Fine-Needle Aspiration is a Fast and Valuable Method for Early Diagnosis of Fungal Infections

Fine-Needle Aspiration is a Fast and Valuable Method for Early Diagnosis of Fungal Infections

Introduction

Over the past decades, the incidence and severity of opportunistic infections has increased because of increased number of patients with immunocompromised conditions such as AIDS, organ transplantation, and cancer chemotherapy. Fine-needle aspiration (FNA) emerges as one of the major diagnostic tools in mycology. Nevertheless, culture results may take days to weeks which cause a delay in initiation of treatment. FNA can offer exact results in as early as minutes thus expediting the treatment initiation process.

Aim

A retrospective study was conducted to illustrate the efficacy of FNA cytology in early diagnosis of fungal infections.

Methodology

The computerized electronic system of the University of Texas Medical Branch (UTMB) was used to retrieve all FNAs from superficial and deep lesions obtained from various sites with the diagnosis of fungal infection. While examining the stained slides, as fungal organisms were identified, special stains such as Grocott’s methenamine silver (GMS), periodic acid-Schiff’s (PAS) or mucicarmine were utilized to support the diagnosis. The FNA results were associated with the clinical-radiological findings recovered from electronic medical charts, in addition to microbial culture and serology results. A total of 15 cases [mean age was 47.6 years (26–70) and consisted of 14 males and one female] were identified. Each case was investigated for underlying predisposing conditions, FNA source, radiologic findings, culture, and serology results.

Results

Cases were identified from the following sites: lung (8), cervical lymph nodes (4), soft tissue (2), and retroperitoneal lymph node (1).

Predisposing conditions were observed in 11 patients: HIV (5), malignancy (3), and post-transplant (3).

Imaging impression was typically malignancy vs infection.

The diagnosis of fungal infection was done by FNA cytology in all 15 cases.

The presumptive genus specific diagnoses based on yeast morphology were given in 12 cases (5 Histoplasma, 4 Cryptococcus, and 3 Coccidioides) (Table 1).

In rest of the 3 cases, Blastomyces vs. Cryptococcus was the differential for one case; budding yeasts could not be typed on smears or core biopsies in another case, and extensive necrosis precluded fungal typing in the last case.

Diagnosis of fungal infection was offered within 24 h in 9 cases, (four during onsite evaluation).

Microbial cultures were confirmatory in 7 cases, and 5 cases showed negative cultures with positive serology.

Among all 15 cases, fourteen were discharged in good condition, and one died because of heart graft failure.

Conclusion

FNA cytology was proven to be a rapid and reliable tool for early diagnosis of fungal infections, allowing a prompt initiation of appropriate management and escalating the chances of survival.

Source: George B, Rivera Rolon MDM, Clement CG. Role of fine-needle aspiration cytology in early diagnosis of fungal infections. Diagn Cytopathol. 2020;48(7):645–651.