Rhinosporidiosis of Parotid Duct Presenting as Consecutive Bilateral Facial Swelling: A Rare Case Report and Literature Review

Abstract

Rhinosporidiosis is a chronic granulomatous infection caused by Rhinosporidium seeberi. Sporadic cases of rhinosporidiosis has been reported from many countries but is endemic in Southern India (Madurai, Ramnad, Rajapalayam and Sivaganga), Nepal, Bangladesh and Sri Lanka. This disease commonly affects the mucous membrane of the nose or naso-pharynx and presents as a leafy, polypoidal mass. The reported extranasal sites include the oro-pharynx, eye, ear, larynx, trachea, bronchi, skin and genital mucosa. It may also become disseminated to present as a generalized form. In our case a 40-year-old female from rural West Bengal (Eastern India) presented with right sided facial swelling. Our provisional diagnosis was parotid duct cyst on the basis of careful history, scrupulous clinical examination and relevant investigations comprising CECT scan of face. Although Rhinosporidiosis was not taken into consideration in the clinical differential diagnosis, it was eventually diagnosed postoperatively by histopathological examination of surgical specimen. Two months later in follow-up, the same patient presented to us with left sided facial swelling. We managed the left facial swelling successfully with minimally invasive surgery and 100mg twice daily dapsone for 6 months. We present this case firstly because Rhinosporidiosis of parotid duct (stensen's duct) is a rare entity and secondly non-neoplastic cysts of the salivary glands are also uncommon and represent only 2-5% of all salivary gland lesions. Furthermore our case emphasizes that the clinicians should aware of this rare clinical entity specially in endemic areas, because minimally invasive techniques and medications might solve the problem while helping patients to avoid surgical excision.

Keywords: Dapsone; Mesomycetozoea; Minimally invasive surgery; Stensen’s duct cyst.

[Table/Fig-1]:

(a) Front view of the patient showing right sided facial swelling (b) the swelling was brilliantly transilluminant (c) CECT of the face showing a thick-walled peripherally enhancing cystic lesion overlying right masseter muscle (d) Intraoperative picture during excision of cyst(parotid duct hooked by a artery forcep).

[Table/Fig-2]:

(a) Sporangia containing numerous daughter spores (H&E stain, X 100) (b) Lining of the parotid duct showing heavy inflammatory reaction with spores of Rhinosporidiosis (H&E stain, X 40).

[Table/Fig-3]:

(a) Front view of the same patient showing left sided facial swelling .(b)Intraoral picture showing stensen’s duct stent in-situ(white vertical arrow).(c) Recent photograph of the patient after 12 months follow-up.