Rhinoentomophthoromycosis Caused by Conidiobolous Coronatus in a Diabetic Patient: the Importance of Species Identification
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Rhinoentomophthoromycosis caused by Conidiobolous coronatus in a diabetic patient: the importance of species identification Anil Kumar, Vineeth Viswam1, Sukhmani Regi2, Kavitha R. Dinesh, Madhumita Kumar1, Shamsul Karim Departments of Microbiology, 1Otorhinolaryngology, and 2Pathology, Amrita Institute of Medical Sciences, Ponekara, Kochi, Kerala, India CASE REPORT CASE Abstract by swelling of nose, paranasal sinuses, and mouth. We present a case of a 43-year-old male who presented with rightRhinoentomopthoromycosis nasal blockade and paranasal usually sinus presents pain assince a chronic two months. inflammatory The clinical or granulomatous picture was further disease complicated characterized by the fact that neither the patient could tolerate plain amphoterecin B nor could he afford its liposomal derivative. appropriateSpecies identification choice of therapyenabled in us resource to successfully poor settings treat the in developing patient with countries. cheaper and less toxic alternative like itraconazole and potassium iodide. Our case highlights the importance of species identification in making Key words: Conidiobolus coronatus, potassium iodide, Splendore-Hoeppli phenomenon Introduction tomography (CT) of paranasal sinuses revealed a retention cyst in the right maxillary sinus and Entomophthoromycosis (Conidiobolomycosis) is caused a soft tissue mass measuring 5.6 cm × 1.5 cm in by Conidiobolus coronatus, a mould belonging to the the right nasal cavity extending from anterior nare order Entomopthorales of the class Zygomycetes. The up to midpoint of nasal cavity [Figure 1]. The nasal fungus thrives as a saprophyte in soil and in decomposed septum was deformed in an “S” shaped curve. plant detritus in moist and warm climate.[1] Infection is Functional endoscopic sinus surgery revealed a caused either by introduction into the nasal cavity by polypoidal growth in the right middle meatus and soiled hands or through inhalation of spores involving subcutaneous tissue with a protracted and chronic clinical maxillary antrum that were excised and sent for evolution responding very well to antifungal therapy.[2,3] culture and histopathology. Histological sections on We present one such case of entomophthoromycosis hematoxylin and eosin staining [Figure 2] showed caused by C. coronatus, in a diabetic patient where multiple broad thin walled aseptate hyphae with non- species identification helped us successfully treat the parallel sides and right angled branching surrounded patient with cheap and less toxic drugs like itraconazole and potassium iodide. Case Report A 43-year-old diabetic male on insulin therapy was admitted in our hospital for further evaluation and treatment of right nasal mass. Plain computerized Access this article online Quick Response Code: Website: www.atmph.org DOI: 10.4103/1755-6783.120999 Figure 1: Plain computerized tomography of paranasal sinuses a soft tissue mass measuring 5.6 cm × 1.5 cm in the right nasal cavity Correspondence: Dr. V. Anil Kumar, Department of Microbiology, Amrita Institute of Medical Sciences, Ponekkara, Kochi, Kerala, India. E-mail: [email protected] Annals of Tropical Medicine and Public Health | May-Jun 2013 | Vol 6 | Issue 3 331 Kumar, et al.: Rhinoentomophthoromycosis due to Conidiobolous coronatus by eosinophilic granuloma (Splendore-Hoeppli papilla [Figure 5]. Few conidia also produced hair-like phenomenon) suggestive of entomophthoromycosis. appendages, called villae [Figure 6] and some germinate Since the patient expressed his inability to afford to produce multiple hyphal tubes [Figure 7]. Based liposomal amphoterecin B (AMB) he was started on the macro- and micromorphological criteria, the on plain AMB, which he could not tolerate and was isolate was identified as Conidiobolus coronatus. On discontinued after the first dose. Further treatment his follow-up visit the patient had come prepared to sell was deferred pending culture report and patient his property to buy liposomal AMB. Since the isolate was advised to make necessary arrangements was identified as C. coronatus we decided to treat the to buy liposomal AMB on follow up. Cultures patient with alternative regimen without AMB. The on Sabourauds dextrose agar with and without patient was given a loading dose of itraconazole 200 antibiotics at 37°C grew a Zygomycete within 72 mg thrice daily for 5 days followed by 200 mg twice hours of incubation. Colonies were flat cream colored daily along with potassium iodide tend drops thrice and glabrous covered by fine powdery white surface daily in a concentration of 1 gm/ml (i.e., one drop mycelium [Figure 3]. The inside of the lid of the Petri = 67 mg) diluted in milk or fruit juice. During the dish soon became covered with conidia, which are entire course of the treatment thyroid function, liver forcibly discharged by the conidiophores [Figure 4] function, and serum potassium levels were regularly that is classical of Entomopthorales (Conidiobolus monitored. The patient was cured completely after and Basidiobolus). Conidia were spherical, 10-25 four months of therapy. A repeat endoscopy and CT µm in diameter, single-celled and had a prominent scan done at fourth month revealed clear sinuses. Figure 2: Tissue sections on hematoxylin and eosin staining Figure 3: Flat cream colored and glabrous colonies covered by fine showed multiple broad hyphae with non-parallel sides surrounded by powdery white surface mycelium eosinophilic granuloma (Splendore-Hoeppli phenomenon) (×1000) Figure 4: Lid of the Petri dish covered with conidia, which are forcibly Figure 5: Spherical single-celled conidia with a prominent papilla discharged by the conidiophores (×1000) 332 Annals of Tropical Medicine and Public Health | May-Jun 2013 | Vol 6 | Issue 3 Kumar, et al.: Rhinoentomophthoromycosis due to Conidiobolous coronatus Figure 6: Typical conidia of Conidiobolous coronatus producing hair- Figure 7: Conidia germinate to produce either multiple hyphal tubes like appendages, called villae (×1000) that may also become conidiophores, which bear secondary conidia (×1000) Discussion sinuses which if left untreated spreads to skin and soft tissue of the face causing severe disfigurement (like Entomophthoromycosis is a rare subcutaneous that of hippopotamus).[13] Entomophthoromycosis is infection manifesting either as a painless nodule on most often diagnosed by histological demonstration of the trunk or as rhinofacial zygomycosis involving the thin walled broad aseptate hyphae with an eosinophilic nasal cavity, paranasal sinuses, and the soft tissue precipitate around the fungi referred as Splendore- of the face.[4] The disease is largely restricted to the Hoeppli phenomenon resulting from host immune tropical regions of Africa, Asia, and South America. response. Splendore-Hoeppli phenomenon is typically Infections due to Zygomycete fungi of the Mucorales seen in all cases of entomophthoromycosis but not in order occur in immunocompromised individuals or mucormycosis.[12] Fungal hyphae of Conidiobolus spp. patients with poorly controlled diabetes mellitus.[2,3] can masquerade as both Mucorales and Aspergillus spp. These characteristically are angioinvasive, with a in tissue sections in the absence of Splendore-Hoeppli tendency to disseminate, and have a rapid and often phenomenon in immunocompromised patients.[12] fatal clinical course. Conversely, diseases caused Thus, histological features must be interpreted with by Zygomycetes of the Entomophthorales order caution and species identification by culture should be (Conidiobolus and Basidiobolus) most commonly used to decide antifungal therapy. present in immunocompetent hosts, predominantly involve subcutaneous tissue, are not angioinvasive, Treatment of Entomophthoromycosis is difficult have a protracted and chronic clinical evolution and and general recommendations are lacking. Surgical respond well to antifungal therapy.[5,6] Conidiobolus is a resection is controversial as it may hasten the spread of mould found in soil and decaying plant debris.[1] It is also infection. Systemic antifungal therapies with a varying isolated from insects and amphibians.[7] Conidiobolus combination of potassium iodide, imidazoles, AMB, spp. are the causative agents of infections in humans, terbinafine, hyperbaric oxygen, and co-trimoxazole sheep, dogs, deer, and horses.[8] The genus contains 27 have all been used with varying success.[14] Recent species; however, C. coronatus, C. incongruous, and C. reports have shown that patients respond well to azole lamprauges are the only species that are known to cause group of antifungals like itraconazole (200-400 mg/day), human disease.[7,9,10] The colony morphology is similar fluconazole (100-200 mg/day), and ketoconazole (200- but microscopically the C. coronatus produce villose 400 mg/day).[15] Of these itraconazole and fluconazole conidium and secondary conidia in addition to beaked are both effective and relatively safe.[16] The low cost conidia whereas C. incongruus produce only beaked and ease of administration of potassium iodide make conidia and yellow zygospores.[11] The presence of a it very useful for patient in developing countries. single large globule within a mature zygospore serves Combinations of oral azoles with potassium iodide as a presumptive identification for C. lamprauges.[12] have shown to give rapid and lasting results.[17,18] C. coronatus is the most frequently isolated species from clinical specimens and rarely do they cause Our case report underlines the relevance of disseminated