Oral focal epithelial hyperplasia

ARTICLE

Focal epithelial hyperplasia (FEH) of the oral mucosa (Heck disease) has been observed among American Indians and less frequently in Eskimos from Greenland and Alaska. On the contrary, isolated cases have been reported among Caucasians in the rest of the world. This prevalence of the disease seems to be of genetic predisposition [1-4].

The cause of the disease is a human papilloma virus (HPV) [5-7] and in the majority of the cases DNA of HPV 13 and less frequently of HPV 32 has been identified [4, 8].

In this study we present the first case of FEH in Greece in which HPV 13 was found with PCR analysis and which has been successfully treated with CO₂ laser [9-11].

Case report

A 17 year-old healthy Greek Caucasian girl was referred for persisting oral lesions which the patient had had for one year. On examination she presented multiple, soft and slightly elevated sessile papules, of 2 to 12 mm in diameter. They were located mainly on the inner aspect of the lower lip and to a lesser extent on the parietal mucous membranes and the underside of the tongue. Their colour was reddish to whitish or red, similar to the normal surrounding mucosa (Fig. 1).

The patient complained only of mild discomfort during speaking and eating.

No other viral diseases were clinically seen on the patient's skin or the mucosa. A small cavernous haemangioma had been present on the right half of the lower lip since birth.

Personal and family history were negative.

A diagnosis of HPV infection was suggested and biopsy specimens were surgically removed from the inner aspect of the lower lip under local anesthesia. A part was fixed with 10% formalin and embedded in paraffin for histological examination which revealed: acanthosis, dyskeratosis, parakeratosis, balloon cells, hyperchromasia of nucleus, binucleation and perinuclear clear halo, findings compatible with HPV infection (Fig. 2). The other half of the specimen was snap-frozen and stored at ­ 70° C for PCR examination. This method was used because of its high sensitivity and specificity in the detection and typing of HPVs in humans. Total DNA extraction was performed by the salt extraction method [12]. For the detection and typing of the specific HPV two step analysis was used. A multiprimer set for the L1 gene detecting HPV types 6, 8, 11, 13, 16, 18, 30, 31, 32, 33 and 45 was used for the initial PCR amplification. A band was produced indicating the presence of the virus. A second step including primers for each of the above HPV types was done. The second PCR analysis was positive for HPV 13 only. All reactions were run in duplicate with positive, negative controls and blanks (Fig. 3).

The lesions were removed under local anaesthesia with CO₂ laser set at 5-7 W. The laser operated in a continuous mode. The procedure was carried out with no bleeding and the traumas left with no sutures or dressing. After two weeks all the lesions were healed with no scarring. There have been no recurrences for a period of 20 months (Fig. 4).

Discussion

FEH is clinically characterized by multiple circumscribed, sessile, soft elevated nodules of the oral mucosa which sometimes form clusters. They are reddish or whitish or like the adjoining oral mucosa. In our case the clinical manifestations were similar to those usually reported [1, 4].

The disease affects both sexes and all ages but it has been reported especially in Indians and Eskimos. However, there have been a few cases reported in Caucasians [1, 2]. As far as we know our case is the first one in Greece in a young Caucasian girl.

The diagnosis of FEH can be made clinically but histological examination may show characteristics of viral infection, as in our case. However, the precise diagnosis is made by in situ hybridization or PCR analysis, where two types of viruses have been reported, namely HPV 13 and HPV 32 [5-12]. In our case HPV 13, which is the most common, was found using PCR.

The course of the disease is with mild subjective symptoms and a spontaneous remission is possible. Different therapeutic procedures have been reported and CO₂ laser surgery seems to be one of the best [9-11]. Advantages of this method are the haemostatic effect, the healing without scarring and the compliance of the patient. Our patient has been followed up for 20 months without recurrences.

Accepted on 10/4/00

REFERENCES

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