Introduction
Squamous cell carcinomas (SCC) represent more than 90% of the upper aerodigestive tract cancers and can affect the mucosa of the oral cavity, pharynx and larynx. Worldwide, they represent the 8th most common cancer and even rank 2nd when the risk factors tobacco and alcohol are simultaneously present [1]. It has been reported that these cancers are 15 times more frequent when tobacco and alcohol are consumed synergistically [2]. Indeed, the alcohol-smoking patient, in his 6th decade of age with a low socio-economic lifestyle, is considered to be the most frequent patient profile of SCC in the upper aerodigestive tract, and more specifically the oral SCC [1]. However, recently, two other population profiles are emerging for the oral SCC, with an increasing trend in elderly women, possibly linked with denture trauma and toxic exposure [3] and a tendency of increasing tongue cancers in young white women [4] [5]. While HPV infection was associated with the increasing incidence of oropharyngeal cancers in nonsmoker young patients, no evident association with oral and tongue cancer in young women has been found. Tobacco and alcohol consumption seem to have a limited link with these two patient profiles [6] [3]. Other risk factors, such as cannabis consumption, environmental factors, dietary factors, body mass index, dental hygiene, immunosuppression, genetic and familial factors, viral infection, and co-morbidities have been suggested [7]. Some inflammatory diseases and potentially malignant disorders are also likely to degenerate and may be linked to the increased incidence of SCC. Among these, lichen planus is reported.
Lichen planus (LP) is a chronic muco-cutaneous inflammatory disease which can affect the skin and appendages, but more frequently the mucosal membranes and more specifically the oral mucosa. Oral lichen planus (OLP) affects 1 to 2% of the population with a slightly higher prevalence in women (60 to 65%) [8] [9]. The average age of onset is between 30 and 60 years of age. Clinical and histological diagnosis criteria of OLP has been well defined and updated in a recent report published by a group of experts in a workshop organized by the collaborating center of the World Health Organization (WHO) for oral cancer in the UK. These criteria, mainly based on clinical characteristics, are summarized in table 1 [10].
OLP is often discovered during a routine consultation and progresses in flare-ups, with phases of remission and exacerbation. The lesion is preferentially located on the cheek mucosa and at the lower vestibular side, but is also detected on the dorsal surface and lateral edges of the tongue, as well as on the attached gingiva [11]. After several years of evolution, OLP is characterized by mucosal atrophy and fibrosis. The physiopathology of OLP is still not elucidated and relies on immunological hypotheses, and may be associated with some autoimmune pathologies like chronic hepatitis, myasthenia gravis, ulcerative colitis [11].
Since several clinical studies have shown that OLP has an increased risk of malignant transformation, the WHO has classified this entity among “Oral Potentially Malignant Disorders” [10]. Potentially malignant lesions are a morphological alteration of the tissue in which cancer has a greater chance of occurring than in tissue without apparent modification [12]. Even though the incidence and the risk of OLP to evolve into cancer has been widely discussed, controversies exist between authors [13] [14] [15]. The difficulty is to understand whether OLP has an intrinsic potential for malignant transformation and whether this is accentuated by other factors.
Although rare, some cases of tongue cancer in pregnant women have been previously reported, but not arising from a potentially malignant disorder : [16] [17] [18]. Among signaling pathways involved in tumor development, pregnancy induces physiological changes that may promote neoplastic growth, such as changes in vascular networks, elevated metabolism, increased circulating growth factors, and hormonal responses, which may be amplified mediated by estrogen and progesterone receptors [19].
Hereafter, we report a rare case of a young pregnant patient presenting a tongue SCC diagnosed concomitantly with an OLP.