Yong-Koo Kang

Extra-articular soft tissue ganglion cyst around the knee: focus on the associated findings.

The aim of this study was to evaluate MR imaging findings of the associated findings in surrounding tissues of the extra-articular soft tissue ganglion cysts around the knee. We retrospectively reviewed MR images of 30 patients who had surgically confirmed extra-articular soft tissue ganglion cysts around the knee with focus on the associated findings in surrounding tissues, such as muscle, subcutaneous fat, bone, and nerve. The most common associated finding was the visualization of channel between ganglion cyst and the joint, which was demonstrated in 20 cases (continuous type in 12 cases and discontinuous type in 8 cases). Other associated findings were seen in 15 cases; pericystic edema (n=9), bony remodelling (n=3), and nerve involvement (n=3). The bony remodelling involved the proximal metaphysis of tibia in all 3 cases. Two patients with nerve involvement had deep peroneal nerve in subacute phase and one involved common peroneal nerve in chronic phase. The MR imaging is a useful imaging modality to evaluate the associated findings in extra-articular soft tissue ganglion cysts around the knee. The evaluation of these associated findings is helpful for the differentiation of ganglion cysts from other cystic lesions around the knee.

Dysplasia epiphysealis hemimelica: radiographic and magnetic resonance imaging features and clinical outcome of complete and incomplete resection

ObjectivesThe objectives of this communication were to discuss radiographic and magnetic resonance (MR) imaging manifestations and clinical outcome after complete and incomplete resection of the mass of dysplasia epiphysealis hemimelica (DEH).Materials and methodsClinical records, radiographs, and MR images of eight patients with DEH were retrospectively examined. Six patients were treated by complete excision of the lesional mass, and two patients were treated by incomplete resection at our University Hospitals during the period from 1980 to 2006.ResultsWe found that, unlike in osteochondroma, DEH was radiographically not clearly separable from the underlying or host bone with preserved cortical bone and marrow continuity. The finding in the talus distinguished DEH from (osteochondroma-like) parosteal osteosarcoma, in which a radiolucent demarcation line clearly separated the tumor from the host bone. The DEH mass had a well-defined low to intermediate signal intensity on T1-weighted images and an intermediate to high signal intensity on T2-weighted images, with irregularity of the articular surface. Simple excision was performed in all patients. The excision was complete in six patients and incomplete in two patients whose lesions was juxta-articular in the ankle and articular in the knee, respectively. The residual mass slowly absorbed and vanished, resulting in mild flaring of the affected portion of the epiphysis. No local recurrence or complication was seen in any of the eight patients.ConclusionsAlthough the radiographic signs of DEH are characteristic, (osteochondroma-like) parosteal osteosarcoma should be differentiated from DEH when there is a radiolucent separation line between the mass and host bone in the talus. Simple excision was effective in the management of DEH if the deformity was not complicated. Incompletely excised masses resolved and vanished with time.

Gastric cancer acrometastases to all digits of one hand following closed intramedullary nailing.

Metastatic malignant tumor of the hand is unusual and the most common site of the primary cancer is lung. Acrometastases to the phalanges of the hand usually involve a single bone, while those proximal to the phalanges often involve multiple bones. Metastasis to the hand from gastrointestinal cancer, particularly from gastric cancer, is extremely rare. To our knowledge, only five cases have been reported in the literature to date and there has been no reported case following closed intramedullary nailing for metastatic diaphyseal fracture of an ipsilateral long bone. We present a very unusual case of gastric cancer, which metastasized to all fingertips of the ipsilateral hand after closed interlocking intramedullary nailing of a pathologic fracture of the humerus.

Huge tophaceous pseudogout associated with tenosynovial chondromatosis arising from flexor digitorum tendon sheaths of the foot: a case report

Synovial chondromatosis (SC) is a benign proliferative process of synovial tissue creating multiple cartilaginous nodules in joints. It most commonly occurs in the large joints of the knee, hip, and shoulder, uncommonly in the small joints of the hand and foot, and only rarely in the tenosynovial membrane of tendon sheath, termed tenosynovial chondromatosis (TC). Unlike SC, TC predisposes to the foot or hand. The rarity and unfamiliarity of imagers with TC, as well as the variability of its histologic features often lead to an erroneous diagnosis of extraskeletal chondroma or even chondrosarcoma as in the present case. Calcium pyrophosphate dehydrate (CPPD) crystals are usually deposited in the articular cartilage or periarticular structures such as synovium and capsule, and rarely in other soft tissue structures including bursa, tendon, subcutaneous tissue, and dura mater. CPPD crystals may also be deposited in extraskeletal chondroma and SC. We present an exceptionally rare case of huge tophaceous pseudogout associated with TC that is considered to arise from the flexor digitorum longus tendon sheaths of the foot, initially mistaken for a chondrosarcoma.

Enchondroma Protuberans of the Hand

OBJECTIVE Enchondroma protuberans is a rare tumor that arises from an intramedullary enchondroma with an exophytic growth pattern. The purpose of this study was to describe imaging findings of this disease that were obtained using both radiography and MRI. CONCLUSION It is necessary to understand the characteristic imaging findings of enchondroma protuberans to avoid misdiagnosis. When radiography does not allow a clear diagnosis of enchondroma protuberans, MRI may be helpful for diagnosis.

Metastatic malignant tumour in the hand

Abstract Skeletal metastasis is a common event during the advanced stage of a malignant tumour, but metastasis to the hand is rare (about 0.1% incidence). We have seen seven cases of metastatic malignant tumour of the hand since 1983, and report them here.

Kimura’s disease involving a long bone

Kimura’s disease is a rare, benign lymphoproliferative disorder of unknown etiology. It occurs most often in Asian men, usually in the second or third decade of life. Most lesions occur in the head and neck followed by the axilla, groin, popliteal region, and arm. The lesions are commonly found in soft tissues. To the best of our knowledge, there has been only one case report of bone involvement in Kimura’s disease presented on plain radiography. We report a case of Kimura’s disease that involved the proximal meta-diaphysis of the humerus and adjacent soft tissue shown on radiography and MR imaging.

Desmoid tumor of bone with enchondromatous nodules, mistaken for chondrosarcoma

Abstract. Desmoid tumor of bone, also termed desmoplastic fibroma or aggressive fibromatosis, is a rare, locally aggressive fibroblastic tumor. We present a 16-year-old male with a huge desmoid tumor involving the iliac wing. It was associated with enchondromatous nodules mimicking malignancy. The tumor in this patient was mistaken for chondrosarcoma and hemipelvectomy was performed. To our knowledge, such a case has not previously been documented fully in the English literature. The radiographic and pathologic findings and a possible mechanism of enchondromatous nodule formation in fibrous bone tumors are discussed.

Infarct associated sarcoma: A possible pathogenesis based on histological observation of repair tissue origin in two cases

Although the absolute majority of bone sarcomas are primary in origin, transformed sarcomas occasionally arise from benign bone tumors or even nonneoplastic bone diseases [1,2]. Indeed, it has been proven that sarcomas develop from chronic infarct of the long bone, the incidence of which has been reported to be 1% of all bone sarcomas [3,4]. To date about 60 cases of infarct associated sarcomas (IAS) have been fi led in the world literature. The pathogenesis of IAS is not established although the reparative tissue adjacent to an infarct has been assumed as source of sarcomatous transformation [1,5 – 8]. To our knowledge no actual histological evidence to support the assumption has been published. Recently, we observed a defi nite transition zone to exist in the space between ancient infarct and transformed sarcoma in our two cases. The transition zone consisted of granulation tissues that included interlacing spindle cell fascicle, capillary proliferation with foamy macrophage and chronic infl ammatory cells and also cellular atypism of varying degrees. Furthermore, in the distal (sarcoma-side) transition zone atypical spindle cells were observed to imperceptibly merge into highgrade spindle cell sarcoma. We describe our histological observation of a transition zone between infarct and sarcoma, which might be an origin of sarcomatous transformation in bone infarct. A 58-year-old Korean male was referred to us because of severe, painful swelling of his left knee. Earlier, the pain was negligible lasting for four years but became aggravated during the recent six month period. He was bedridden due to intervening schizophrenic disorder and diabetes mellitus for years. No history of alcohol or steroid abuse, dysbaric working conditions, hemoglobinopathies, pancreatitis, Gaucher ’ s disease, or hereditary bone dysplasia was elicited. Pertinent laboratory data was within normal limits except mild anemia. Conventional radiography showed classic signs of multiple, ancient, bone infarcts involving both the right and left distal femora and proximal tibiae (Figure 1A). The infarct in the left proximal tibia was attended by bizarre expansive bone destruction with cortical rupture. Magnetic resonance (MR) imaging demonstrated bizarre signal intensity changes that matched well with radiographic fi ndings of infarcts and malignant transformation (Figure 1B). Scan microscopy showed a bone infarct (I) and sarcoma (OS) with a typical transitional zone (TZ) in-between (Figure 2A). Low-power microscopy revealed TZ to commence at the distal part of disintegrated infarct in where interlacing spindle cells were defi nitely bland on high power view (Figure 2B). The islands of infarct in the transformed part presented trabecular and marrow necrosis with irregular calcifi cations while the infarcts proper were completely free of malignant change. Medium-power view showed TZ to contain interlacing spindle-cell fascicles and capillary proliferation with foamy macrophage, chronic infl ammatory cells as well as atypical cells of varied populations. Atypical cells were sparse in number, if any, at the center of TZ (Figure 2C) and gradually increased in number and grade of cellular atypism as the sarcoma region was approached (Figure 2D). In the distal TZ atypical spindle cells imperceptibly Acta Oncologica, 2010; 49: 868–872

The impact of the International Atomic Energy Agency (IAEA) program on radiation and tissue banking in Korea

In 1971, first bone bank was established at the Department of Orthopaedic Surgery in Catholic University of Korea. The first clinical case was reported at the Journal of Korean Orthopaedic Association in 1973. Subsequently, more than 60 surgical bone banks were established in the university and teaching hospitals throughout country. In 1990, the Korea Biomaterial Research Institute (KBRI) organised the IAEA/RCA training course on tissue banking. In this course students from 17 countries participated. In 1994 the first collaboration for cadaver tissue recovery was performed. It is important to single out that the various religious groups in Korea have favourable attitudes towards tissue donation, which contributes to the success of the tissue banking programs in the country. The demands of allograft were getting increased in the Korean medical and dental society. Currently, 62 hospital based bone banks, 5 processing tissue banks, 1 regional tissue bank and more than 30 tissue distributors are working in Korea. Based on the U.S.A. usage of more than 1,000,000 grafts per year, 100,000–200,000 grafts will be needed in Korea. Those findings indicate a greatly increased need for training of tissue bank operators. The Korean society will need at least 20–30 tissue bank operators for training in every year. The National Training Centre (NTC) for tissue bank operators and medical personal using the IAEA Curriculum in the Korean languages was established in 2003. From 2004 to 2006, NTC have been trained 40 tissue bank operators. They have produced at least 10,000 tissues per year. These figures indicate a cost saving of US