Brown tumour of hyperparathyroidism in the mandible associated with atypical parathyroid adenoma

Abstract

The brown tumour of hyperparathyroidism is a localized bone tumour and an uncommon manifestation of hyperparathyroidism. A 27-year-old woman presented with a mandibular 8 x 10 cm solid mass diagnosed as central giant cell granuloma. Chemical blood analysis revealed increased serum calcium levels of 12.46 mg/dL and the parathyroid hormone level was 124 pg/dL. The patient underwent surgery with removal of a parathyroid mass. Histologically, this parathyroid tissue was seen to be limited by a fibrous capsule with morphological features consistent with atypical parathyroid adenoma. The mandibular tumour has receded and the patient declined further procedures. This is the first case reported of brown tumour as the primary manifestation of an atypical parathyroid adenoma, a lesion that shares some features with parathyroid carcinoma without the unequivocal properties of malignancy.

Aspectos radiológicos e epidemiológicos do granuloma central de células gigantes

“…Three patients presented only one lesion. This demonstrates that not always will the patient with hyperparathyroidism present multiple lesions, and a patient may rarely present more than one lesion without hyperparathyroidism (28,29) .…”

“…CGCGs present a tendency to cross the midline, principally when the lesion is in the mandible (7,9,21,28) . In the present study, we observed that 18.7% of lesions crossed the midline, a result similar to those reported by some authors (5,20,25) .…”

“…Mandible and/or maxilla are sites where giant cell lesions develop in cases of hyperparathyroidism, many times as the first clinical manifestation of this disorder (28,29) . Our sample demonstrated that 80% of patients with hyperparathyroidism were asymptomatic.…”

Loss of Parafibromin Immunoreactivity Is a Distinguishing Feature of Parathyroid Carcinoma

“…We prefer the terminology "equivocal carcinoma" in the research and clinical setting, as gold-standard pathologic criteria does not accommodate a localized parathyroid carcinoma (2,27,40). Considering such patients as having "equivocal carcinomas" is also logical clinically, because they are followed up in a similar fashion as patients with definite parathyroid carcinoma (27,41). Thus, this terminology is more appropriate in view of the potential malignant behavior of these group of tumors, the underrecognition of carcinoma, and the fact that current gold-standard diagnostic criteria of malignancy of invasion or metastasis is limited to advanced disease.…”

Nebenschilddrüsen-Karzinom: Ein seltener Fall mit mandibulärem braunem Tumor

“…Lastly, by far the most important test for diagnosing pHPT is serum level of immunoreactive parathyroid hormone, iPTH [1]. At the time of surgery a high index of suspicion for carcinoma is vital for performing the appropriate surgical procedures, since frozen-section diagnosis of PC is notoriously unreliable [37]. Biopsy is not necessary before definitive surgery [1] and retropharyngeal lymph nodes should be considered as a possible site of metastasis [5].…”