A brown tumor is a rare, non-neoplastic pseudotumoral lesion that develops secondary to primary, secondary, or tertiary hyperparathyroidism. It arises from excessive bone remodeling caused by increased osteoclastic activity under elevated parathyroid hormone (PTH) levels. The peripheral form occurring in soft tissues adjacent to the alveolar bone is exceptionally rare and typically involves the gingiva. Clinically, it may strongly resemble more common lesions such as peripheral giant cell granuloma (PGCG) [1].

Accurate diagnosis is essential because treatment differs substantially: PGCG typically requires local surgical excision and removal of irritative factors, whereas brown tumors necessitate systemic management of the underlying hyperparathyroidism.

This paper presents a clinical case highlighting the diagnostic difficulty of peripheral brown tumors and provides a literature-based synthesis of their key features and management.

A 38-year-old woman presented with a progressively enlarging vestibular gingival swelling in the right maxillary region over a four-month period.

Intraoral examination revealed a firm, painless, sessile, reddish mass on the alveolar crest. (Figure 1Figure 1).

Panoramic radiography showed a localized osteolytic zone underlying the lesion (Figure 2Figure 2).

The lesion was surgically excised and submitted for histopathological analysis (Figure 3Figure 3).

Microscopically, the specimen showed a lobulated architecture with numerous clustered multinucleated giant cells, fibroblasts, and histiocytes in a richly vascularized stroma (Figure 4Figure 4).

These features were compatible with a giant cell lesion such as PGCG or brown tumor. Subsequent laboratory tests revealed markedly elevated PTH levels, which supported the diagnosis of a peripheral brown tumor.The patient was referred to endocrinology for further evaluation and management of hyperparathyroidism.

The patient was closely monitored through regular clinical follow-up visits. Healing progressed uneventfully, with satisfactory soft tissue repair observed one week after surgery (Figure 5Figure 5). At the one-year follow-up, the surgical site demonstrated complete mucosal healing with no clinical evidence of recurrence (Figure 6Figure 6). In parallel, the patient remained under endocrinological care for the management of the underlying hyperparathyroidism. This favorable outcome highlights the importance of combining local surgical treatment with appropriate systemic management and long-term follow-up to minimize the risk of recurrence.

Figure 1. Intraoral view illustrating the lesion.

Figure 2.Panoramic radiograph revealing marked osteolysis adjacent to the lesion in the right maxillary alveolar ridge.

Figure 3.Macroscopic view of the excised lesion (2 × 3 cm).

Figure 4.H&E-stained histological section showing multinucleated giant cells within a fibroblastic-histiocytic stroma.

Figure 5.Intraoral view showing healing after 7 days.

Figure 6.Follow-up photograph after 1 year.

Peripheral giant cell lesions of the jaws mainly include PGCG and peripheral brown tumor. Their clinical, radiographic, and histologic overlap makes distinguishing them based on morphology alone difficult. PGCG is a benign reactive lesion generally resulting from chronic irritation or trauma [2]. In contrast, brown tumors represent a skeletal manifestation of hyperparathyroidism and reflect systemic metabolic disturbance rather than a local reactive process [3].

Both lesions contain multinucleated giant cells, hemosiderin deposits, and a fibrovascular background. Thus, systemic assessment is essential: elevated serum PTH strongly suggests a brown tumor [4], whereas normal values favor PGCG.

Peripheral brown tumors most often occur in women over 30 years of age and are commonly located in the edentulous anterior mandible, though maxillary involvement occurs [5]. Clinically, they present as painless, red-to-purple soft tissue masses that may be sessile or pedunculated. Radiographs may reveal underlying bone resorption. Histologically, brown tumors contain abundant multinucleated giant cells, hemosiderin-laden macrophages, and a rich vascular network, giving their characteristic brownish appearance [3].

Management requires both surgical excision and systemic correction of hyperparathyroidism. Parathyroidectomy is indicated in primary hyperparathyroidism, while medical management is used for secondary or tertiary forms, often associated with chronic kidney disease. Recurrence rates remain low (5% - 11%) if both local and systemic factors are appropriately addressed. Long-term follow-up is essential.

These studies underline the diagnostic ambiguity between PGCG and peripheral brown tumors. Identifying a systemic brown tumor is crucial, as delayed diagnosis

Table 1.Summary of key literature on peripheral brown tumor and PGCG.

Table 2. Clinical cases of peripheral brown tumors reported in the literature.

may postpone necessary endocrinological management. A multidisciplinary approach is strongly advised. Together, these studies underline the diagnostic ambiguity between PGCG and peripheral brown tumors. Identifying a systemic brown tumor is crucial, as delayed diagnosis may postpone necessary endocrinological management. A multidisciplinary approach is strongly advised (Table 1, Table 2).

Peripheral brown tumors are rare but clinically important lesions that closely mimic common reactive entities such as PGCG. Because clinical and histological features overlap, a thorough systemic evaluation including serum PTH measurement is essential for correct diagnosis. Treatment requires both surgical excision and management of the underlying hyperparathyroidism. Early identification and coordinated multidisciplinary care are key to preventing recurrence and systemic complications [4].