Establishing reference values for normal tongue squamous cells: An investigation of atypical changes

In cytological evaluation, atypical cells are often recognized by comparing them to presumed "normal" counterparts and judging the extent of morphological deviation. However, there is no clear or universally accepted definition of what constitutes a "normal cell," and the assessment often relies on the examiner's subjective judgment. This paper aims to establish the reference values for the cytological evaluation of the tongue mucosa by quantitatively analyzing nuclear-to-cytoplasmic ratios (NCRs) and the clarity of the features of both nuclear and cytoplasm.

Cytological specimens from seven patients (three males and four females; average age, 62.4 years old) with tongue mucosal lesions were collected (with the Papanicolaou [Pap] stain). Acquired images were analyzed using ImageJ software. We quantified NCRs and brightness values (BV). Statistical analysis was performed using the Steel-Dwass test.

Significant differences in NCR and nuclear BV were observed across Pap Classes 1, 3, and 5. Reference values for normal cells were defined as a mean NCR of 0.031 ± 0.015 for Class 1, 0.074 ± 0.048 for Class 3, and 0.307 ± 0.170 for Class 5. The nuclear BV range widened with increasing Class: 68.90-145.16 (Class 1), 49.91-163.40 (Class 3), and 28.11-183.54 (Class 5).

Our findings suggest that NCR and nuclear brightness can be used as objective criteria for evaluating tongue mucosal cells. For the detection and diagnosis of oral malignant disorders in early stage, the result is a kind of criterion.