Jung Daeyoung, Cho Keun-Tae, Roh Ji Hyeon
Department of Neurosurgery, Ilsan Hospital, Dongguk University, Goyang, Korea.
J Korean Neurosurg Soc. 2013 May;53(5):305-8. doi: 10.3340/jkns.2013.53.5.305. Epub 2013 May 31.
Myositis ossificans (MO) is a benign condition of non-neoplastic heterotopic bone formation in the muscle or soft tissue. Trauma plays a role in the development of MO, thus, non-traumatic MO is very rare. Although MO may occur anywhere in the body, it is rarely seen in the lumbosacral paravertebral muscle (PVM). Herein, we report a case of non-traumatic MO in the lumbosacral PVM. A 42-year-old man with no history of trauma was referred to our hospital for pain in the low back, left buttock, and left thigh. On physical examination, a slightly tender, hard, and fixed mass was palpated in the left lumbosacral PVM. Computed tomography showed a calcified mass within the left lumbosacral PVM. Magnetic resonance imaging (MRI) showed heterogeneous high signal intensity in T1- and T2-weighted image, and no enhancement of the mass was found in the postcontrast T1-weighted MRI. The lack of typical imaging features required an open biopsy, and MO was confirmed. MO should be considered in the differential diagnosis when the imaging findings show a mass involving PVM. When it is difficult to distinguish MO from soft tissue or bone malignancy by radiology, it is necessary to perform a biopsy to confirm the diagnosis.
骨化性肌炎（MO）是一种发生于肌肉或软组织的非肿瘤性异位骨形成的良性病变。创伤在MO的发病过程中起作用，因此，非创伤性MO非常罕见。尽管MO可发生于身体的任何部位，但在腰骶部椎旁肌（PVM）中很少见。在此，我们报告一例腰骶部PVM的非创伤性MO病例。一名无创伤史的42岁男性因腰、左臀部和左大腿疼痛被转诊至我院。体格检查时，在左侧腰骶部PVM可触及一个轻度压痛、坚硬且固定的肿块。计算机断层扫描显示左侧腰骶部PVM内有一个钙化肿块。磁共振成像（MRI）在T1加权像和T2加权像上显示不均匀高信号强度，在增强后T1加权MRI上未发现肿块强化。由于缺乏典型的影像学特征，需要进行开放性活检，最终确诊为MO。当影像学表现显示肿块累及PVM时，鉴别诊断应考虑MO。当通过放射学难以将MO与软组织或骨恶性肿瘤区分开来时，有必要进行活检以确诊。
