Clinical features of microinvasive stage I oral carcinoma

This study aimed to analyse a case series of microinvasive (tumour thickness <4 mm) stage I oral squamous cell carcinoma (OSCC), with an emphasis on the clinical features of the tumours.

In total, 32 microinvasive and 67 non-microinvasive stage I lesions, which had been surgically treated, were retrospectively studied and compared. The data analysed included gender, age, risk habits, clinical appearance, lesion site, symptoms, nodal involvement and outcome.

The clinical features of microinvasive lesions meant that, more often than not, they resembled premalignant lesions (P = 0.008), and diagnosis was mainly based on accurate clinical examination rather than the presence of symptoms (P = 0.029). During a median follow-up of 4.5 years, one nodal involvement and one cancer-related death were observed in patients with microinvasive lesions. A significantly higher (P = 0.044) level of nodal involvement was observed in the non-microinvasive lesion group.

Stage I OSCC has a favourable prognosis overall, but nodal recurrence is more common in non-microinvasive cancers. As microinvasive lesions tend to present clinically as premalignant lesions, accurate clinical examination is essential if misdiagnosis of early lesions is to be avoided.