Soft tissue osteochondroma

Three cases of benign soft tissue osteochondroma, a lesion of uncertain pathogenesis, are reported. Two cases were located in the subcutaneous tissues beneath the calcaneus. The other was located in the soft tissues near the left ankle joint. The diagnosis of soft tissue osteochondroma should be considered when a well-defined osseous mass is located in the soft tissues. the differential diagnosis includes myositis ossificans, tumoral calcinosis, synovial chondromatosis, and soft tissue osteosarcoma.     

Non-traumatic myositis ossificans. Ultrasonic and x-ray computed tomographic aspects. Apropos of a case

Radiology in a patient with non-traumatic myositis ossificans produced standard images suggestive of juxta-cortical osteosarcoma, the peripheral form of a chondrosarcoma or a synovial sarcoma. Ultrasound failed to provide a conclusive diagnosis, and a scan was the only means of suggesting the benign nature of the lesion by demonstrating integrity of bony cortex and characteristic disposition of calcifications.     

Unusual Presentation of Widely Metastatic Extraskeletal Osteosarcoma: Case Report

Extraskeletal osteosarcoma is a highly aggressive malignant osteoid forming mesenchymal neoplasm arising from soft tissues which accounts for 1% of all soft tissue sarcomas. We report the case of a 46-year-old female with no significant past medical history presenting to an emergency department with a right lateral thigh mass following minor trauma. She was eventually found to have high grade extraskeletal osteosarcoma with rapid progression of disease resulting in patient demise. Differentiation of these lesions from alternative processes relies on specific imaging and pathologic features. Differential diagnoses include both benign and malignant etiologies such as myositis ossificans, soft tissue hemangiomas, and other malignant soft tissue neoplasms such as epithelial and synovial sarcoma.     

Magnetic resonance imaging of myositis ossificans: analysis of seven cases

Myositis ossificans typically presents as soft tissue swelling with progressive ossification on radiographs. Since magnetic resonance imaging (MRI) is commonly used to evaluate soft tissue masses, we analyzed eight MR examinations in seven patients with myositis ossificans to determine if typical patterns were present. One acute lesion had homogeneous intermediate signal intensity on T1-weighted images and high signal intensity on T2-weighted images. Two subacute lesions had low signal intensity margins with slightly increased signal intensity centers on T1-weighted images and very high signal intensity on T2-weighted images. Five chronic lesions had two different patterns. All five were well-defined with low signal intensity borders. Three had signal intensity patterns characteristic of fat on T1-weighted and T2-weighted images. The other two lesions had intermediate signal intensity on T1-weighted images and slightly increased signal intensity on T2-weighted images.We conclude that typical MR appearances of myositis ossificans do exist. A low signal intensity rim is a common finding. However, these patterns are not unique to myositis ossificans and resemble those that have been reported in other lesions. It is important to be aware of the spectrum of MR findings of myositis ossificans when considering the differential diagnosis of a soft tissue mass.     

Benign tumefactive soft tissue extension from Paget’s disease of bone simulating malignancy

Osteosarcoma is a frequently fatal complication of Paget’s disease of bone typically manifesting radiographically as a lytic lesion with soft tissue extension. A clinically worrisome, but benign manifestation of Paget’s disease simulating malignancy because of an extraosseous mass is reported. Received: 19 January 2000 Revision requested: 18 August 2000 Revision received: 31 October 2000 Accepted: 3 November 2000     

Soft tissue aneurysmal bone cyst

A soft tissue aneurysmal bone cyst located in the right gluteus medius of a 21-year-old man is reported. On conventional radiography, the lesion demonstrated a spherically trabeculated mass with a calcific rim. On CT scan, it showed a well-organized peripheral calcification resembling a myositis ossificans. On MRI, it presented as a multilocular, cystic lesion with fluid-fluid levels. The lesion had no solid components except for intralesional septa. Although findings on imaging and histology were identical to those described in classical aneurysmal bone cyst, diagnosis was delayed because of lack of knowledge of this entity and its resemblance to the more familiar post-traumatic heterotopic ossification (myositis ossificans).     

Cervical myositis ossificans traumatica: a rare location

An unusual case of myositis ossificans traumatica lesion located in the paraspinal region is reported. Despite the contiguity of the lesion with the cervical vertebrae and ominous appearance of the biopsy material, the history of antecedent trauma and computed tomography findings allowed preoperative accurate diagnosis. To our knowledge, myositis ossificans traumatica located in the cervical paraspinal region is very rare. Received: 9 March 1998; Revision received: 22 May 1998; Accepted: 12 June 1998     

Postradiation sarcomas of the pelvis after treatment for uterine cervical cancer: review of the CT and MR findings of five cases

Objective. To characterize the radiologic features of postradiation sarcomas arising in the pelvic bones following treatment for uterine cervical carcinoma. Design and patients. Five patients who developed postradiation sarcomas in the pelvic bones following radiation therapy for carcinoma of the uterine cervix within the irradiated field were evaluated. Pelvic radiographs, computed tomography (CT) and magnetic resonance (MR) imaging were undertaken in all patients. Histologic confirmation of the tumor type was obtained. Results. Three patients whose tumors were characterized as an osteosarcoma, an angiosarcoma and a malignant fibrous histiocytoma (MFH) showed a large round or oval mass mainly in the sacroiliac joint which extended into the posterior gluteal soft tissues. In a fourth patient an osteosarcoma developed in the central ilium extending widely into the soft tissues both anteriorly and posteriorly, with calcified areas within the extraosseous mass. The fifth patient had a MFH which showed osteolytic destruction of the cortex of the acetabulum, and minimal soft tissue extension. There were no specific features or signal intensity changes on MR imaging to differentiate these cases from primary sarcomas. Conclusion. Postradiation sarcoma must be considered in patients with uterine carcinoma when a soft tissue mass is seen in the previously irradiated field, especially if the mass is posterior to the sacroiliac joint and the latent period is more than 5 years. Received: 3 May 2000 Revision requested: 14 July 2000 Revision received: 28 July 2000 Accepted: 20 November 2000     

Myositis ossificans with Ga-67 citrate positivity

A 16 year-old boy presented with a firm mass within the left thigh. Ga-6 7 citrate and bone scintigraphy revealed soft tissue radiotracer accumulation within the mass lesion. Radiographs and xerography of the left thigh revealed calcification within the soft tissue mass typical of myositis ossificans. The patient's clinical course was uneventful.     

骨化性肌炎的临床和MRI表现分析

目的:分析骨化性肌炎的临床和MRI表现特点,以提高其诊断和鉴别诊断的能力。方法:对16例经手术或穿刺病理证实为骨化性肌炎患者的临床和MR检查图像进行回顾性分析。结果:外伤后四肢痛性软组织肿块是其主要临床表现,T2WI上见有团块和分叶状不均匀信号、边缘有低信号带形成的软组织肿块,周围有显著的水肿带是其特征性的MRI表现。结论:骨化性肌炎临床上多有外伤史,MRI表现具有一定的特征性,提高对其MR表现的认识有助于诊断和鉴别诊断,避免不必要的手术。     

局限性骨化性肌炎的X线、CT表现

目的：探讨局限性骨化性肌炎的X线平片和CT表现,提高影像诊断水平。方法：回顾性分析19例经病理或随访证实局限性骨化性肌炎患者的X线、CT表现,其中19例均行X线平片检查,13例行CT检查。结果：X线表现为软组织内条片状或分层状骨化影;CT表现：早期（急性水肿期）局部肌肉水肿,无明确骨化成分,受累骨可出现轻微骨膜增生,中期（增殖肿块期）表现为分层状＂蛋壳＂样骨化,病灶中心呈软组织密度,晚期（骨化修复期）病灶局限,边界清楚,周围肌肉水肿消失,影像学表现为离心性分布的骨化团块。结论：局限性骨化性肌炎早期影像学表现缺乏特征性,容易误诊,中晚期分层状＂蛋壳＂样骨化对本病诊断有重要价值。     

Myositis ossificans of psoas muscle: magnetic resonance imaging findings

Myositis ossificans is a benign, localized, self-limiting ossifying soft tissue mass with unknown pathogenesis. It may be confused with a malignant tumor of bone or soft tissues, especially in the early stages of the disease. In this report, we present a case of myositis ossificans affecting unilateral psoas muscle, which to our knowledge is a very uncommon location. There was no history of trauma. We describe the imaging findings and clues to early diagnosis of myositis ossificans.     

Proliferative myositis in a child

A case of proliferative myositis in the lumbar paraspinal muscles in a 14-year-old boy is presented. Imaging investigations including plain radiograph, ultrasound, computed tomography (CT), magnetic resonance imaging (MRI), bone scan and positron emission tomography (PET) were suggestive of an inflammatory process such as myositis ossificans. The diagnosis was made by incisional biopsy. More pronounced edema, more muscle fiber necrosis and a higher cellularity were found compared to adult cases. The karyotype of the lesion was normal. Clinically, the mass disappeared spontaneously. After 24 months, asymptomatic bridging ossification between the third and fourth lumbar vertebrae was noted. Received: 18 February 1999 Revision requested: 29 March 1999 Revision received: 23 August 1999 Accepted: 24 August 1999     

Immunoglobulin D myeloma presenting as an extraosseous soft tissue tumor

We report a 69-year-old man who suffered an extraosseous tumor of immunoglobulin D myeloma (lambda type) in the shoulder girdle, mimicking a primary soft tissue sarcoma. The tumor was isointense with adjacent muscle on T1-weighted MR images, and hyperintense on T2-weighted images. No continuity with the neighboring bone was noted. After administration of gadolinium, the central part of the tumor showed marked contrast enhancement. Although the tumor showed a complete response to the initial chemotherapy, the patient died of the disease 31 months after its initial manifestation. Several bone marrow aspirations and biopsies of the ilium and sternum had shown no increase in plasma cells (range 0.6–1.2%) until the disease became advanced 19 months after its initial manifestation. Received: 1 September 2000 Revision requested: 9 October 2000 Revision received: 11 November 2000 Accepted: 15 November 2000     

Florid reactive periostitis and bizarre parosteal osteochondromatous proliferation: pre-biopsy imaging evolution, treatment and outcome

Objective. To report on the imaging evolution of florid reactive periostitis (FRP) and bizarre parosteal osteochondromatous proliferation (BPOP) of the phalanges of the hands from prospective diagnosis to operation and on postsurgical outcome. Design and patients. Three patients (2 female, 1 male; age range 11–34 years) presented with a swollen digit of the hand. Following presumptive radiographic diagnosis of FRP, they were closely observed both clinically and radiographically until operation. All three patients had radiographs of the involved digit, and one patient had an MR imaging examination. The interval between presumptive diagnosis and operation ranged from 2 to 8 months. Following operation, the patients have been clinically followed for 9–13 months (mean 10 months). Results. In each of the patients, maturing of periosteal reaction without bone destruction was observed within 1–2 weeks of the presumptive diagnosis of FRP. Periosteal reaction was initially minimal in relation to the extent of soft tissue swelling and subsequently became more florid. In one patient, the lesion ossified, became adherent to the phalanx, and had an ”osteochondromatous” appearance. In another patient, periosteal reaction was seen on both sides of the phalanx with an intact phalanx. In the sole patient who had MR imaging, edema was seen in the phalanx distal to the symptomatic site and the metacarpal proximal to the symptomatic site. Conclusions. Close clinical and radiographic correlation permits an accurate pre-biopsy diagnosis of FRP. The first follow-up radiograph taken within 2 weeks usually provides reassurance of the accuracy of the diagnosis. FRP may progress to BPOP. Arbitrary antibiotic treatment can be avoided, and a planned surgical approach can be adopted. Received: 21 August 2000 Revision requested: 8 December 2000 Revision received: 26 December 2000 Accepted: 26 December 2000     

Diagnostic imaging of tibial periosteal ganglion

A case of a soft tissue tumor situated in the anterior surface of the proximal end of the tibia in an adult patient is demonstrated by conventional radiographs, CT, and MRI. The lesion was well defined with respect to the adjacent soft tissue. The CT exam showed a soft tissue mass with external cortical erosion and thick spicules by periosteal reaction. On T1-weighted images the mass was homogeneous and of low signal intensity, whereas on T2-weighted images it showed a high signal intensity, with some septa in the mass. The differential considerations include a periosteal chondroma, a lipoma, a subperiosteal hematoma, an inflammatory process, a giant cell tumor of tendon sheath, and a parosteal osteosarcoma. The CT and MR features of these entities are reviewed as an aid in differential diagnosis of the periosteal ganglion. Received 24 July 1995; Revision received 19 February 1996; Accepted 21 February 1996     

Spinal epidural hemangioma related to pregnancy

We report the case of a 39-year-old woman with adolescent idiopathic scoliosis presenting with myelopathy secondary to a spinal epidural hemangioma. MRI showed an epidural soft tissue mass within the spinal canal between T5 and T9 with severe spinal cord compression. Symptoms had a temporal relationship to her pregnancy. Surgical removal of the epidural hemangioma rapidly relieved her symptoms and neurologic deficits. Follow-up examination 2 years later demonstrated normal motor and sensory function, without any neurologic sequelae or progression of deformity. Received: 16 June 2000 Revision requested: 2 June 2000 Revision received: 13 September 2000 Accepted: 25 September 2000     

Pigmented villonodular synovitis of the hip presenting as a retroperitoneal mass

We present an unusual case of diffuse pigmented villonodular synovitis (PVNS) of the hip presenting as a large retroperitoneal mass in an asymptomatic 39-year-old man. Initial imaging characteristics and findings on core needle biopsy suggested soft tissue sarcoma. However, incisional biopsy showed findings of PVNS. The patient underwent radical synovectomy and total joint replacement, with no change in the large retroperitoneal component after 15 months of follow-up. Received: 15 June 2000 Revision requested: 8 September 2000 Revision received: 14 March 2001 Accepted: 15 March 2001     

Localized interstitial calcinosis (author's transl)]

Case report of an unusual case of soft tissue calcification in the lower leg of a 50 year old patient examined for compensation problems for a gunshot fracture suffered in World War II. The differential diagnosis "localized interstitial calcinosis", "myositis ossificans" and "myositis ossificans progressiva" is being discussed.