Maxillary Brown Tumor Revealing Primary Hyperparathyroidism: Case Report - Juniper Publishers

 Juniper Publishers- Open Access Journal of Case Studies

Maxillary Brown Tumor Revealing Primary Hyperparathyroidism: Case Report

Authored by K Choukry

Abstract

Hyperparathyroidism is a condition characterized by excessive secretion of parathormone. Brown tumor is one of the complications of primary hyperparathyroidism. The definitive diagnosis is most often difficult. The Brown tumors may be mistaken for giant cell reparative granuloma or giant cell tumors. The histologic appearance of giant cell reparative granuloma is indistinguishable from the brown tumor of hyperparathyroidism. The distinction between the 2 requires correlation with serum calcium and PTH levels, which would be elevated in the latter. We report a case of a 56 year old man with primary hyperparathyroidism revealed by a tumor of the maxilla.

Keywords:Hyperparathyroidism; Brown tumor; Maxillomandibular; Bony erosions; Parathyroid hormone

Introduction

Brown tumor is a benign lesion that rarely developed in the bones of the face, caused by an abnormal metabolism of bone. It is the direct result of the action of parathyroid hormone on the bone structure. It is secondary, in the majority of cases, to primary hyperparathyroidism which results in more than 80% of cases from parathyroid adenoma [1].

Maxillomandibular involvement remains unusual [2]. The Brown tumor cause a progressive painful jugular swelling, It can be locally aggressive without metastatic potential [3].

Brown tumors may be mistaken for giant cell reparative granuloma or giant cell tumors. A definitive diagnosis can be established only when using a combination of clinical, radiographic, and laboratory findings.

Case Report

A 56-year-old man patient without any particular pathological history, was presented to our ENT department with a 6-month history of a slowly growing maxillary mass.

Examination of the oral cavity showed an ulcerated mass, based from the right anterior aspect of the maxilla measuring 3cm. The rest of the somatic examination did not reveal any abnormalities (Figure 1). A facial computed tomographic scan revealed a hyperdense, homogeneous mass measuring 29*35mm involving the right alveolar ridge with bony erosions (Figure 2).

A tumor biopsy was performed, it objectified an aspect of a giant cell tumor. The differential diagnosis arises with a repairing giant cell granuloma and a brown tumor of primary hyperparathyroidism. We perfomed a total excision of the mass as well as the alveolar bone (Figure 3).

Histologic examination of the mass showed an hypercellular mononuclear cell proliferation with evenly distributed, scattered multinucleated giant cells that have the same nuclei as the background mononuclear cells amid a fibrous stroma with vascular spaces (Figure 4).

The diagnosis of brown tumors of the maxilla has been mentioned. On laboratory test, serum calcium level was 11.2mg/dl (normal 8.4-10.7mg/dl), serum albumin level was 5g/dl (normal 3.4-4.8g/dl), serum parathyroid hormone level was 259pg/ ml (normal 7-53pg/ml). The blood test suggested the diagnosis of primary hyperparathyroidism initially expressed by a brown tumor of the maxilla.

The cervical tomodensitometry, confirmed the diagnosis by showing a well-limited, heterodense mass, measuring 13x 12 x15mm, in favor of a left inferior parathyroid adenoma (Figure 5).

Removal of the parathyroid adenoma was performed after 1 month from diagnosis. The pathological report was in favor of a parathyroid adenoma. Two months after the parathyroidectomy, the serum calcium returned to normal. Parathyroid hormone dosage normalized after four months at 38pg/ml.

Discussion

Hyperparathyroidism is discovered incidentally in 75 to 80% of cases during a blood test showing asymptomatic hypercalcemia [4]. It can also be revealed by renal lithiasis or cardiovascular disorders [5]. Brown tumor is a benign lesion developed in the skeletal system, caused by an abnormal metabolism of bone. It is secondary, in the majority of cases, to primary hyperparathyroidism which results in more than 80% of cases from parathyroid adenoma [1].

Primary hyperparathyroidism frequently affects patients over the age of 50 with a predilection for the female sex. The female/ male ratio is 5/2 [6]. Brown tumors may be observed in the pelvis, ribs and femur, Although facial bone involvement has been reported, it is rare [7].

Clinically, the symptoms caused by these lesions depend on the size of the process and its location. they may cause swelling, pathological fracture, and bone pain in the skeletal system [4].

Radiologically, the brown tumor manifests itself by nonspecific osteolysis which can take several aspects. The most common aspect is that of a monogeodic or multilocular bone lysis with unspecified limits causing a blistering of the cortices or even their rupture, the appearance can then suggest malignancy, in particular for destructive lesions.

Cervical ultrasound and CT are ordered to detect damage to the parathyroid glands that causes hyperparathyroidism. CT scan after technetium injection (Tc-99m) is the best way to locate the lesion in the parathyroid glands or ectopic tissues before surgery [5]. The brown tumor is one of the giant cell lesions of the jawbones, which also includes the true giant cell tumor, the central repairing giant cell granuloma, and the aneurysmal bone cyst [4].

Distinguishing between the brown tumor and other giant cell lesions is difficult. Indeed, brown tumors are manifested by non-pathognomonic histological changes that can be observed in true giant cell tumor, restorative granuloma, aneurysm cyst and in fibrous dysplasia [4,8,12].

Hence the need to take into consideration the clinical history, and the results of biological examinations and especially the hormonal status, the demonstration of a disturbance of the phosphocalcic balance makes suspect a hyperparathyroidism, the increase in the level of parathormone allows to establish the diagnosis [4].

The treatment of hyperparathyroidism should be the first step in the management of these patients. Indeed, there is a general consensus which considers that parathyroidectomy is the treatment of choice for primary hyperparathyroidism, however, opinions are divided on the treatment of secondary bone lesions. In fact, the development of brown tumors after parathyroidectomy is variable depending on their composition [9].

Most authors believe that spontaneous regression of these lesions is possible after correction of hyperparathyroidism,with replacement of the bone lesions into normal bone tissue. According to some authors, complete disappearance of the lesion is found six months after treatment for hyperparathyroidism [4,10].

However, some have reported that spontaneous bone regeneration can last for several years before restoring normal facial morphology [3]. In cases where the lesions are extensive or largely destructive, affecting the function of the organ, the tissue damage generated cannot be repaired despite obtaining a normo calcemia. In these situations, or when the lesions persist after treatment for hyperparathyroidism, or when they continue to grow despite hormonal control, Yamazaki recommends curettage of the tumor and its enucleation [2].

For Cicconetti the first step is surgical excision of the tumor in order to stop bone destruction, followed by a second operation, parathyroidectomy, aimed at suppressing the secretion of parathyroid hormone [2].

Conclusion

In conclusion, our case report highlights several differentiating electrocardiographic features of tremor induced artifacts Correct and accurate diagnosis requires careful inspection and interpretation of the ECG in the context of history and clinical examination. This is critically important, to avoid wrong treatment and unnecessary interventions.

 

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