Imaging of brown tumours: a pictorial review

Abstract

Brown tumours do not represent neoplastic process, but they are focal bony lesions due to bone remodelling from either primary or secondary hyperparathyroidism. Their incidence is also low. The current literature on brown tumour is mainly in the form of case reports that focus on single affected sites. This pictorial review describes the full imaging workup and pathway of suspected brown tumour in the setting of both primary and secondary hyperparathyroidism. It aims to illustrate the management strategy to aid both clinicians and radiologists in suspected cases of brown tumour. We highlight the complementary roles that different imaging modalities can play in different settings including the importance of parathyroid ultrasound, 99m Tc-sestamibi scintigraphy and SPECT/CT in the localisation of the parathyroid adenoma. We present cases with full clinical and imaging workup in both the acute and chronic setting and scenarios that require exclusion of primary and secondary bone malignancies.

Hiperparatireoidismo Secundário: Correlação Clínica, Laboratorial E Radiológica

“…Os tumores de Brown são característicos do hiperparatireoidismo e constituem lesões cistiformes, destrutivas e localizadas, podendo apresentar diversos tamanhos. Ocorrem, comumente, na mandíbula, pelve e no fêmur (XIE C, et al, 2019;CARDOSO FNC, et al, 2007).…”

“…Esta calcificação, ao acometer a cartilagem articular e resultar em condrocalcinose, apresenta aparência semelhante à calcificação associada ao depósito de cristais de pirofosfato de cálcio di-hidratado, que é visualizada como hiperdensidades pontilhadas e lineares em regiões de fibrocartilagem (XIE C, et al, 2019;AERDEN T, et al, 2018; MIKSANEK J e ANN KR, 2015).…”

When primary hyperparathyroidism comes as good news

“…Osteitis fibrosa cystica is a rare, but pathognomonic manifestation of skeletal involvement in severe pHPT. Radiological features are skull thinning with ‘salt and pepper shape’, diffuse demineralization, bone erosion, phalanges subperiosteal resorption, cysts and, rarely, BT ( 5 , 6 ). Nowadays, due to the introduction of serum Ca determination in routine biochemical tests, primary hyperparathyroidism is generally diagnosed when asymptomatic or mild ( 3 ).…”

“…Bone scintigraphy shows increased uptake at the level of radiological lytic lesions ( Fig. 1A , B , C and D ) ( 5 , 6 ). Grossly, BT appeared as well-circumscribed, hemorrhagic masses eroding the endosteum with consequent cortex remodelling ( 1 ).…”

“…Intensely vascular fibrotic stroma (made by fibroblasts, extravasated red blood cells, macrophages) and multinucleated giant-cells constitute the histological structure ( 1 ). High Ca (Ca) and parathyroid (PTH) hormone levels are crucial to orientate clinical diagnosis ( 1 , 5 , 6 ).

Figure 1 Bone lesions, due to hyperfunctioning parathyroid adenoma, described by different imaging techniques (A, B, C, D, E and F) and corresponding histologic specimens (E, F, G and H).

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