Maxillary and mandibular hyperparathyroidism.

Brown tumor is a focal lesion differentiated from other giant cell tumor by the presence of hyperparathyroidism. These lesions are non-neoplastic and they appear as a mass with partly cystic and partly solid areas. Clinically they are slow growing lesions that can be locally destructive resulting in variety of symptoms such as significant bone swelling, pain and pathological fracture. Here is a female patient of 26 years with brown tumor involving mandible, maxilla and left knee joint.

INTRODUCTION

Brown tumor is one of the lesions that develop in patients with hyperparathyroidism and it affects the jaw bones occasionally. Brown tumor focal lesion results from abnormal bone metabolism in hyperparathyroidism. Histologically it is difficult to differentiate from other giant cell tumors, so clinical diagnosis is made with the findings of hyperparathyroidism. Although initially associated with primary hyperthyroidism, they are being seen with greater frequency of secondary hyperparathyroidism.[12] We report a rare case of browns tumor of maxilla, mandible, and left knee joint in a 21-year-old female patient.

CASE REPORT

A 21-year-old female reported to the department of oral and maxillofacial surgery with complaint of a painless swelling in the mandible and posterior maxilla bilaterally [Figures 1–3], left lateral wall of the nose and left knee joint for the past three years, which was growing slowly; swelling started in the mandible first then in maxilla and later in lateral wall of the nose and knee joint. Clinical examination and CT scan showed a diffused swelling in the mandible measuring 6 × 7 cm and diffused swelling in the posterior maxilla at the tuberosity region; on the right side it measures 4 × 2 cm and 2 × 2 cm on the left side, and lateral wall of the nose measures 1 × 2 cm and left knee measures 10 × 6 cm [Figures 4–7]. Skin over the swelling was normal and pinchable, mouth opening was normal, teeth involved were mobile.

Figure 1

Preoperative picture showing left maxillary tumor

Figure 3

Preoperative picture showing mandibular tumor

Figure 4

CT scan showing tumor at mandibular region and right lateral wall of the nose

Figure 7

X-ray showing tumor at left knee joint

Preoperative picture showing right maxillary tumor

CT scan showing tumor at mandibular region

CT scan showing tumor at right maxillary region

CT scan was evident for a large non-homogenously enhancing mixed density lesion. An incisional biopsy showed numerous osteoclastic giant cells with fibroblastic proliferation and areas of hemorrhage were seen with no evidence of malignancy. The histopathological features were suggestive of reparative giant cell granuloma. Routine blood investigation like HB, BT, CT, ESR, total WBC count, platelet count, and biochemical examination like thyroid profile, serum calcium, parathormone levels, FBS, and urine examination for deposits and albumin was done. The blood and urine investigation showed normal values except for the hemoglobin, which was below normal value and wide increased in the parathormone levels [Table 1]. Two units of pre-surgical blood transfusion and one unit of transfusion postoperatively were given to maintain the hemoglobin levels. Surgery was performed under general anesthesia; the mandibular tumor site was approached extraorally through bilateral submandibular incision along with chin sparing lip split technique. The mandibular mass was removed by segmental mandibulectomy, and bilateral maxillary mass was approached through the mandibular resected site and posterior maxillectomy done bilaterally till the clear pterygoid plates were seen and lateral nasal lesion was approached intra orally [Figures 8 and 9]. Reconstruction plate was used to maintain the contour of the mandible [Figure 10]; primary closure was achieved in the mandible [Figure 11] and lateral wall of the nose, but posterior maxilla was left to heal by secondary intention. The resected specimen was sent for histopathological examination; the histopathological slide with eosin and hematoxylin section with 40× magnification diagnosed as Brown tumor [Figure 12]. The case was further referred to endocrinologist for further management of hyperparathyroidism and was reviewed for three years, which showed no signs of recurrence.

Table 1

Biochemical investigation chart

Figure 8

Resected mandibular segment

Figure 9

Resected maxillary site

Figure 10

Reconstruction plate in position

Figure 11

Postoperative extraoral picture

Figure 12

Many osteoclasts like multinucleated giant cells and fi broblast with hemosiderin deposits

DISCUSSION

Ostitis fibrosa cystica as a manifestation of primary hyperparathyroidism was initially described by von Recklinghausen in 1891.[3] It results from direct effect of parathyroid hormone on bone, causing the conversion of potentially osteogenic cell from osteoblast to osteoclast, with bone resorption exceeding the formation of new osseous tissue. An imbalance of osteoclastic and osteoblastic activity causes bone resorption with fibrous replacement of the marrow and thinning of the cortex. Brown tumors are focal lesion found within these areas of resorption.[4] They most often involve the ribs, clavicle, pelvic girdle and mandible. Mandibular involvement was seen in 4% of patients of hyperparathyroidism.[5] In our case the tumor is involving maxilla, mandible and left knee.

Brown tumors are traditionally associated with primary hyperparathyroidism. Widespread use of dialysis has led to a larger number of patients with secondary hyperparathyroidism. This has resulted in more patients with secondary hyperparathyroidism developing Brown tumor. Grossly they appear as smooth expansile masses causing bone destruction. Histologically there is a dense fibroblastic stroma, focal areas of osteoid, cystic degeneration, hemorrhage, osteoclastic multinucleated giant cells.[6] Hemorrhage and hemosiderin gives the tumor brownish color and thus its name Brown tumor. Brown tumors is difficult to distinguish histologically or radiologically from other giant cell tumors because of its infiltrative nature.[78]

Persistent or large tumors can be removed by surgical method. The destructive nature and tumor progression necessitated surgical removal and was stabilized with external fixation.[8]

It's been reported that Brown tumor could be treated by local radiotherapy or curettage. It is also said that excision of the Brown tumor may be required in case of the large tumor with the tissue destruction.[910]

Reconstruction of mandibular defects represents a challenge to the head and neck reconstructive surgeon. Many methods that are used to reconstruct mandible are alloplastic implants such as bone plates and screws, autogenous bone graft, fibular free flap, scapular free flap, iliac crest, radial forearm free flap, double-flap reconstruction, osteointegrated dental implant. In our case we have used reconstruction plate and screws for the reconstruction of the mandible.[11]