Detection of Candida albicans in oral squamous cell carcinoma by fl uorescence staining technique

Abstract

Background: One of the probable etiologic risk factors of oral squamous cell carcinoma (OSCC)

is Candidal infection, especially by Candida albicans, whose role has not defi nitely been confi rmed.

Some have assigned a primary role to Candida, whereas others consider it as a transient inhabitant.

The debate may be due to lack of an accurate and sensitive revealing technique. By identifying the

presence of Candida, especially in deeper parts of OSCC, the etiologic role may be verifi ed. The

present study was conducted to detect the presence of Candida in OSCC by fl uorescence staining

technique.

Materials and Methods: This study was descriptive experimental. Calcofl uor-white, which

is applied in fl uorescence staining, is a specifi c staining substance for Candida and has a higher

accuracy compared with other common methods. 100 specimens of well-differentiated OSCC

with adequate amount of tissue were retrieved from the archive and two serial sections were

obtained from each one. The fi rst section was stained using the popular histochemical (periodic

acid-Schiff [PAS]) method and then evaluated under a light microscope to detect the presence of

Candida. The second section was stained using fl uorescence staining technique. The sum of counted

Candida in each technique was fed into SPSS software and analyzed by McNamara test. P < 0.001

was considered as signifi cant.

Results: The amount of Candida present in OSCCs was 74% measured by fl uorescence technique.

The sensitivity and specifi city of the two staining techniques were signifi cantly different. These

parameters in the fl uorescence technique were higher than those of the histochemical (PAS)

method, confi rmed by McNamara test showing signifi cantly different results for them (P < 0.001).

The results obtained from the fl uorescence technique had higher accuracy compared with the

histochemical (PAS) method.

Conclusion: Some researchers couldn’t fi nd a considerable number of fungi in OSCC, while

our results revealed more presence of Candida, especially in deeper parts of tissue samples and

probably a more important role for Candida as an etiologic risk factor for OSCC. However, since

the fl uorescence technique had a higher accuracy in the identifi cation of Candida and it was nearly

evident in two-third of the samples, the role of fungi as a primary cause is suggested to be studied

in future investigations.

Key Words: Candida albicans, fl uorescence, oral squamous cell carcinoma