The patient’s chief complaint was the facial disfigurement and pain produced by the enlargement in the left mandibular area. She also complained of some difficulty swallowing along with mobility and displacement (supereruption) of the mandibular left first molar tooth (#19). (Figures 1-3)
Past Medical History
Other than the facial deformity, the patient was in good general health with no significant medical problems. She had two normal full-term pregnancies, giving birth to a single child in 1999 and twins in 2000. She was pregnant, in the first trimester, with her fourth child at the time of her presentation in February 2002.
She denied any known allergies. She was taking no medication other than prenatal vitamins. A review of systems on physical examination was entirely negative.
History of Present Illness
The patient had been seen in early January 1994 for evaluation of intraoral enlargement of the left mandible in the same general location as the current lesion, although no extraoral involvement was noted as in the February 2002 presentation. Radiographic evaluation at that time (Figure 4) had revealed a “cystic” lesion measuring 3.5 by 3.0 cm associated with an impacted mandibular left third molar (#17).
Tooth #17 and the lesion were removed by another clinician and the defect packed with bovine hemostatic collagen. Following histopathologic diagnosis, it was decided to follow the lesion closely. The patient returned for follow-up in March 1994, two months after the surgery, at which time a panoramic radiograph “looked good.” The next recall was scheduled for June 1994, but the patient failed to return at that time and was lost to follow-up.
The patient first presented to us for evaluation in early February 2002, nearly 8 years following her last visit with the previous clinician. She reported that she had been unaware of any problems in this area until approximately 2 years previously when some extraoral swelling first became evident. At about this same time, however, her husband lost his job due to a disabling injury and she delayed seeking treatment due to financial concerns.
For the last two years she had been having steadily increasing pain in the area of the mandibular enlargement. She had managed this pain by compressing the lateral portion of the mandible until it “burst.” She had been doing this with increasing frequency, and she now had to perform this decompression twice a week.
Clinical examination revealed diffuse enlargement of the left body of the mandible, extending into the retromolar region and involving the entire alveolar ridge area. While there was some mild expansion lingually, most of the expansion was toward the buccal aspect, partially obliterating the mucobuccal vestibule. (Figure 5) The mucosa overlying the alveolar ridge was intact. The maxillary molar teeth were occluding on the elevated and expanded mandibular alveolar ridge mucosa, producing some visible indentation of the mucosa corresponding to the maxillary molar cusp tips. (Figure 6) Palpation of the mass revealed crepitus along the alveolus around teeth #19 and #20. Distant to these teeth, the mass was “woody” on palpation.
Of note, the mandibular left second molar (#18) was found to be missing on presentation to our service. This tooth had been present at the time of the initial surgery in 1994. When questioned about tooth #18, the patient reported it was extracted at about the time the swelling reappeared in 2000. Mobility of the tooth was cited as the reason for the extraction. The recurrent swelling was noted by that practitioner but she reported being told, “it was a benign lesion and not to worry about it.”
A panoramic radiograph revealed a markedly expansile, multilocular radiolucent lesion of the left mandible. The borders of the lesion were well defined and, despite the multilocular appearance, it maintained a roughly symmetrical growth pattern. The lesion extended anteriorly to the mandibular left first premolar. Posteriorly, it appeared to extend upward into the ramus slightly and obliterated the normal architecture of the angle. Significant buccal expansion was present, but there appeared to be an intact rim of cortical bone covering the expanded buccal cortex. Superior expansion of the alveolar ridge was also noted. Slight superior displacement of the first molar and second premolar was observed. Distal root resorption of the first molar was also present. Internally, the radiolucent lesion showed numerous bony septations, compartmentalizing the lesion into varying sized locules. (Figure 7)
A lateral cephalometric radiograph (Figure 8) showed essentially the same features. The uninvolved right inferior border of the mandible could be easily visualized through the destructive radiolucent lesion in the left mandible. The lower border of the left mandible appeared to be bowed inferiorly by the expanding mass, a feature that was not as clearly appreciated in the panoramic film. A very thin but intact layer of cortical bone appeared to be present covering this expansion of the inferior border.
A posterior-anterior exposure of the mandible revealed the extent of the buccal expansion, but added little additional information. (Figure 9)
Due to the extent of the surgery anticipated to adequately treat the clinical lesion and the possible untoward effects of such surgery on a developing fetus, the treatment plan called for delaying definitive therapy until the post-partum period. Tooth #19 was extracted in April 2002, due to its mobility and superior displacement. At the time of extraction, portions of the lesion were curetted in order to harvest tissue for microscopic examination and verify the provisional diagnosis. Where possible, disruption of the multiple cystic spaces was attempted during the curettage to facilitate decompression of the lesion. The lesion was packed open in an attempt to control re-accumulation of fluid that was deemed responsible for the patient's pain and increasing lesional size.
The patient returned for follow-up approximately one month later. An estimated 20% reduction in tumor size was noted clinically with less subjective complaints of compressive pressure, pain, and dysphagia. The lesion was re-packed in an attempt to buy time until delivery of the child. By the time of delivery, however, the attempt at decompression of the lesion was failing and most of the earlier reduction in tumor size had recurred. Two months following delivery, allowing sufficient time for the patient to wean the newborn, a hemimandibulectomy was performed.
Histologic examination revealed curetted fragments of a hard and soft tissue specimen with the architecture of a cyst. The lumen of the cyst was lined by epithelium and was supported by an underlying connective tissue wall of fairly uniform thickness. In many areas, a rim of trabecular bone encased the cystic lesion. (Figure 10)