Department of Radiology, The Catholic University of Korea, College of Medicine, Bucheon St. Mary's Hospital, Sosa-dong, Bucheon, Kyunggi-do, 420-717, Korea.
Skeletal Radiol. 2011 Feb;40(2):205-13. doi: 10.1007/s00256-010-0979-0. Epub 2010 Jun 13.
Brown tumors are focal reactive osteolytic lesions that are encountered in patients with primary or secondary hyperparathyroidism, and these tumors have nonspecific magnetic resonance (MR) imaging findings. However, there are only a few reports on MR imaging of brown tumors. The purpose of this study is to describe the spectrum of MR imaging findings of brown tumors.
The MR imaging features of five patients with clinical and pathological evidence of brown tumor were retrospectively reviewed by two radiologists. The patients had primary hyperparathyroidism, which was confirmed as parathyroid adenoma (n = 2) and parathyroid carcinoma (n = 3). The MR images were evaluated for the presence of solid or cystic portions, the signal intensity of the lesions, the contrast enhancement pattern and the presence of cortex destruction and fluid-fluid levels.
Twelve bone lesions were detected on the MR images of five patients; three lesions in two patients, four lesions in one patient, and one lesion in two patients. The tumor was solid in three lesions, mixed solid and cystic in four, and cystic in five. All the solid lesions were accompanied by mixed lesions. Discontinuity of the cortex and adjacent soft-tissue enhancement were seen in all the solid lesions. Fluid-fluid levels were seen in two cases within the cystic component of the mixed lesions and cystic lesions.
The five patients with brown tumor demonstrated a wide spectrum of MR imaging findings. There are few lesions that are osteolytic on the radiographs and that show a short T2 on MR imaging, such as brown tumor. Multiple cystic or mixed lesions are the expected findings of brown tumors.
棕色瘤是一种局灶性反应性溶骨性病变，发生于原发性或继发性甲状旁腺功能亢进症患者中，此类肿瘤的磁共振成像（MR）表现无特异性。然而，目前仅有少数关于棕色瘤的 MR 成像表现的报道。本研究旨在描述棕色瘤的 MR 成像表现谱。
由 2 位放射科医生对 5 例经临床和病理证实为棕色瘤的患者的 MR 成像特征进行回顾性分析。患者均存在原发性甲状旁腺功能亢进症，经证实为甲状旁腺腺瘤（n=2）和甲状旁腺癌（n=3）。评估了固体或囊性部分的存在、病变的信号强度、对比增强模式以及皮质破坏和液-液水平的存在。
5 例患者的 MR 图像上共发现 12 个骨病变；2 例患者各有 3 个病变，1 例患者有 4 个病变，2 例患者各有 1 个病变。肿瘤在 3 个病变中为实性，在 4 个病变中为混杂实性和囊性，在 5 个病变中为囊性。所有实性病变均伴有混杂性病变。所有实性病变均存在皮质连续性中断和相邻软组织强化。混合性病变囊性成分和囊性病变内可见液-液水平。
5 例棕色瘤患者的 MR 成像表现谱广泛。X 线表现为溶骨性病变且 MR 成像 T2 较短的病变较少，如棕色瘤。多个囊性或混杂性病变是棕色瘤的预期表现。
