Figure 3: A panoramic radiograph obtained one year after the
intervention demonstrated a significant reduction in the size and
radiolucency of the previously observed mandibular lesion, suggesting
successful treatment.
Discussion :
As found in the literature, brown tumors target a rather young
population, with a highest incidence between 30 and 60 years old with
female predilection, ration 2/3.3,4 The predominant
clinical manifestation is facial swelling which can be painful or
painless. 5 When the mandibular lesion is not yet
externalized, the discovery is then fortuitous as in our case. Brown
tumors most often have many locations, particularly in the long bones
such as the femur, tibia, clavicle, ribs and appear more rarely at the
maxillofacial area.6 When they develop in the facial
region, the most affected bone is the mandibular bone, as in the case
reported.5,7 Bone demineralization is caused by
hypersecretion of PTH, PTH stimulates osteolysis which allows the
release of calcium into the blood. Primary hyperparathyroidism is caused
by gland adenoma in 80% of cases. Secondary hyperparathyroidism is
related to chronic renal failure or vitamin D deficiency. Tertiary
hyperparathyroidism is caused by a long standing non treated secondary
hyperparathyroidism leading to parathyroid hyperplasia. Diagnosis of
maxillary bone lesions caused by hyperparathyroidism is based on
clinical, radiological, biological and anatomopathological
examinations.6,8 Panoramic X-ray is a two-dimensional
dental X-ray examination that shows maxilla mandibular structures and
lesions. It can show fortuitously bone demineralization or well-defined
bone radiolucency. Cervical ultrasound when hyperparathyroidism is
suspected, can show adenoma or hyperplasia of the gland. Scintigraphy on
MIBI is indicated in case of ectopic and posterior adenoma. Biological
examination usually shows hyperparathyroidism associated to:
- Hypercalcemia and hypophosphatemia for Primary HPT
- Hypocalcemia and hyperphosphatemia for Secondary HPT
- increased alkaline phosphatase in both cases
The case reported here presented hyperphosphatemia (1.70 mmol/l) which
is in favor of secondary hyperparathyroidism. The pathological
examination with biopsy of the tumor was not carried out because there
was no indication for surgical intervention for this patient. Regarding
dental condition in the injured area, dental displacements and / or
dental mobility due to the loss of the lamina dura, as well as bone
lysis in the periapical region can be observed, in our patient the
lesion was discovered at an early stage with absence of tooth mobility.
The evolution and resolution of the brown tumor will be more or less
rapid depending on the importance of the bone demineralization as well
as the tumor localization. Either a resolution without sequelae
(disappearance of mobility) or an early loss of teeth will be
observed.4,5 A loss of teeth vitality related to the
lesion and/or canals calcification are also observed, which can lead to
a clinical misdiagnosis and erroneous management consisting of
antibiotics prescription or endodontic treatment. 2The characteristics of the brown tumor are as follows:
- Macroscopic appearance: hard nodular type lesion, firm on palpation,
with or without ulcerated oral mucosa, gray/brown in color, and
haemorrhagic.9,10
- Microscopic appearance: it is a fibrous tissue composed of
fibroblasts, multinucleated giant cells,surrounded by a stroma composed
of numerous blood vessels with clusters of macrophages filled with
deposits of hemosiderin and hemorrhagic areas.9,10
- Radiological aspect: radiolucent osteolytic lesion, uni or
multilocular with defined contours, without invasion of the adjacent
structures bone remodeling zones can be observed associated to
significant osteoclastic activity.9,10
Loss of cortical bone and lamina dura at the level of the affected teeth
may occur in more locally aggressive forms.1,6 Brown
tumors treatment begins with the resolution of the hyperparathyroidism
to hope for the tumor’s resorption and, if necessary, perform a
secondary mass excision.3,6,8,9 Total or subtotal
parathyroidectomy is indicated especially in cases of hyperplasia or
parathyroid adenoma depending on the number of glands affected, as is
the case with our patient, the bone lesion spontaneously regressed after
normalization of the constants, a control X-ray panoramic after one year
is recommanded to objectify the regression of the lesion
In cases of secondary hyperparathyroidism, its resolution requires renal
therapy (graft, renal transplantation, hemodialysis) and/or calcium and
vitamin D supplementation.7