Discussion
Mucormycosis is an infection due to fungi (order Mucorales) of species Rhizopus, Mucor, Cunninghamella, Apophysomyces, Lichtheimia, Rhizomucor.[4]
These are angioinvasive fungi, which invades kidneys hematogenously as part of multi -organ disease, although isolated renal involvement is also reported. [1, 3]
Mucor is an ubiquitous fungi which reaches the human body through spores entrapped in nasal turbinates or through ingestion , inhalation or interrupted skin. This infection is seen commonly in diabetics, immunocompromised patients such as allograft recipients, HIV patients, patients with malignancy and intravenous (IV) drug abusers. [1,5]
The virulence factor involved in the pathogenesis of Mucorales are high-affinity iron permease (FTR1), Spore coat protein (Cot H) and ADP-ribosylation factor which allows fungi to tolerate a low iron environment, impairing host defences and growth of Mucorales. [6]
Neutrophils are the mainstay to mount a response against mucor, hence patients with neutropenia or dysfunction in neutrophils (steroid use, diabetes Mellitus) results in fulminant fungal infection. [7]
On basis of location, mucormycosis can be divided into rhinocerebral, pulmonary, cutaneous, gastrointestinal, disseminated, and uncommon presentations. [8]
Suspecting and timely diagnosis is required for successful treatment of mucormycosis.
In genitourinary organs, mucormycosis is reported in kidneys, although involvement of other organs reported occasionaly. It can present with flank pain, fever, acute kidney injury, lump. Diagnosis is by clinical suspicion, radiology, smear examination, culture, and histopathological examination. When culture is not available or could not be done, histopathology is the mainstay of diagnosis. [9]
Examination with stains hematoxylin and eosin (H&E) or Grocott methenamine-silver (GMS) or periodic acid-Schiff (PAS) stains show typical broad, nonseptate, irregular, ribbon-shaped (typically 6- to 25-µm diameter), irregular branching at 45-90º. Histopathology from tissue shows necrosis and angioinvasion with neutrophils as predominant inflammatory response. A granulomatous response may be seen in delayed stages. [10]
Treatment can be medical as well as surgical as per the condition of the patient. Amphotericin B (liposomal) is first-line treatment with Posaconazole, isavuconazole as alternatives.
Espejo et al reported a case of bladder mass detected and managed medically. They described the presence of fungal mass in a patient with DM and CKD (chronic kidney disease). [1]
In a case series by Devana et al ,15 patients of isolated renal mucormycosis were described. Ten underwent unilaterally nephrectomy and 2 underwent bilateral nephrectomy whereas 2 were managed medically for mucormycosis. [2]
In our patient patient complained of low-grade fever. Investigations suggested right mild hydronephrosis with no renal changes of mucormycosis with echogenic contents in urinary bladder. Patient was taken up for cystoscopy and stenting. On cystoscopy elongated creamy yellow material wwas seen in urinary bladder. Histopathology suggested mucormycosis in urinary bladder. He was started on oral Posaconazole and improved considerably. Follow up investigation revealed normal kidneys and normal creatinine (1.1mg/dl).