¹Resident in Internal Medicine Training, Department of Internal Medicine, Unidade Local de Saúde do Oeste – Hospital Caldas da Rainha, Caldas da Rainha, Portugal; ORCID: https://orcid.org/0000-0001-9503-7049.

²Resident in Internal Medicine Training, Department of Internal Medicine, Unidade local de Saúde do Alto Alentejo – Hospital de Portalegre, Portalegre, Portugal, ORCID: https://orcid.org/0000-0002-1994-7849.

³Senior Consultant in Internal Medicine, Casa Santa Maria (RNCCI/ERPI), Lisboa, Portugal; ORCID: https://orcid.org/0000-0003-4448-4169

Corresponding Author: Sara Lourenço Tereso, ORCID: https://0000- 0001-9503-7049, Rua Diário de Notícias, 2500-176, Caldas da Rainha, Portugal.

Citation: Sara Tereso, Elisabete Mendes, Carlos Machado e Costa (2026). Expansive Maxillary Brown Tumor in a Patient with Secondary Hyperparathyroidism. Euro J Case Rep Clin Imag. 2026; August, e22,1-3.

Copyrights: © Sara Lourenço Tereso, 2026, et al., This article is licensed under the Creative Commons Attribution-Non Commercial-4.0-International-License-(CCBY-NC) (https://europeanjournalofcasereports.com/blogpage/copyright-policy). Usage and distribution for commercial purposes require written permission.

Image Case Presentation:

A 31-year-old woman from Angola, with chronic kidney disease of unknown aetiology and on a haemodialysis programme since 2015, presented to the emergency department with a progressively enlarging and deforming nasopalatine mass that caused dysphagia and impaired vision in the left eye. Laboratory tests showed negative infectious serologies, Parathyroid Hormone (PTH) of 3462 pg/ml, phosphate 4.1 mg/dl and calcium 9.2 mg/dl. Maxillofacial computed tomography revealed a 78 × 60 × 63 mm mass in the anterosuperior maxillary region, with diffuse alteration of bone density in the context of a disordered phosphocalcic metabolism. Biopsy demonstrated fibrovascular tissue, multinucleated giant cells and haemosiderin deposits, consistent with a brown tumour (Figures 1A, 1B). A diagnosis of brown tumour secondary to secondary hyperparathyroidism was established. The patient underwent parathyroidectomy, with a subsequent decrease in PTH to 348 pg/ml.

Brown tumour is an uncommon osseous manifestation of secondary hyperparathyroidism, typically seen in chronic kidney disease, particularly in patients undergoing haemodialysis [1,2]. Although more frequent in women, craniofacial involvement is rare [1,2]. It is characterised by medullary osteofibrosis and increased focal osteoclastic bone resorption leading to fibrous osteitis [1]. Its expansive behaviour and radiological appearance may mimic malignant lesions [1]. Diagnosis requires clinical, biochemical, radiological and histological correlation, and parathyroidectomy is the treatment of choice to correct the underlying metabolic disorder and promote regression of the lesions [1,3].

Declarations:

Funding: This research received no external funding.

Institutional Review Board Statement: Not applicable.

Informed Consent Statement: Informed consent for publication was obtained from the patient’s legal guardians.

Data Availability Statement: No new data were created or analyzed in this study. Data sharing is not applicable to this article.

Acknowledgments: Not applicable.

Conflicts of Interest: We confirm that there are no conflicts of interest to declare.

References:

1. Shavlokhova V, Goeppert B, Gaida MM, Saravi B, Weichel F, Vollmer A, et al. Mandibular brown tumor secondary to hyperparathyroidism: a case report with five-year follow-up and literature review. Int J Environ Res Public Health. 2021 July,18(14):7370. DOI: 10.3390/ijerph18147370.

2. Lacativa PG, Franco FM, Pimentel JR, Patrício PJ, Filho GMD, Farias ML. Prevalence of radiological findings among cases of severe secondary hyperparathyroidism. Sao Paulo Med J. 2009 May, 127(2):71–77. DOI: 10.1590/s1516-31802009000200020004.

3. Panagopoulos A, Tatani I, Kourea HP, Kokkalis ZT, Panagopoulos K, Megas P. Osteolytic lesions (brown tumors) of primary hyperparathyroidism misdiagnosed as multifocal giant cell tumor of the distal ulna and radius: a case report. J Med Case Rep. 2018 June, 12(1):176. DOI: 10.1186/s13256-018-1723-y.