Adipose tissue tumors are the most common soft tissue tumors in both benign and malignant categories. A presumptive diagnosis of the adipose tissue tumors usually can be made based on the imaging findings [5]. However, there are some exceptions. Making differential diagnosis of hibernoma from lipoma-like well-differentiated liposarcoma may be difficult by imaging findings, while the making histological diagnosis is not difficult. Lipoma-like well-differentiated liposarcomas can mimic intramuscular or intermuscular lipomas in radiological as well as histological findings, and they may occasionally cause problems in establishing diagnosis and treatment planning. Although making differential diagnosis of these benign lesions from lipoma-like well-differentiated liposarcomas may be important, it may also be important to make a differential diagnosis between intramuscular lipoma, intermuscular lipoma and hibernoma for appropriate surgical treatment and followup, because differences in recurrence rates among these benign tumors exist. The purpose of this section is to elucidate the differences in imaging features among these adipocytic neoplasms for appropriate treatment planning. The imaging findings of other adipocytic sarcomas are also included.

We carried out an ulnar recession osteotomy procedure in the distal ulna following a dorsal open wedge osteotomy and beta-TCP graft for five patients with wrist pain due to malalignment after fracture of the distal radius. We evaluated the pre- and post-operative (6 months after surgery) parameters for Mayo's wrist score, ulnar variance (UV), inclination of sigmoid notch (SI), inclination of ulnar sheat (UI), palmar tilt (PT) and radial inclination (RI). The clinical outcome showed excellent post-operative function and pain relief in the wrist. Ulnar arched osteotomy with distal radial osteotomy reduced wrist pain and improved joint surface alignment.

Osteoid osteoma usually occurs in the diaphysis or metaphysis of long tubular bones but is rare in flat bones. 3 Dorfman H.D. Czerniak B. Benign osteoblastic tumors. in: Gery L. Bone tumors. Mosby, St Louis1998: 85-104 Google Scholar Osteoid osteoma, in some instances, occurs adjacent to a large joint such as the knee and induces a reactive synovitis. 2 Brabants K. Geens S. Damme B. Subperiosteal juxta-articular osteoid osteoma. J Bone Joint Surg Br. 1986; 68: 320-324 PubMed Google Scholar We report a very rare case of osteoid osteoma located in the scapula associated with synovitis of the shoulder joint.

ObjectiveThe objective of this study was to clarify the effects of mechanical stress on chondrocytes cultured in a tube. Centrifugal pressure was applied to chondrocytes cultured in a tube for 28 days, and the effect of this stress was evaluated using a molecular biological method.DesignArticular cartilage was harvested from a rabbit. A cell suspension was then prepared, and transferred in 1 ml aliquots to polypropylene tubes. After 48 h of incubation, centrifugal pressure (6.9 MPa) was applied every 24 h. Changes in morphology, expression of messenger RNA (mRNA) for insulin-like growth factor-I (IGF-I) and type II collagen, cell number, wet weight and protein concentration were evaluated.ResultsMicroscopically, formation of chondrocyte clusters was seen in the cultures subjected to stress. Ultrastructurally, collagen fibers were seen to run parallel to the cytoplasmic surface of the stressed chondrocytes. The peak of IGF-I mRNA expression was seen on day 5, whereas type II collagen mRNA expression peaked on day 14. Cell number, wet weight and protein concentration were significantly increased in the stressed cultures.ConclusionsThese results suggest that mechanical stress might affect the arrangement of collagen fibers and the IGF-I activity of chondrocytes cultured in a tube, thus influencing chondrocyte proliferation and increasing the volume of the extracellular matrix. Furthermore, mechanical stress may also affect the metabolism of articular cartilage in vitro.

A recurrence of a juxtacortical chondroma of the finger after marginal excision prompted us to review the treatment of this condition. Although the recommended treatment is simple curettage or marginal excision, the reported recurrence rate is significantly higher for lesions in the hand than those in other locations and recurrences only occurred in patients who had local treatments which did not include excision of the adjacent bone cortex.We report five patients with juxtacortical chondroma of the fingers. The first patient underwent marginal excision without resection of the underlying bone cortex. The other four patients underwent intralesional, marginal or wide excisions of tumour with resection of the bone cortex underlying the lesion. Recurrence was only seen in the patient who did not undergo resection of the bone cortex. Resection of the underlying bone cortex after excision of this tumour may be advisable for the treatment of this tumour in the hand to reduce the rate of recurrence.

Adhesion between the tendon and tendon sheath after primary flexor tendon repair is seen frequently, and postoperative finger function is occasionally unsatisfactory. A reduction of the friction may facilitate tendon mobilization, which in turn may reduce the risk of the adhesion and restriction of range of motion. We considered the possibility of utilizing the hyaluronic acid (HA) as a lubricant. To evaluate the effect of HA, the gliding resistance between the canine flexor digitorum profundus tendon repaired by a modified Kessler suture technique with running epitendinous suture and the annular pulley located on the proximal phalanx (corresponding to the A2 pulley in humans) was evaluated and compared before and after administration of HA. The HA solution measurement groups were identified as follows; intact tendon as a control; repaired tendon; tendon soaked in 0.1, 1, and 10mg/ml HA. The resistance increased after repairing, then it decreased after soaking in 10mg/ml HA solution. The results of this study revealed that HA diminishes the excursion resistance after flexor tendon repair. We believe that some style of administration of the HA might reduce the excursion resistance and prevent adhesion until the synovial surface is fully developed.

The excursion resistance between the tendon and pulley is an important factor contributing to the limitation of function after surgery to the hand. The administration of hyaluronic acid (HA) in the early rehabilitation after tendon grafting may help to prevent adhesions. We evaluated changes in the excursion resistance between potential sources of flexor tendon grafts and the annular pulley in a canine model after administration of HA. The intrasynovial and extrasynovial tendons were soaked in 10 mg/ml of HA for five minutes. The excursion resistance between these tendons and the annular pulley of an intact proximal phalanx and that of the same tendons of the opposite foot without administration of HA were evaluated. The tendon of flexor digitorum profundus of the second toe without administration of HA was used as a control. The gliding resistance of canine tendons was significantly decreased after the administration of HA especially in the extrasynovial tendons. Our findings suggest that the administration of HA may improve the gliding function of a flexor tendon graft.

OBJECTIVE:To clarify the clinical and magnetic resonance (MR) imaging features of a rare condition of metastasis of carcinoma to skeletal muscle.METHOD:Clinicopathological findings for 12 patients (10 male, two female, age range 48-89 years, mean age 68 years) with skeletal muscle metastases of carcinomas were reviewed retrospectively.RESULTS:In nine of the 12 patients the skeletal muscle metastasis was presented as "painful mass". The lung was found to be the most common primary source, accounting for 33% of the cases, and the lower extremity was the most common metastatic site, accounting for 67% of the current series. Diagnosis was made by biopsy in all cases. Overall, MR images were not specific, but on the gadolinium-DTPA enhanced MR images, extensive peritumoral enhancement associated with central necrosis was found in 11 of the 12 patients (92%). Seven patients died within 2-19 months (average: 9 months) after the detection of the skeletal muscle metastasis, among whom only one patient was continuously disease free for 92 months after wide excision of the metastatic lesion.CONCLUSION:Skeletal muscle metastasis is often presented as a painful mass in patients with known primary carcinoma. For diagnosis, needle biopsy is mandatory. However, a painful mass with an extensive peritumoral enhancement should be highly suspected to represent carcinoma metastasis to skeletal muscles. In selected patients, wide excision with combined chemotherapy could yield unexpectedly good results.

Study Design. A case of the solid variant of aneurysmal bone cyst affecting the posterior component of the fourth cervical vertebra is reported. Imaging studies showed an expansile destructive lesion. After curettage, autologous iliac bone grafting with posterior fusion was performed. There was no sign of local recurrence 2 years after surgery. Objectives. To emphasize the occurrence of the solid variant of aneurysmal bone cyst in the cervical spine. Summary of Background Data. The solid variant of aneurysmal bone cyst is rare, and only 12 cases occurring in the vertebrae, including 3 in the cervical vertebrae, have been reported. The condition is difficult to diagnose radiologically before biopsy or surgery. Methods. A 9-year-old girl presented with pain in the nape of the neck without any neurologic deficit. She was found to have the solid variant of aneurysmal bone cyst in the posterior component of the fourth cervical vertebra, which had destroyed the lamina and spinous process. Part of the posterior aspect of the C4 vertebral body was also involved. Curettage of the lesion was performed, and the defect in the posterior component of the vertebra was reconstructed using an autologous iliac bone graft with posterior fusion using a halo vest. Results. Magnetic resonance imaging disclosed a homogeneous low intensity mass at the lamina, spinous process, and vertebral body of C4 on T1-weighted images. The mass showed heterogeneous high signal intensity on Gd-enhanced images. Histologically, the resected specimen showed predominant fibroblastic proliferation, with minor foci of reactive osteoid formation and an area of osteoclast-like giant cells. Neither cellular atypia nor mitotic figures were evident. There was no sign of local recurrence 2 years after surgery. Conclusions. The solid variant of aneurysmal bone cyst should be included in the differential diagnosis of any lytic expansile lesion of the spine, even though it is a destructive lesion. Gd-enhanced magnetic resonance imaging may be helpful for distinguishing the solid variantfrom conventional aneurysmal bone cyst.

Study Design. A chondroblastoma of the posterior component of the seventh cervical vertebra with tetraparesis was reported. Imaging studies showed an expansile destructive lesion with mineralization. Objectives. To emphasize the occurrence of tetraparesis caused by chondroblastoma in the cervical spine. Summary of Background Data. Chondroblastoma is a rare benign neoplasm of the bone. Only eight cases of chondroblastoma occurring in the vertebra are reported in the literature, including five in the cervical vertebrae. However, there was no reported case of tetraparesis in the literature. Methods. A 19-year-old man had a tetraparesis caused by chondroblastoma of the posterior component of the seventh cervical vertebra, which invaded the vertebral body with an extraosseous involvement. Imaging studies showed an expansile destructive lesion with mineralization. Curettage of the lesion was performed from both anterior and posterior approaches. The defect of the vertebral body was reconstructed by autologous iliac bone graft with posterior fusion using the Luque instrumentation system. Results. Histologically, the tumor cells were forming cartilage with round or oval nuclei, which often were indented or had a longitudinal groove. There was no sign of local recurrence, and the neurologic deficit had fully recovered 2 years and 3 months after surgery. Conclusions. Chondroblastoma should be included in the differential diagnosis of lytic expansile destructive lesion of the spine, although there is an extraosseous involvement. Prompt adequate surgery should be performed as soon as possible after establishment of the correct histologic diagnosis to restore the neurologic deficit.

The antitumor effects of piroxicam, a non-steroidal anti-inflammatory drug, on sarcoma 180 cells under ultrasonic irradiation were examined in a mouse air pouch model. When piroxicam was added to sarcoma 180 suspension under ultrasound irradiation (2 MHz, 10 W, 120 s), the mortality rate of tumor cells immediately after the irradiation and the survival rate of mice were significantly higher than those when ultrasound alone was applied, and these effects of piroxicam were dose-dependent. When D-mannitol was used with piroxicam, the mortality rate of the tumors cells after the irradiation was comparable with that when piroxicam alone was applied, but when L-histidine was used concurrently, the antitumor effect was significantly lower than that when piroxicam alone was applied. Histological examinations one week after the ultrasound irradiation in the presence of piroxicam showed sparse tumor tissue in the air pouch and normal appearance of the air pouch and surrounding tissue. The findings suggest that piroxicam enhances the anti-tumor effects of ultrasound in vivo by increasing the production of singlet oxygen without damage to tissue surrounding the tumor.

Revascularization of Avascular Necrosis of the Capitate BoneHanae Murakami1, Jun Nishida1, Shigeru Ehara2, Katsuro Furumachi1 and Tadashi Shimamura1Audio Available | Share

Macrodystrophia lipomatosa is a congenital macrodactyly characterized by proliferation of all mesenchymal components, particularly fibroadipose tissue. We report imaging features of two such patients. MR imaging and CT scanning demonstrated proliferation of fatty tissue in the territory of the median nerve in the hands and forearms, characteristic of macrodystrophia lipomatosa.

Objective. Pasteurized autogenous bone graft sterilized at a low temperature (60°C) is one option for reconstruction after resection of bone and soft tissue tumors. The purpose of this investigation was to assess the normal and abnormal radiographic and scintigraphic findings of pasteurized intercalary autogenous bone graft after resection of bone and soft tissue sarcomas.

Low-grade intraosseous osteosarcoma is an uncommon form of bone cancer. It is occasionally difficult to recognize as a malignant tumor and is commonly misdiagnosed as a benign fibrous lesion. We retrospectively studied the records of 8 patients with low-grade intraosseous osteosarcoma in the files of the Tohoku Musculoskeletal Tumor Society in Japan. All tumors arose in the lower limb. The most common symptom was pain, with a duration exceeding 2 years in 4 patients. Radiologic findings, including those at magnetic resonance imaging (MRI), suggested malignancy in 5 lesions, whereas 3 were diagnosed as benign. Two patients initially presented with pathological fracture. The initial pathological diagnosis was malignant in 5 patients and benign in 3. All eight tumors were grade 1 in Broders' classification. The tumor showed a permeative pattern in all eight cases, but this pattern could not be confirmed in the multiple tiny fragments obtained as biopsy specimens in 3 cases. The number of silver-staining nucleolar organizer regions (AgNOR) per nucleus and MIB-1-positive rate were significantly higher in low-grade intraosseous osteosarcoma than in fibrous dysplasia, offering an advantage in differential diagnosis. Three patients (38%) developed high-grade sarcoma at the site of local recurrence after multiple intralesional excisions, and one of them died of the disease. The other 5 patients had a good clinical course after surgery with a wide margin. These findings indicate that preoperative diagnosis with radiologic investigation, including magnetic resonance (MR) imaging and histologic examination of biopsy specimens is essential in preparation for surgery with a wide margin, assuring a good clinical course, and the results of AgNOR and immunohistochemical MIB-1 staining might be helpful in differentiating low-grade intraosseous osteosarcoma from fibrous dysplasia.

A human cadaver tendon sheath model was used to study the differences in excursion resistance of tendons that might be considered as sources of clinical tendon grafts. The flexor digitorum profundus and superficialis tendons, the extensor indicis proprius tendon used in its normal proximal-distal orientation, the extensor indicis proprius tendon used in a reversed distal-proximal orientation, and the palmaris longus tendon were studied in 7 fingers. The intrasynovial tendons (the flexor digitorum profundus and superficialis tendons and the reversed extensor indicis proprius tendon) produced less excursion resistance (p < .05) than the extrasynovial tendons (the normally oriented extensor indicis proprius tendon and the palmaris longus tendon). In contrast to studies measuring resistance against a single pulley, resistance within a complete tendon sheath may be affected by contact with other structures, particularly in joint extension.

Ten cadaver digits were used to evaluate excursion resistance between a tendon and pulley after completing 4 methods of pulley reconstruction (Bunnell's, Kleinert's, Lister's, and Karev's techniques). Five tissues (palmaris longus tendon, extensor digitorum tendon, flexor digitorum superficialis tendon, extensor retinaculum, and volar plate) were used to reconstruct the A2 pulley. Intrasynovial tissue sources (extensor retinaculum, volar plate, and flexor digitorum superficialis tendon) produced less excursion resistance than extrasynovial tissue sources (extensor digitorum tendon and palmaris longus tendon). The models using the extensor retinaculum and volar plate as reconstructive materials produced less excursion resistance than the normal A2 pulley, whereas the models using the palmaris longus tendon produced the highest excursion resistance. Bunnell's technique of pulley reconstruction produced less excursion resistance than Kleinert's technique with all 3 tissues tested. The results of the in vitro study of excursion resistance between the tendon and reconstructed pulley demonstrated that Lister's technique of pulley reconstruction using the extensor retinaculum produced the least resistance to tendon gliding.