S. M. Kumta

Classifying the location of osteosarcoma with reference to the epiphyseal plate helps determine the optimal skeletal resection in limb salvage procedures

Abstract Between 1989 and 1996, 21 skeletally immature patients were treated for osteosarcoma of the extremity. Their average age was 12.6 years (range 9–16 years). We classified the location and extent of the lesion in bone on magnetic resonance imaging (MRI) with reference to the growth plate and joint margin into five subtypes. This classification served as a guide for the level of resection and the type of reconstruction required for a limb salvage procedure. All patients received neoadjuvant chemotherapy using a modified T10 protocol before the definitive operation. These patients were followed up for periods ranging from 11–86 months, with a mean of 35.5 months. Patients were assessed for (1) local tumour recurrence, (2) metastatic disease, (3) allograft complications and (4) extremity function and joint stability. Excellent function was retained in 2, good in 13 and fair function in 6 patients. The MRI classification proved useful for the resection and provides an insight into the possible functional outcomes.

Monostotic fibrous dysplasia of the spine: report of a case involving the lumbar transverse process and review of the literature.

Abstract Monostotic fibrous dysplasia of the spine is rare. We report its clinical, radiologic and histologic features affecting a 47-year-old housewife. She presented with low-back pain of 1-year’s duration, and radiographs showed a diffuse expansile lesion in the left transverse process of the fourth lumbar vertebra. The lesion was excised and histologically confirmed to be fibrous dysplasia. The patient remained well 8 years after operation. Including the present case, a total of 22 cases of monostotic fibrous dysplasia of the spine were found in the literature. Combining these reported cases, we found that the condition affects either sex with equal frequency and presents at any age, the mean being 32 years. There is no predilection for any part of the spinal column, though sacral or coccygeal involvement is distinctly rare. It most commonly involves the body and adjacent pedicle, although no part of the vertebra is spared. It is worth noting that a propensity for progressive enlargement, even to the extent of causing graft destruction, exists if the lesion is left untreated or incompletely treated. Complete removal of all involved bone, together with stabilization, should therefore be the treatment of choice for this condition.

Extra-articular pigmented villonodular synovitis of the temporomandibular joint

Pigmented villonodular synovitis, a benign but locally destructive fibrohistiocytic proliferative lesion involving tendon sheaths, bursae and diarthrodial joints, is distinctly rare in the temporomandibular joint. We report one such case occurring in a 42-year-old housewife who presented with a progressively enlarging right zygomatic mass for six months. On exploration, an orange-brown firm mass, 5 x 3 x 2 cm, was seen adherent to the lateral aspect of the capsule of the right temporomandibular joint, and eroding into the inferior aspect of the right temporal bone and part of the mandibular condyle. The mass was completely excised. Pathological examination showed features typical of those of pigmented villonodular synovitis and the lesion was entirely extra-articular in location. The patient remained well with no evidence of local recurrence two years after operation. Review of the literature and careful analysis of the clinicopathological features showed that the vast majority of the reported cases of pigmented villonodular synovitis of the temporomandibular joint belonged to the extra-articular variant, which is associated with a more aggressive local infiltrative behaviour and higher rate of local recurrence than the localized type. The recommended treatment for this condition is therefore wide local excision, aiming to remove the lesion as completely as possible without producing severe disability for the patient.

Revascularisation of bone allografts following vascular bundle implantation : an experimental study in rats

Revascularisation and cellular repopulation of fresh and cryopreserved allografts was observed following implantation of a vascular bundle in an experimental study in rats. Fresh and cryopreserved rat allografts were harvested from Lewis rats and implanted into Spraque-Dawley rats. The femoral vascular bundle was implanted into 2-cm segments of allograft placed in the medial aspect of the thigh of the recipient rats. Non-vascularised controls were used for comparison. Histological studies indicated the revascularisation pattern. Cryopreserved allografts with vascular bundle implantation showed early neovascularisation from the endosteal surface, 20% of the necrotic lacunae was repopulated with living cells at the end of 24 weeks. Fresh allografts with vascular implantation were rejected by the host immune mechanisms and showed early breakdown and fragmentation. Cellular repopulation was not observed in the non-vascularized allografts. Secondary vascularization following a vascular bundle implantation may enhance the biological properties of an allograft and therefore has significant potential clinical applications.

Vascularised bone grafting for fibrous dysplasia of the upper limb

We describe our experience with vascularised bone grafting for the treatment of fibrous dysplasia of the upper limb in eight patients, five men and three women, aged between 17 and 36 years. The site was in the humerus in six and the radius in two. Persistent pain, progression of the lesion and pathological fracture with delayed union were the indications for surgical intervention. We used a vascularised fibular graft after curettage of the lesion. Function and radiological progress were serially monitored. Early radiological union of the graft occurred at periods ranging from 8 to 14 weeks. The mean period for reconstitution of the diameter of the bone was 14 months (12 to 18) predominantly through inductive formation of bone around the vascularised graft, which was a prominent feature in all patients. There were no recurrences and none of the grafts sustained a fracture or failed to unite. After operation function was excellent in three patients and good in five. Vascularised bone grafts provide a safe and reliable means of ensuring good continuity of bone with little risk of recurrence and failure.

Chondromyxoid fibroma‐like osteosarcoma: a distinct variant of low‐grade osteosarcoma

Chondromyxoid fibroma‐like osteosarcoma is a recently described, extremely rare subtype of low‐grade osteosarcoma. Two such cases were encountered among 102 cases of osteosarcoma seen in the Prince of Wales Hospital, Hong Kong, between 1984 and 1994. The first patient, a 39‐year‐old woman, presented with a mass in her right maxilla which was resected and mistaken as a myxoma. The tumour recurred locally four years later and she now has extensive local recurrent disease six years after initial presentation and is amenable to support treatment only. The second patient, a 28‐year‐old man, had a pelvic tumour which recurred in the form of a polypoid left atrial tumour and pulmonary nodules six years after operation. The left atrial tumour recurred one year after operation, and led to sudden death of the patient seven years after initial presentation. Radiologically, the tumours in both cases appeared as expansile osteolytic lesions with erosion of adjacent bone and infiltration into soft tissue. Histologically, they consisted of lobules of spindle, stellate or polygonal tumour cells showing mitotic activity and with moderate nuclear pleomorphism and hyperchromatism, set in a highly myxoid stroma superficially mimicking chondromyxoid fibroma. The histological hallmark was the direct production of osteoid by tumour cells. Chondromyxoid fibroma‐like osteosarcoma merits recognition as a distinct variant of low‐grade osteosarcoma for which early appropriate surgery is indicated.

Primary juxtacortical chondrosarcoma dedifferentiating after 20 years

Abstract We present the clinical, radiographic and pathological features of a juxtacortical chondrosarcoma which underwent dedifferentiation to an osteosarcoma in a 47-year-old woman. The tumour, abutting the femoral diaphysis, had initially presented 20 years earlier. Local excision was performed at presentation and again 10 years later, but the tumour recurred on each occasion. Serial radiographs showed cortical saucerisation evolving to cortical buttressing and mounding. After 20 years a dramatic radiographic change heralded tumour dedifferentiation.

Angiomatoid malignant fibrous histiocytoma : Report of an unusual case with highly aggressive clinical course

The authors report a case of angiomatoid malignant fibrous histiocytoma (AMFH), affecting a 9-year-old girl, with a highly aggressive clinical course. The tumor, noticed by the patient as a painless nodule in the dorsum of her left foot for 12 months, recurred 8 months after initial excision, and despite wide local reexcision, metastasized 4 months later to the liver and lung, where it grew at an alarming rate, to the extent of occupying the entire left hemithorax in a period of 10 weeks and killed the patient 14 months after initial excision. Review of the literature showed that the culminated rates of recurrence, metastasis, and mortality for AMFH were 23.2%, 8.7%, and 4.3%, respectively, indicating that it is definitely a malignant neoplasm with a potentially fatal outcome.

Primary osteochondrorhabdomyosarcoma (malignant mesenchymoma) of the fibula: a rare tumour in an unusual site -- case report and review of the literature.

Malignant mesenchymoma, defined by Stout as sarcomas comprising two or more unrelated differentiated tissue elements other than a fibrosarcoma component, is rare. We report a case of primary malignant mesenchymoma of the proximal fibula in a 10‐year‐old female student who presented with pain and swelling of the right knee for 2 months. Initial biopsy showed features of rhabdomyosarcoma only, but the resected specimen revealed additional osteosarcomatous and chondrosarcomatous elements. The patient remained well more than 5 years after initial presentation. Including our present patient, 16 cases of primary malignant mesenchymoma of bone are found in the English literature, affecting mainly adolescents and young adults, with a slight male predominance and predilection for the metaphysis of long bones, especially around the knee. More than 60% of the patients develop metastasis, almost invariably to the lung, but occasionally to the brain. About 60% of the patients, all with metastasis, died mostly within one year of diagnosis. The clinical features of primary malignant mesenchymoma of bone thus resemble those of conventional osteosarcoma. Moreover, our case illustrates that, with combination chemotherapy targeted for individual elements, the prognosis of this rare tumour might be much improved, as in osteosarcoma.

Massive intestinal hemorrhage resulting from a polypoid tumor in the sigmoid colon: an unusual complication of a giant cell tumor of the fifth lumbar vertebra.

Study Design. Clinicopathologic study of a case of giant cell tumor of the spine. Summary of Background Data. Giant cell tumors of the spine are uncommon, accounting for 1.3–6.5% of all cases in various series. Because of their location, they may cause neurologic deficits. The treatment consists of en bloc excision or curettage and has been claimed to give good results. Methods. A 33-year-old woman presented with low back pain in 1995; radiologic investigation and biopsy showed features of giant cell tumor involving the fifth lumbar and first sacral vertebrae. Wide excision was performed, but the tumor recurred in 1996 and was curetted. She developed massive intestinal bleeding in 1997 resulting from infiltration of the sigmoid colon by giant cell tumor in the form of a polypoid intraluminal mass. The involved segment of colon was resected, and the patient remained alive, although debilitated, 7 years after initial presentation. Results. Examination of the tumor in the spine and the colon showed typical histology of giant cell tumor with no evidence of malignant transformation. The involved colon was freely mobile and away from the tumor of the spine. Conclusion. Giant cell tumor of the spine can result in unusual complication, massive intestinal hemorrhage in our case, which causes considerable morbidity.