopy and rigid bronchoscopy guidance.
Histopathological examination of the excised specimens revealed hyperplastic epithelium with globular cysts of various shapes, representing sporangia at various stages of development (Figure 6).
Fig. 6 Photomicrograph of the excised specimen, showing hyperplastic epithelium with globular cysts of various shapes, representing sporangia at various stages of development. (Eosin & Hematoxylin stain, 40 ×Magnification)
Post-operatively, the patient was commenced on dapsone 100 mg/day, which he was advised to continue for two years.
Discussion
Rhinosporidiosis was first reported in Eastern India in 1894, by O'Kinealy.Reference Raveenthiran4 The disease is caused by Rhinosporidium seeberi, a protist belonging to the mesomycetozoea family of aquatic parasites.Reference Kumari, Nath, Rajalakshmi, Adityan and Thappa1, Reference Arseculeratne5 In 1923, Ashworth named the organism Rhinosporidium seeberi, after Guillermo Seeber, who submitted a doctoral thesis on the topic in 1900.Reference Raveenthiran4
Although rhinosporidiosis has been reported in the Americas, Europe, Africa and Asia, it is far more common in the tropics, with greatest prevalence seen in South India and Sri Lanka.Reference Kumari, Nath, Rajalakshmi, Adityan and Thappa1, Reference Pang, Wu, Lupi and Tyring6, Reference Kumar, Mathew, Cherian, Rozario and Kurien7 It may be transmitted by direct contact with the spores of R seeberi via dust or infected clothing, or through swimming in stagnant water contaminated with the spores. The organism has developed various mechanisms of immune evasion (i.e. immune deviation, suppression of local immune responses, immunoglobulin binding and antigenic variation), making both humoral and cell-mediated immunity less effective against the infection.Reference Arseculeratne5
Nasopharyngeal lesions are seen predominantly in males, while ocular infection is more prevalent among females.Reference Kumari, Nath, Rajalakshmi, Adityan and Thappa1 Infection produces granulomatous inflammation of the affected tissues. In the nose, infection produces painless mucosal papules that evolve into large and hyperplastic polypoidal masses which characteristically bleed on touch and have a raspberry-coloured background with white specs (representing the chitinous walls of rhinosporidial sporangia).Reference Kumari, Nath, Rajalakshmi, Adityan and Thappa1, Reference Pang, Wu, Lupi and Tyring6 Masses are usually unilateral and pedunculated, and rarely exteriorise. Other mucosal sites are involved infrequently, including the palpebral conjunctiva, oropharynx, nasopharynx, maxillary antrum, larynx, external ear canal, parotid duct and genitalia.Reference Rekha, Thomas, Pappachan, Venugopal, Jayakumar and Sukumaran3, Reference Pang, Wu, Lupi and Tyring6, Reference Kumar, Mathew, Cherian, Rozario and Kurien7 Oral and oropharyngeal lesions may interfere with breathing and/or eating.Reference Pang, Wu, Lupi and Tyring6
Systemic dissemination to the trachea, lung, urethra, liver, genitalia, lacrimal sac and bone is very rare.Reference Kumari, Nath, Rajalakshmi, Adityan and Thappa1, Reference Rekha, Thomas, Pappachan, Venugopal, Jayakumar and Sukumaran3, Reference Pang, Wu, Lupi and Tyring6 Dissemination can be fatal, and occurs more commonly in association with immunodeficiency disorders (such as acquired immunodeficiency syndrome). Infection can spread via body fluids such as ascites and blood. Airway obstruction, profuse bleeding and multiorgan failure often precipitate death.Reference Raveenthiran4 In our patient, laryngotracheal dissemination could have been due to implantation of spores into the laryngeal and tracheal mucosa during episodes of recurrent bleeding from nasopharyngeal lesions and during previous surgery. Biopsy of such lesions must be avoided due to the risk of bleeding and aspiration, which may prove fatal. Computed tomography of the neck and thorax is preferred in these situations to evaluate the extent of laryngotracheal lesions.
Diagnosis is confirmed on the basis of histopathological demonstration of the characteristic thick-walled giant sporangia (measuring 60–450 µm or more in diameter) in various stages of development and containing sporangiospores (7–15 µm in diameter, and up to 12 000 in number).Reference Kumari, Nath, Rajalakshmi, Adityan and Thappa1, Reference Pang, Wu, Lupi and Tyring6, Reference Kumar, Mathew, Cherian, Rozario and Kurien7Rhinosporidium seeberi is easily identified in haematoxylin and eosin stained smears. Spores and sporangia are better demonstrated by periodic acid Schiff, Mayer's mucicarmine, Verhoff's vonGieson and Grocott Gomori methamine silver stains.Reference Loh, Chong, Pang and Soh8, Reference Nath, Madana, Yolmo and D'Souza9
Barring one report by Levy et al., cultivation has not been successful.
Recently, tests for assessing the viability of the organism have been developed. Spherical bodies, provisionally regarded as the electron-dense bodies of endospores, are able to reduce the salt 3-[4,5-dimethyl-2-thiazolyl]-2,5-diphenyl-2H-tetrazolium bromide to a formazan that can be visualised microscopically.Reference Arseculeratne5, Reference Nath, Madana, Yolmo and D'Souza9
Surgical extirpation is the treatment of choice. Following surgical excision, cauterisation or ablation of the lesion base is strongly recommended, as local recurrences are common due spillage of sporangia.Reference Kumari, Nath, Rajalakshmi, Adityan and Thappa1 Rigid bronchoscopy combined with tracheotomy is useful in the removal of laryngotracheal lesions. The likelihood of bleeding from these lesions makes surgical intervention difficult.Reference Rekha, Thomas, Pappachan, Venugopal, Jayakumar and Sukumaran3 In our patient, direct laryngoscopy and rigid bronchoscopy guided excision of the laryngeal and tracheal lesions was performed without tracheostomy. No rhinosporidial lesions were seen in either main bronchus.
• Rhinosporidiosis is a chronic, granulomatous disease that usually affects the mucous membranes of the nose and nasopharynx
• Lower dissemination into the trachea is extremely rare
• Laryngotracheal involvement poses many diagnostic and therapeutic challenges, due to the potential risk of bleeding and aspiration
• In the presented case, laryngotracheal involvement may have been due to local spread with direct spillage of spores from the nasopharynx into the larynx during episodes of bleeding or previous surgery, although systemic spread cannot be excluded
Nasal lesions recur following surgery in approximately 10 per cent of cases; the incidence of recurrence of laryngotracheal lesions is not known due to their extreme rarity.Reference Rekha, Thomas, Pappachan, Venugopal, Jayakumar and Sukumaran3, Reference Pillai10
Medical treatment of rhinosporidiosis with dapsone may be effective, as it arrests the maturation of sporangia, accelerates their degeneration, increases the granulomatous response with fibrosis, and prevents recurrence by interfering with the folic acid metabolism of the organism.Reference Kumari, Nath, Rajalakshmi, Adityan and Thappa1, Reference Raveenthiran4, Reference Kumar, Mathew, Cherian, Rozario and Kurien7, Reference Pillai10
