A 17-year-old patient came to the oral surgery department with a swelling on lower left side of mandible. The swelling was first noticed one year back, it has slowly progressed in size since then. On clinical examination, a bony hard swelling was palpable in the lower left buccal vestibule intraorally and anterior to the angle of mandible extraorally. The lymph nodes were not palpable.
Radiographic examination showed a well-circumscribed radiolucency in the body of mandible, involving the roots of left mandibular molars and premolars. A large carious defect was visible in the mandibular first molar, distal root of involved second molar showed a some degree of resorption.
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| Radiograph shows well demarcated radiolucent area involving roots of mandibular molars and premolars |
The radiographic differential was extensive including odontogenic cysts, tumors, and other benign entities.
When the surgeon aspirated the cavity, a bloody aspirate was noted. She still decided to go in for an incisional biopsy. During the procedure she aspirated more than 15 ml of bloody fluid. She was able to scrape off some tissue from the bone margins. From her description of an empty cavity with almost no tissue and her having to scrape off tissue from the bone margins, we were favoring a diagnosis of traumatic bone cyst. However, the resorption of teeth didn't fit.
The histopathology results were quite surprising.
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| Histopathological slide showing epithelial lining, granulation tissue and chronic inflammatory cells |
Histopathological examination showed granulation tissue partially lined by non-keratinized stratified squamous epithelium. The granulation tissue supported a moderate infiltrate of predominantly chronic inflammatory cells. Based on these results, a definitive diagnosis of radicular cyst (periodical cyst) was made.
Dr. K's Comments:
Radicular Cysts:
The surgeons were as surprised by this presentation as we were. They extracted the tooth, inserted asdrain and asked the patient to return for followup in two weeks. The patient's father insisted that another biopsy be performed at that time, and this time he wanted his pathologist to look at it. His pathologist did a lot of unrequired immunohistochemistry to determine that we were right the first time. His bone is growing back and once the cavity is sufficiently marsupialized, they will excise it.
Although radicular cysts are very common in the jaws, a presentation like this is odd. They usually don't attain such large sizes, or contain so much bloody fluid. Resorption of tooth roots has been reported but it is rare.
The surgeons were as surprised by this presentation as we were. They extracted the tooth, inserted asdrain and asked the patient to return for followup in two weeks. The patient's father insisted that another biopsy be performed at that time, and this time he wanted his pathologist to look at it. His pathologist did a lot of unrequired immunohistochemistry to determine that we were right the first time. His bone is growing back and once the cavity is sufficiently marsupialized, they will excise it.
Although radicular cysts are very common in the jaws, a presentation like this is odd. They usually don't attain such large sizes, or contain so much bloody fluid. Resorption of tooth roots has been reported but it is rare.
