Rhinosporidiosis- Surgical treatment
Rhinosporidiosis is an infectious disease caused by Rhinosporidium seeberi
It is a chronic disease, with frequent recurrence after surgery, and occasional dissemination from the initial focus which is most commonly seen in upper respiratory tract. It occurs universally, although it is endemic in south Asia, notably southern India and in Sri Lanka.
It has also to be explained why the disease is of high endemicity in certain regions of southern India and in the dry zone of Sri Lanka. If indeed stagnant ground waters are the natural habitat, then the chemical and physical characteristics of these waters need definition.
The great majority of cases occur in upper respiratory sites, notably the anterior nares, the nasal cavity – the inferior turbinates, septum and floor. Posteriorly, rhinosporidial polyps occur in the nasopharynx, larynx, and soft palate; the buccal cavity is only rarely affected. The disease, while being of special interest to oto-rhinolaryngologists, is of interest to dermatologists and ophthalmologists as well, through the occurrence of granulomas in the skin, subcutaneous tissues and eye. About 15% of cases of rhinosporidiosis are ocular in location, in the bulbar and palpebral conjunctiva.
Rhinosporidiosis of the lacrimal sac and naso-lacrimal duct has been documented and it has been suggested that the primary site of rhinosporidiosis is the lacrimal sac with downward spread to the nasal passages through the naso-lacrimal duct; this view is untenable since nasal rhinosporidiosis has occurred as the primary lesion while in other cases a concomitant infection of the lacrimal apparatus has been on the contra lateral side.
Characteristically, rhinosporidial lesions in the nasal passages are polypoidal, granular, red in color due to pronounced vascularity; with a surface containing yellowish pin head-sized spots which represent underlying mature sporangia. A covering of mucoid secretions is not uncommon. Naso-pharyngeal polyps are often multi-lobed with a variegated appearance, with typical strawberry like regions and other areas which have relatively less vascular lobes with smooth surfaces.
Histopathology-The stroma which is either fibro-myxomatous or fibrous contains chronic inflammatory cells which include macrophages and lymphocytes, while neutrophils are numerous around free endospores. In granulomatous tissue, giant cells occur often within sporangia and in the stroma. Fibrosis is prominent, notably, in non-respiratory sites. A noteworthy feature is the variability of stromal and cellular reactions even within tissues from a single patient.
The definitive diagnosis of rhinosporidiosis is by histopathology on biopsied or resected tissues, with the identification of the pathogen in its diverse stages, rather than the stromal and cellular responses of the host.
Although cases of spontaneous regression have been recorded, they are rare, and the mode of treatment remains surgical. Total excision of the polyp, preferably by electro-cautery, is recommended. Pedunculated polyps permit of radical removal while excision of sessile polyps with broad bases of attachment to the underlying tissues are sometimes followed by recurrence due to spillage of endospores on the adjacent mucosa. Extensive growths, as on the penis, might require amputation of the affected site.
While several anti-bacterial and anti-fungal drugs have been tested clinically, but unsuccessfully, the only drug which was found to have some anti-rhinosporidial effect is dapsone (4,4-diaminodiphenyl sulphone) which appears to arrest the maturation of the sporangia and to promote fibrosis in the stroma, when used as an adjunct to surgery.
There have been no innovations in treatment since surgery and dapsone were introduced.
Dose of Dapsone- 100 mg once daily for 2-3 months.Check LFT and blood counts every 2 weeks.
Laser Surgical removal
Smaller lesions can easily be removed by Co2 laser with minimal bleeding. But Larger polyps are difficult to remove and the theoretical hazard of spreading spores in the plume and need for fumigation of the theatre afterwards.