Mucor pyelonephritis. Report of a case diagnosed by urine cytology, with diagnostic considerations in the workup of funguria

Mucormycosis: Cytomorphological Spectrum in Fine-Needle Aspiration Cytology

Background

Mucormycosis is a fungal infection that can affect multiple organs. The role of fine-needle aspiration cytology (FNAC) in its diagnosis is not well documented.

Aim

The objective of this study was to describe the detailed cytomorphologic features of mucormycosis on FNAC samples.

Materials and Methods

A retrospective analysis of all cases diagnosed as mucormycosis on FNAC between January 2014 and July 2021 was performed for detailed cytomorphological evaluation and correlation to clinical data and microbiological studies wherever available. FNA was computed tomography-guided (n = 38), ultrasonography-guided (n = 31) or palpation-guided (n = 12), and slides were reviewed in two cases.

Results

A total of 83 cases of mucormycosis were evaluated. An immunocompromised setting was observed in 48 cases. The most common site of FNA was the lung (n = 57) followed by liver, soft tissue, palate, mediastinum, orbital/ocular region, and lymph node. Isolated renal involvement, a unique feature, was seen in seven cases. The aspirates were necrotic to pus-like or blood-mixed particulate. Broad, nonseptate, foldable, ribbon-like fungal hyphae showing right-angled branching were seen. The tissue reaction was predominantly necro-inflammatory (n = 36), bland necrotic (n = 22), mixed inflammatory (n = 16), suppurative (n = 5), necrotizing granulomatous (n = 3), and granulomatous (n = 1). Immunocompromised patients showed mixed inflammatory responses more frequently. Fungal culture was positive for Rhizopus species in 2/13 cases and molecular testing in two additional cases corresponding to Rhizopus and Syncephalastrum spp.

Conclusion

FNA provides quick and conclusive diagnosis of mucormycosis from varied anatomic sites enabling prompt institution of therapy. The tissue response is variable and to some extent dependent on the immune status of the patient.

Rhinocerebral mucormycosis diagnosis by aspiration cytology

Rhinocerebral mucormycosis is a rapidly progressing, often fatal fungal infection that occurs commonly in diabetics and immunocompromised individuals. We present 2 cases of rhinocerebral mucormycosis with a paranasal mass. One patient had an intracranial extension. Nasal scrapings and fine-needle aspiration cytology (FNAC) of the paranasal masses showed fungal hyphae morphologically resembling Mucor. Surgical material showed features of mucormycosis. FNAC and scrape smears can give a conclusive diagnosis of mucormycosis, and the patient can be treated with appropriate antifungal therapy and surgical debridement. Preoperative cytology is an effective technique to establish a diagnosis of mucormycosis and obviates the need for a preoperative biopsy.

Renal mucormycosis in the HIV patient

Mucormycosis is an increasingly recognized opportunistic infection. It usually affects patients with debilitating conditions such as cancer, diabetes mellitus, renal failure, and extensive burns. Mucor infection has also been described in human immunodeficiency virus (HIV) patients. The most common clinical presentations are the cerebral, cutaneous, and renal forms. We describe a unique case of bilateral renal mucormycosis presenting with renal failure in an HIV-infected patient. In the immunosuppressed host, a history of intravenous (IV) drug abuse associated with symptoms of pyelonephritis should alert the clinician to the possibility of mucor infection. Blood and urine culture are often negative. The diagnosis is made histologically in most cases. The treatment of HIV patients with mucormycosis and renal failure includes hemodialysis, nephrectomy, and intravenous amphotericin in addition to antiretroviral therapy. Bilateral renal involvement with Mucor carries a poor prognosis.

Fungal infections of the genitourinary system: manifestations, diagnosis, and treatment

There is an increasing pool of immunocompromised patients who are at an increased risk to fungi infections, which now cause 8% of nosocomial infections. Premature infants and elderly, transplant, and HIV patients are prime candidates for invasive fungal infections. The genitourinary system can be a source or target of disseminated fungal infection. Although candidal species are the most frequent pathogen, other species such as aspergila, cryptoccoccus have become major pathogens. "Environmental fungi," which include blastomyces, coccidioides and histoplasma, have become more aggressive in the vulnerable patient.