Journal of Indian Society of Pedodontics and Preventive Dentistry
Journal of Indian Society of Pedodontics and Preventive Dentistry
                                                   Official journal of the Indian Society of Pedodontics and Preventive Dentistry                           
Year : 2011  |  Volume : 29  |  Issue : 6  |  Page : 61--65

Oral leiomyoma extending in retromolar region

A Goel1, H Goel2,  
1 Department of Pedodontics and Preventive Dentistry, D. J. College of Dental Sciences and Research, Modinagar, Uttar Pradesh, India
2 Department of Prosthodontics, D. J. College of Dental Sciences and Research, Modinagar, Uttar Pradesh, India

Correspondence Address:
A Goel
Flat No. 212, Imperial Block I, Supertech Estate, Sector 9, Vaishali, Ghaziabad, Uttar Pradesh - 201 010


Leiomyoma is a benign smooth muscle tumor that rarely affects children and occurs most frequently in the uterine myometrium and gastrointestinal tract. Its occurrence in the oral cavity is considered rare probably because of the scarcity of smooth muscle tissue in the oral cavity. The most common intraoral sites for leiomyoma are lips, palate and tongue. The purpose of this case report is to present the clinical features, diagnosis and treatment of a rare case of oral leiomyoma in a 13-year-old girl with a 4-month history of a swelling in her left mandibular area extending from first molar to retromolar region.

How to cite this article:
Goel A, Goel H. Oral leiomyoma extending in retromolar region.J Indian Soc Pedod Prev Dent 2011;29:61-65

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Goel A, Goel H. Oral leiomyoma extending in retromolar region. J Indian Soc Pedod Prev Dent [serial online] 2011 [cited 2022 Oct 7 ];29:61-65
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Leiomyomas are benign smooth muscle neoplasms that are classified according to the World Health Organization (WHO) under three histological subtypes: solid leiomyoma, angioleiomyoma (vascular leiomyoma) and epithelioid leiomyoma (bizarre leiomyoma/leiomyoblastoma); the last subtype is the least common. [1] Solid leiomyomas are typically normal in color and well-circumscribed tumors that consist of interlacing bundles of spindle-shaped smooth muscle cells with elongated, pale-staining and blunt-ended nuclei. Mitotic figures are uncommon in them. Angioleiomyomas may show bluish hue and are well-circumscribed lesions that demonstrate multiple torturous blood vessels with thickened walls caused by hyperplasia of their smooth muscle coats. Intervening bundles of smooth muscle cells are found between the vessels. Epithelioid leiomyomas are composed primarily of epithelioid cells rather than spindle cells. [2] 95% of the leiomyomas occur in the uterine myometrium, with the gastrointestinal tract and skin less commonly affected. [3] Oral leiomyomas are infrequently found. Less than 150 cases have been published through the year 2002 since Blanc's report in 1884. [4] In a series of 7748 smooth muscle tumors of all types, only 5 (0.06%) were found in the oral cavity. [3] Survey of the published cases has revealed that angioleiomyomas represent 64-66% of all variants of oral leiomyomas, followed by solid ones. [5],[6] When encountered, they most often occur in tongue, palate(hard or soft), buccal mucosa, lip and rarely mandibular trigone. [6],[7]

Leiomyomas are uncommon in the oral cavity because of paucity of smooth muscles in the mouth. Stout [8] suggested that the source of smooth muscle in oral cavity can be tunica media of the blood vessel wall, whereas Glass [9] considered the smooth muscle of ductus lingualis and suggested the circumvallate papillae as another possible source. Oral leiomyomas can appear at any age, but the greatest prevalence is in the age group of 40-59 years, more frequent in men than in women with a 1.43:1 ratio. [6],[7] Our case report describes an extremely rare case of leiomyoma of the retromolar region in a pediatric patient.

 Case Report

A 13-year-old girl reported to our dental clinic with the chief complaint of painful gingival swelling of 4 months duration, distal to mandibular left second molar which was gradually increasing in size. On extraoral examination [Figure 1], slight swelling was seen on the left side of the face with the overlying skin being normal. Intraoral examination [Figure 2] revealed a non-fluctuant, non-suppurative, slightly ulcerated gingival mass, distal and buccal to the lower left first molar tooth extending in ramal and retromolar region. The mass measured 3 × 3 cm approx. in the greatest dimensions. Permanent mandibular left first and second molars (36, 37) were grade II mobile. No anesthesia/paresthesia was present. Past medical history was unremarkable. The patient appeared to be well with history of no prior hospitalization or major illnesses. The family history was noncontributory. No palpable cervical lymph nodes were found. All the permanent teeth except for third molars were erupted. An orthopantomogram [Figure 3] of the patient was taken which revealed no dental cause for the lesion but a radiolucent shadow of the soft tissue growth with erosion of bone in second molar and retromolar region.{Figure 1}{Figure 2}{Figure 3}

In view of the isolated, non-fluctuant nature of the mass, a provisional diagnosis of fibroma or lipoma was made and incisional biopsy was performed under local anesthesia to make a definitive diagnosis. A 3 × 2 × 1 cm wedge was placed in 10% neutral buffered formalin and submitted for microscopic examination. Histological report confirmed the leiomyoma. Therefore, after making routine blood investigations and taking pre-anesthetic clearance, the patient was appointed for surgical excision of the mass by our oral surgeon, under general anesthesia. Tumor mass was excised with cautery, along with the overlying mucosa and surrounding tissue. All the three permanent molars were extracted and peripheral osteotomy was done [Figure 4]. After thorough hemostasis, suturing was done with 4-0 mersilk and the excised mass was sent for histological examination.{Figure 4}

Macroscopically [Figure 5], the excised mass was brownish white in color, elastic in consistency, irregular in shape and encapsulated. The histological report revealed that the tumor consisted of interlacing fascicles of spindle cells with intervening scattered blood vessels [Figure 6]. The cells showed mild pleomorphism and had oval to spindle nuclei with blunt ends [Figure 7]. Smooth muscle actin (SMA) positivity was seen suggestive of leiomyoma. Post-surgical recovery of the patient was uneventful. Sutures were removed after 7 days [Figure 8]. After 3 months, removable partial denture was fabricated for extracted 36, 37 so as to restore the function [Figure 9]. The patient was followed up for 2 years.{Figure 5}{Figure 6}{Figure 7}{Figure 8}{Figure 9}


Oral leiomyoma has a low incidence. It usually presents as a slow-growing mass that may or may not exhibit ulceration. [10] Symptoms also vary; patients often seek a general dental consultation for treatment of what they perceive as a painful tooth, which was also true in this case. Main symptoms are pain, tooth mobility or even difficulty in chewing, usually when the tumor is located in tongue, lips or palate. [6]

Solid leiomyoma of the mandible is extremely rare, with very few cases having been reported in the literature. In a review of many subcutaneous and deep soft tissue leiomyomas, these tumors have been reported to be slow growing. [11] However, in half of the previously reported cases of leiomyoma of the mandible, the tendency for rapid growth was recognized. [12],[13] The leiomyoma in this patient also showed rapid increase in size, suggestive of malignancy. Due to its unspecific clinical presentation, diagnosis was made after histological study which showed the typical small and spindle smooth muscle cells with a uniform size without necrotic areas and no malignancy criteria (number of mitotic figures per field). Vague, interlacing fascicular arrangements are often seen in the solid type, whereas the angiomyoma subtype demonstrates prominent, variably sized blood vessels enclosed by a proliferation of smooth muscle cells. More specific analysis and more precise differential diagnosis can be achieved with immunohistochemical studies.

Several oral tumors should be included in differential diagnosis: benign lesions such as fibroma, myofibroma, neurofibroma, lipoma, mucocele, schwannoma or malignant ones such as leiomyosarcoma. In this case, SMA positivity in immmunohistological examination confirmed smooth muscle origin, and thus ruled out fibroblastic, neural, and vascular tumors.

There was some discussion in regard to this case about distinguishing between leiomyoma and leiomyosarcoma. The malignant counterpart, the leiomyosarcoma, should be taken into account when the number of mitotic figures per field is over 10, as the mitotic count in sections stained with hematoxylin-eosin has been used for differentiating between benign and malignant conditions. [13],[14],[15] Cotran et al.[16] stated that histological features indicative of uterine smooth muscle malignancy include more than 10 mitoses per 10 high-power field (HPF) with or without cellular atypia and 5-10 mitoses per 10 HPF with atypia. Tumors having 1-4 mitoses are best considered potentially malignant especially if they are large and have areas of necrosis and significant nuclear atypia. The tumor doubling time is often useful clinically in distinguishing malignant from benign lesions. [17] Shimamoto et al.[18] reported the doubling time of gastric leiomyoma to range from 20.3 to 103 months (mean 48 months) and that of leiomyosarcoma to range from 5.2 to 11.9 months (mean 8 months). The maximum tumor diameter can also be used for the assessment of malignancy. Diameter larger than 30 mm was reported as an indicator of malignancy in gastric myosarcoma. [19] In our case also, the diameter was 30 mm, thus malignancy was suspected. Surgical excision of leiomyoma appears to be the best option for treatment and it has been the only one used till date. There has been only one recurrence case, 2 weeks after the excision of the lesion, so it was suggested that the tumor was not removed totally. [6] It is important to obtain a complete resection in order to avoid recurrences. In our case, because of the large size of the mass and grade II mobile 36, 37, and as the differentiation between leiomyoma and low-grade leiomyosarcoma is not always easy, peripheral osteotomy with extraction of involved molars was planned. Moreover, it has been noted that smooth muscle neoplasms in the orofacial region have a higher proportional incidence of malignancy than their counterparts in the female genital tract. [20] In the case of our patient, postoperative recovery was uneventful and there has been no evidence of recurrence 2 years after excision.


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