Cryotherapy is effective for treatment of oral verrucous hyperplasia – Case report

Oral verrucous hyperplasia (OVH) is a benign tumor-like lesion characterized by the outward growth of oral stratified squamous epithelium with verrucous surface.¹ Our previous studies demonstrated that topical 5-aminolevulinic acid-mediated photodynamic therapy and cryogun (Brymill Corp., Ellington, CT, USA) cryotherapy are very effective for treatment of OVH and oral leukoplakia lesions, respectively.^1,2 Here, we presented an OVH lesion at the left buccal mucosa of a 29-year-old male patient, which was effectively treated to complete regression by one treatment of cryotherapy.

This 29-year-old male patient came to our oral mucosal disease clinic for treatment of a tumor at the left buccal mucosa for 3 months. Oral examination revealed a painless elevated verrucous lesion measuring 3.0 × 1.5 × 0.8 cm at the left buccal mucosa (Fig. 1A). The patient had betel quid chewing (approximately 20 betel quids per day) and smoking habits (approximately 1.5 packs of cigarettes per day) for 10 years. Under the suspicion of a squamous cell carcinoma, the patient was referred to an oral and maxillofacial surgeon for doing a biopsy. The biopsy report issued one week later showed an OVH lesion. Because the patient refused to do surgery for excision of the OVH lesion, he finally decided to receive cryotherapy for removal of the OVH lesion. After obtaining the signed informed consent, the cryotherapy was performed under local anesthesia. The cryotherapy was composed of intermittent spray of liquid nitrogen for 3 s with a stop of 3 s between two continuous liquid nitrogen sprays with cryogun till the whole tumor was frozen to a hard mass. This procedure was repeated once after a 3-min waiting period to defrost. The analgesic (acetaminophen, 500 mg/tablet, 1 tablet 3 or 4 times/day for 4 days) was prescribed to the patient after cryotherapy treatment. The one-week follow-up oral examination showed nearly complete regression of the OVH lesion with a small residual lesion at the upper side of the previous OVH lesion (arrow) and a residual ulceration at the base of the previous OVH lesion (Fig. 1B). The patient came back three weeks after cryotherapy and the residual ulceration healed but the small residual lesion at the upper side of the previous OVH lesion persisted (arrow, Fig. 1C). No further cryotherapy was given to the patient. The six-week follow-up oral examination demonstrated complete remission of the whole OVH lesion (Fig. 1D). Moreover, no recurrence of the OVH lesion was discovered 3 months after the initial cryotherapy.

Figure 1.

Intraoral photographs of our patient with oral verrucous hyperplasia (OVH) lesion before and after cryotherapy. (A) Initial intraoral photograph showing a verrucous tumor measuring 3.0 × 1.5 × 0.8 cm at the left buccal mucosa. (B) One week after cryotherapy, the follow-up intraoral photograph exhibiting nearly complete regression of the OVH lesion with a small residual lesion at the upper side of the previous OVH lesion (arrow) and a residual ulceration at the base of the previous OVH lesion. (C) Three weeks after cryotherapy, the follow-up intraoral photograph demonstrating the healing of the residual ulceration but the small residual lesion at the upper side of the previous OVH lesion persisted (arrow). (D) Six weeks after cryotherapy, the follow-up intraoral photograph showing complete remission of the whole OVH lesion.

This study showed that cryotherapy was also an effective treatment modality for medium-sized OVH lesion. It is interesting to know why cryotherapy is effective for treatment of the OVH lesion. Previous studies suggested that the mechanisms for cell destruction after cryotherapy are complex, involving both direct and indirect effects.^{3, 4, 5} Direct effects consist of extracellular and intracellular formation of ice crystals that, in turn, disrupt cell and organelle membranes, cellular dehydration, toxic intracellular electrolyte concentration, inhibition of intracellular enzymes, protein damage, thawing effects that cause the cell to swell and rupture, and thermal shock injury to the cells. Indirect effects include vascular changes that lead to ischemic necrosis of the treated tissue and immunologic responses that cause cell damage through a cytotoxic immune mechanism.^{3, 4, 5} Because cryotherapy has the advantages including an easy and bloodless treatment, a very low incidence of secondary infections, and a relative lack of scarring and pain,^{2, 3, 4, 5} it may be a treatment of choice for small and medium-sized OVH lesions.

Declaration of competing interest

The authors have no conflicts of interest relevant to this article.