Myxoid angiomyoma of the hard palate: A case report. (Original Article).

Abstract

Angiomyomas are found with some frequency in the female genital tract. They can also appear in both sexes in the gastrointestinal tract and in the skin. The oral cavity is an unusual site for an angiomyoma. In this article, we describe the case of a 74-year-old woman who came to us with a nodule at the palatal midline. Following surgical excision of the growth and stent placement over the wound site, a biopsy analysis was performed. Histology of the removed tissue revealed an unusual variant of an angiomyoma: a myxoid angiomyoma.

Introduction

Leiomyomas (benign smooth-muscle tumors) occur most often in the female genital tract as the so-called uterine fibroid. These tumors can also appear in the gastrointestinal tract and in the skin in both sexes. Leiomyomas can be classified as one of three types: solid, epithelioid (leiomyoblastoma), and vascular (angiomyoma or angioleiomyoma). (1) An unusual variant of the angiomyoma--the myxoid angiomyoma--has been described by Enzinger and Weiss. (2) Angiomyomas are not usually seen in the oral cavity. In this article, we report a case of a palatal lesion that was histologically identified as a mixed angiomyoma.

Case report

During a regularly scheduled prophylactic dental appointment, a white 74-year-old woman expressed concern about a palatal mass. She had first noticed the mass approximately 6 weeks earlier.

According to her medical history, she had been diagnosed with carcinoma in situ of the cervix 9 years earlier, and she had undergone a complete hysterectomy with oophorectomy at that time. Seven years later, a benign sebaceous cyst was removed from the midline of her left breast. She had also undergone several excisions of basal cell carcinomas from her midface over the preceding 35 years, most recently the removal of a lesion from the left ala 4 years earlier. She also had a 50-year history of smoking one pack of cigarettes per day and mild social alcohol intake.

Intraoral examination revealed the presence of a 1-cm soft-tissue mass that involved the midline of the hard palate 2.6 cm posterior to the incisive papilla. The lesion felt firm and had an erythematous surface that featured an ulcerated center and rolled borders (figure 1). No other intraoral abnormality was observed. Perioral examination failed to reveal any lymphadenopathy or other abnormality.

An alginate impression was made of the maxilla to establish a presurgical record. The surgical team was able to alter the resulting cast after recontouring the palate. The cast also allowed for the fabrication of the surgical stent that would cover the surgical site by engaging the undercuts of the maxillary teeth for retention, much like a maxillary orthodontic retainer (figure 2). This procedure was followed by an excisional biopsy of the lesion under local anesthesia. Following the removal of the nodule, the prefabricated acrylic stent was secured in place. The surgeons felt that suturing was not indicated because the stent allowed for tissue adaptation of the surgical site and provided a template for wound healing by secondary intention. As a precautionary measure following the excision of the lesion, the patient was started on penicillin for 5 days and given acetaminophen for analgesia. No postoperative complications were encountered, and the excision site healed completely within 4 weeks.

Histopathologic examination of the lesion identified a fairly well circumscribed myxomatous mass covered with a partially ulcerated mucosal epithelium (figure 3, A). Prominent vascularity was associated with the myxomatous tissue. Some neural structures were also observed. A proliferation of smooth muscle associated with the vascular walls was apparent. The nature of the smooth-muscle proliferation was accentuated by trichrome staining (figure 3, B).

At 4 years, there was no recurrence, and the patient was maintained on a regular recall schedule for evaluation.

Discussion

Smooth-muscle neoplasms (leiomyomas and angiomyomas) of the oral mucosa are well recognized and have been described in the literature. (3-6) The histologically myxoid variant of angiomyoma is far less common and has not been reported in the oral cavity as a distinct entity. Oral leiomyomas with myxoid change, however, have been described. (3)

The clinical diagnosis of a leiomyoma or an angiomyoma is difficult, if not impossible, because there are no distinctive clinical features associated with these tumors; they are usually asymptomatic and have the color of normal mucosa. (1) In our patient, the differential diagnosis included (1) benign fibrous and neural tumors with secondary ulceration, (2) a specific infection, and (3) perhaps necrotizing sialometaplasia. Salivary gland tumors, while common in the palate, are not usually found in the midline, although one of the authors (S.O.K.) has seen several during his career. Thus, our diagnosis rested on the results of microscopic examination.

The histologic differential diagnosis in this case included a nerve sheath myxoma and a neurofibroma with myxomatous change, in addition to the myxoid angiomyoma. Enzinger and Weiss reported that the differential diagnosis could also include nodular fasciitis and myxoma. (2) The diagnosis of myxoid angiomyoma is made considerably easier by histochemical staining--specifically the trichrome stain. Staining biopsy samples with Masson's trichrome shows smooth-muscle cells as red, and collagen in various shades from blue to green. (6) This is how our samples stained, and it enabled us to establish the diagnosis.

Although myxoid changes in soft-tissue tumors are well recognized, they are not always clearly understood. Trauma and the duration of pressure have been suggested as two possible etiologic factors in myxomatous disease, although this is purely speculative. Trauma was noted in our patient, but the duration of pressure was relatively short (6 wk).

Angiomyomas are treated by surgical excision. Recurrences and malignant changes are not common. As always, it is best to examine and identify any abnormality of the oral cavity. Even though myxoid angiomyomas rarely exhibit malignant changes, malignancy must still be ruled out.

Our patient had a surgical stent placed postoperatively to aid in the healing of the surgical site. In addition to the mechanical approximation of the tissue following the excision of a lesion, a stent also (1) keeps the patient more comfortable by protecting the wound from mechanical trauma and local irritation, (2) prevents the formation of exuberant granulation tissue, and (3) acts as a template for the wound healing process. (7) An ideal palatal stent should not irritate the biologic tissues, should not interfere with oral functions, and should be relatively easy to fabricate and maintain. (8)

From the Department of Advanced General Dentistry (Dr. Holder, Dr. Dellinger, and Dr. Livingston), the Department of Diagnostic Sciences (Dr. Krolls), and the Department of Oral and Maxillofacial Surgery (Dr. Hill), University of Mississippi School of Dentistry, Jackson, and the Department of Surgery, University of Mississippi Medical Center, Jackson (Dr. Alemar).

References

(1.) Neville BW, Damm DD. Allen CM, Bouquot JE. Oral and Maxillofacial Pathology. Philadelphia: W.B. Saunders, 1995: 397-8.

(2.) Enzinger FM, Weiss SW. Soft Tissue Tumors. 2nd ed. St. Louis: Mosby, 1988:386-91.

(3.) MacDonald DG. Smooth muscle tumours of the mouth. Br J Oral Surg l969;6:207-14.

(4.) Cherrick HM, Dunlap CL, King OH, Jr. Leiomyomas of the oral cavity. Review of the literature and clinicopathologic study of seven new cases. Oral Surg Oral Med Oral Pathol 1973;35:54-66.

(5.) Natiella JR. Neiders ME, Greene GW. Oral leiomyoma. Report of six cases and a review of the literature. J Oral Pathol 1982;11:353-65.

(6.) Burkes EJ, Jr. Vascular Iciomyoma of the mandible: Report of a case. J Oral Maxillofac Surg 1995;53:65-6.

(7.) Grant DA, Stern IB, Listgarten MA. Periodontics its the Tradition of Gottlieb and Orban. 6th ed. St. Louis: Mosby, 1988:772.

(8.) Rowe NL, Killey HC. Fractures of the Facial Skeleton. 2nd ed (reprint). London: E. & S. Livingston, 1970:738-9.