A multidisciplinary approach to diagnosis and treatment of plasma cell neoplasm of a lower jaw

Summary

Introduction and aim: The presented case study documents the course of diagnosis and treatment of plasma cell neoplasia of the lower jaw in a 79-years-old female patient. The aim is to highlight the possibility of plasmacytoma manifestation in the differential diagnosis of jawbone lesions and to emphasize the importance of interdisciplinary cooperation, in this case between the dentoalveolar/maxillofacial surgeon and the haematooncologist.

Case description: The patient was first examined at our facility in November 2023 upon the request of a general dental practitioner due to recurrent difficulties following extraction of the right permanent lower second molar (tooth #47), which had been performed two months earlier. In 2021, the patient underwent surgery for ovarian carcinoma and had no history of diabetes, bleeding disorders, shortness of breath, or other illnesses. She was not using any medications affecting bone metabolism.

Based on the clinical findings, duration of symptoms, OPG image showing noticeable poorly defined radiolucency of the mandibular body in the area of missing teeth, and laboratory tests, a working diagnosis of osteomyelitis of the mandibular body on the right side was established. Empirical treatment with oral broad-spectrum antibiotics of the penicillin class was initiated promptly and resulted in clinical improvement. Cone-beam computed tomography (CBCT)
performed two days after the initial examination revealed osteolytic indistinctly demarcated changes causing lingual wall resorption of the mandibular body reaching to the lower edge of the mandible in the region of the molars on the lower right side. This radiological finding raised suspicion of malignant neoplasm of the lower jaw. Subsequent CT scan with contrast confirmed soft tissue infiltration and the osteolytic nature of the lesion described above. Based on these findings, a diagnostic biopsy of the pathological tissue was indicated and performed, revealing plasma cell neoplasia. In the differential diagnosis, it was necessary to distinguish whether it was a solitary bone plasmacytoma with extraosseous propagation or multiple myeloma infiltration. The patient was referred for haematological examination to a specialized clinic where a definitive diagnosis of multiple myeloma was established. There the patient was treated with a triple combination of bortezomide, lenalidomide, and dexamethasone. The first cycle of this treatment resulted in complete regression of the intraoral lesion and healing of the extraction socket at the site of tooth #47.

Conclusion: This case study highlights the rare but possible occurrence of oral plasmacytomas and emphasizes the importance of interdisciplinary collaboration.

Keywords:

plasmacytoma, osteomyelitis, soft-tissue expansion, osteolytic lesion, multiple myeloma