|Year : 2017 | Volume
| Issue : 3 | Page : 157-159
Multiple eumycetomas caused by Pyrenochaeta romeroi in a renal allograft recipient
Gwendolyn Fernandes, Dimpi Ohri, Deepa Nebhnani
Department of Pathology, Seth G. S. Medical College and K.E.M. Hospital, Mumbai, Maharashtra, India
|Date of Web Publication||20-Dec-2017|
Dr. Gwendolyn Fernandes
C-802, Swayam, Poonam Gardens, Opp. S.K. Stone, Off Mira.Bhayander Highway, Mira Road. (E), Thane - 401 107, Maharashtra
Source of Support: None, Conflict of Interest: None
The incidence of unusual fungal infections in renal allografts has been rising in the last few years. We report an unusual case of eumycotic mycetomas at multiple sites caused by a fungus Pyrenochaeta romeroi, in a 43-year-old male, farmer by occupation and renal allograft recipient. The patient had undergone a live, related donor transplant 9 months earlier, with wife as donor, and was on tacrolimus, mycophenolate mofetil and steroids. This is the only case of P. romeroi causing nodular eumycetomas at multiple sites in a renal allograft recipient. All case reports have reported single lesion and multiple lesions are uncommon.
Keywords: Eumycetoma, Pyrenochaeta romeroi, renal allograft
|How to cite this article:|
Fernandes G, Ohri D, Nebhnani D. Multiple eumycetomas caused by Pyrenochaeta romeroi in a renal allograft recipient. Indian J Transplant 2017;11:157-9
|How to cite this URL:|
Fernandes G, Ohri D, Nebhnani D. Multiple eumycetomas caused by Pyrenochaeta romeroi in a renal allograft recipient. Indian J Transplant [serial online] 2017 [cited 2020 Sep 28];11:157-9. Available from: http://www.ijtonline.in/text.asp?2017/11/3/157/221185
| Introduction|| |
Candida and Aspergillus are the most common opportunistic fungal infections in renal transplant recipients. We report an unusual case of eumycotic mycetomas (EMs) at multiple sites caused by a fungus Pyrenochaeta romeroi, in a 43-year-old male, farmer by occupation. He was a renal allograft recipient for the past 9 months with the wife as the donor and was on maintenance immunosuppression.
EMs are caused by true fungi, which cause chronic suppurative granulomatous disease usually involving the skin and subcutaneous tissue. The infection is characterized by tumefaction and multiple sinuses which show the characteristic “grains” composed of fungal colonies.
| Case Report|| |
A 43-year-old male, farmer by occupation and renal allograft recipient (live related donor) from Madhya Pradesh, presented 9-month posttransplant, with multiple painless nodular lesions over left thigh, left calf, right shin, and right second toe [Figure 1]a and [Figure 1]b. The lesions were 1-2 cm in size, soft to firm, non-ulcerated, and mildly tender. There was no history of trauma, fever, or lymphadenopathy. Donor and recipient pretransplant cytomegalovirus (CMV) tests were negative. He had posttransplant diabetes and the serological tests for HIV, hepatitis B virus, hepatitis C virus, and CMV were negative. Other laboratory investigations were within normal range except for a relative neutrophilic leukocytosis. Renal function tests were normal. Radiological examination of all the sites was done and there was no underlying osteomyelitis.
|Figure 1: (a) Lesion on the thigh showing pustule formation and surface ulceration. (b) 1 cm × 1 cm nodular lesion on the toe|
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He was given a 250 mg cumulative dose of antithymocyte globulin during induction as his weight was 46 kg and triple drug maintenance immunosuppression with tacrolimus, mycophenolate mofetil and steroids. The graft function was stable and there was no evidence of any other infection till the development of these lesions.
Fine-needle aspiration cytology (FNAC) of the left thigh and right second toe swellings were carried out by standard aspiration techniques. Pus was aspirated and the smears stained by the routine Papanicolaou and Giemsa stains. Smears revealed abundant multinucleated giant cells (MGCs), few with intracellular organisms, dense neutrophilic infiltrate, macrophages, and entangled hyphal clusters on a background of necrotic material. A diagnosis of inflammatory pathology, suggestive of fungal abscess was made on the FNAC aspirates. A sample of aspirate was sent for microbiologic examination.
The left thigh lesion was biopsied. Histopathological examination showed a florid granulomatous reaction with abundant MGCs, macrophages, lymphocytes, and neutrophils. Few pigmented hyphae, approximately 3 μ thick were seen with brownish pigment in their cell walls. The hyphae were also seen within the cytoplasm of MGCs. Gomori methenamine silver and periodic acid–Schiff stains showed abundant, broad, branching, and septate hyphae. Granulomatous inflammation, due to pigmented fungal etiology was reported. Fungal cultures were advised for exact typing of the fungus.
Potassium hydroxide examination of the aspirates revealed septate dark fungal hyphae. The aspirate from the lesions was inoculated on Sabouraud's dextrose agar slants, and the fungus grew as a dark gray mycelial mat with aerial hyphae. Lactophenol cotton blue mount showed septate branched dark hyphae.
The exact species identification was carried out by DNA extraction and sequencing. The amplified ITS region of the strain was 578 bp in length (GenBank Accession Number JX 088727) and shared 99% identity with P. romeroi (GenBank DQ836803). The sequence of our isolate had a 1 nucleotide gap compared to P. romeroi isolates IP 888.65 (GenBank DQ836803), Kw596 (GenBank FN826905), and B36 (Genbank EF488398) and two nucleotide substitutions compared to P. romeroi isolates IP 571.61 (Genbank DQ836802) and IP 862.63 (Genbank DQ836801). Thus, the causative organism was identified as P. romeroi.
Before species identification, the patient was provisionally started on itraconazole 400mg daily and terbinafine 250 mg daily. The lesions increased in size. After the fungus was confirmed to be P. romeroi, the patient was put on voriconazole 200 mg twice daily and terbinafine 250 mg thrice daily was continued.
After 7 months, the lesions recurred at the same sites and enlarged in size. The left thigh lesion was completely excised and sent for histopathological examination. A piece of skin with an irregular gray-white tumefactive lesion, measuring 6 cm × 2 cm was received [Figure 2]a and [Figure 2]b. On cutting through, it showed sinuses with necrotic material. Microscopic examination revealed a foreign body of plant origin surrounded by a florid granulomatous reaction and fibrosis. Many MGCs with fungal elements were seen with morphological features similar to the fungus in the biopsy specimen [Figure 3]a, [Figure 3]b, [Figure 3]c, [Figure 3]d, [Figure 3]e, [Figure 3]f. The overlying skin was hyperplastic, ulcerated and showed sinus tracts extending to the subcutaneous tissue. The sinus tracts showed a lining of squamous epithelium, necrotic material, and masses of fungal hyphae. A final diagnosis of EM caused by P. romeroi, with an implanted plant-origin foreign body was made.
|Figure 2: (a) Excised lesion from left thigh showing tumefactive skin lesion with development of sinuses. (b) Sections through the lesion show sinuses filled with necrotic material|
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|Figure 3: (a) Sinus tract (H and E, ×100). (b) A foreign body of plant origin seen surrounded by inflammatory cells (H and E, ×400). (c) Florid granulomatous reaction with abundant multinucleated giant cells and inflammatory cells (H and E, ×400). (d) Brown pigmented fungal forms seen in the sinus tract (H and E, ×400). (e) A fungal colony composed of fungal hyphae seen in the excised thigh lesion (H and E, ×400). (f) Branching fungal hyphae (GMS, oil immersion)|
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Since the lesions recurred and did not heal, the dose of immunosuppressants was decreased. Tacrolimus dose which was 0.1 mg/kg/day in 2 divided doses was reduced to half, and the patient developed antibody mediated rejection as well as unstable angina and was put on dialysis. He was later lost to follow-up.
| Discussion|| |
Eumycetomas are caused by true fungi and are extremely rare infections in renal allograft patients. Similar cases of nodulo-cystic eumycetoma in a renal allograft recipient has been documented by Ocampo et al., Chan et al., Thiyagarajan et al.,, All cases described in literature show a single lesion unlike our case which showed multiple lesions, on the left thigh, the left calf, right shin, and right second toe. These organisms are soil saprophytes and shows geographic occurrence in Central and South America, Africa, and Asia.,, Our patient's farming occupation could have predisposed him to traumatic inoculation of spores on the extremities. The history of trauma may not be obtained.
The earliest sign of mycetomas is the development of painless subcutaneous nodules. As the lesion enlarges, papules and pustules appear which form discharging sinuses, which may dry up leaving scars. Our case followed a similar course.
The grains composed of fungal colonies can be of various colors and vary in size from microscopic (200 μ) to visible ones.
The genus Pyrenochaeta is included in the phylum Coelomycetes. The role of melanin found in pigmented fungi is not fully understood, although it has been linked to virulence and pathogenicity.
P. romeroi has been shown to be resistant to broad spectrum antifungals such as amphotericin B, itraconazole, and caspofungin. Khan et al. reported that P. romeroi is sensitive to voriconazole and posaconazole.
| Conclusion|| |
Although EMs are rare in renal transplant recipients, mycetomas can lead to serious complications such as deformities, fungal osteomyelitis, and the need for amputations. Awareness and a high index of suspicion are hereby advocated. Treatment is challenging and needs to be individualized with in vitro antifungal susceptibility tests. This is a rare case of eumycetomas at multiple sites caused by P. romeroi in a renal allograft recipient.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
We would like to thank Dr. Jacques Meis, Consultant Microbiologist, Department of Medical Microbiology and Infectious disease… Canisius-Wilhelmina Ziekenhuis, Nigmegen, for his help in identification of P. Romeroi by DNA extraction and gene sequencing. We thank Dr. Sashir Wanjare, Prof. Microbiology, Seth G.S. Medical College KEM Hospital, for help with the microbiological examination. Help from both of them has made this paper possible.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3]