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R A McLeod

Publications and source records attributed to R A McLeod.

At least 19 recordsLinked to original sources
PubMed2000

Clinicopathologic features and treatment of postirradiation sarcoma of bone and soft tissue.

BACKGROUND AND OBJECTIVES: An analysis of the clinicopathologic features and treatment of patients with postirradiation sarcoma of bone and soft tissue was performed to guide modern evaluation and management. METHODS: A retrospective analysis of 135 sarcomas in 130 patients was performed. RESULTS: The mean age of the 130 patients was 48 years, and there was a female predominance because of irradiation for carcinomas of the breast and uterus. Indication for irradiation was a soft tissue lesion (such as lymphoma or breast cancer) in 58.5% of patients and a bone lesion (such as giant cell tumor or fibrous dysplasia) in 41.5%. The latent period (interval between irradiation and discovery of the sarcoma) ranged from 4-55 years (mean, 17 years). Of the lesions, 74% were stage IIB (high-grade extra-compartmental) and 24% were stage III (metastases). Ninety-four patients received their treatment at our institution. Of the 61 patients with resectable disease, 49 had amputations and 12 had limb salvage procedures. The 5-year cumulative survival rate was 68.2% for patients with peripheral (extremities, including proximal femur and hip) resectable lesions and 27.3% for patients with central (pelvis, head/neck, and ribs) resectable lesions. The local recurrence rate correlated with the surgical margin achieved: intralesional, 73%, marginal, 64%, and wide, 23%. CONCLUSIONS: The prognosis for patients with peripheral resectable postirradiation sarcomas is good if a wide surgical margin can be achieved. This group of patients should be treated aggressively because they have a new cancer.

Adolescent↗
PubMed1998

Primary chondrosarcoma of long bones and limb girdles.

BACKGROUND: Chondrosarcomas are common solid malignant tumors of bone, second in incidence only to osteosarcomas. The biologic evolution of chondrosarcomas is slow, requiring long follow-up intervals for meaningful survival analysis. METHODS: This study describes the clinicopathologic profiles of 344 patients, 194 male and 150 female (M:F, 1.3:1.0), with primary chondrosarcoma of long bones and limb girdles seen at 1 institution over a period of 80 years. RESULTS: The average age at presentation was 46 years (range, 5-82 years). The pelvis was the most common location (1.7% of all patients). Local pain was the most frequently reported initial symptom (81.4%). Survival analysis was limited to 233 patients whose primary treatment was given at the Mayo Clinic. All 233 patients had potential follow-up of at least 5 years. The overall 5-year survival rate was 77% (the expected rate was 96%). Local recurrence developed in 19.7% of patients and metastatic lesions in 13.7%. The recurrence rate was higher for tumors of the shoulder and pelvis than for tumors of long bones. Radiographically, chondrosarcomas had a characteristic appearance, including a combination of bone expansion and cortical thickening. Entering the tumor at surgery increased the risk of local recurrence. Histologic tumor grade was an important predictor of local recurrence and metastasis. CONCLUSIONS: With adequate initial surgical intervention, chondrosarcoma is primarily a local disease with a low metastatic rate.

Adolescent↗
PubMed1997

Screen-film versus computed radiography imaging of the hand: a direct comparison.

OBJECTIVE: Computed radiography of the musculoskeletal system has the potential to become a powerful tool in the practice of diagnostic radiology. It addresses many of the geographic and film-distribution concerns facing diagnostic imaging. We undertook this study to compare and document the quality of computed radiographs and conventional screen-film images before widespread implementation. MATERIALS AND METHODS: We evaluated clinical images using direct comparison. Bilateral hand images from 50 patients were scored independently by six musculoskeletal radiologists. In each case one hand was imaged with a conventional screen-film technique and the other with computed radiography. Images were masked to eliminate as much bias as possible. The numeric scores assigned to the images by the observers were analyzed using Student's t test. RESULTS: Computed radiographs were judged with statistical significance to be better than conventional screen-film images in all features judged by the observers, including bone cortex, bone trabeculae, corticomedullary junction, distal phalangeal tuft, soft tissues, fat planes, bone-soft-tissue interface, and overall contrast and density. CONCLUSION: The statistically significant determination that the image quality of computed radiographs is at least as good as screen-film images allows confident use of computed radiography and enables radiologists to take advantage of its many other practical capabilities related to image distribution, storage, cost, and geographic coverage without sacrificing image quality.

Adult↗
PubMed1996

Epithelioid hemangioendothelioma of bone.

Epithelioid hemangioendothelioma of bone is a rare tumor of vascular origin. A series of 40 cases from the Mayo Clinic files was studied to define the pathologic features of this disease and to evaluate any histologic or clinical factor influencing outcome. More than 50% of the tumors were multicentric, with a predilection for bones of a particular anatomical area. In this series, patients with multifocal tumors did not have a better prognosis than those with unicentric disease. We could not predict the outcome of cases on the basis of the histologic features. Visceral involvement was the most important criterion in predicting prognosis. Resection is still the primary treatment for these tumors. Radiotherapy may be useful for surgically inaccessible tumors. Too few patients have received adjuvant chemotherapy to evaluate its usefulness in this setting.

Adolescent↗
PubMed1996

Low grade central osteogenic sarcoma. A long-term followup of 20 patients.

Osteogenic sarcoma is a heterogeneous family of tumors that has a variable biologic behavior. Low grade central osteogenic sarcoma is an uncommon form that is characterized by a long premorbid history and is compatible with prolonged survival after treatment. Twenty cases of low grade central osteosarcoma with long-term followup (16 [2.5-48] years) were studied retrospectively. The age distribution was broad (range, 15-83 years). All tumors arose in the lower limb. The primary symptom was pain; mean duration was 44 months (range, 1-180 months). A diagnosis of low grade central osteosarcoma was made primarily for 11 patients. For 9 others, fibrous dysplasia (3), nonossifying fibroma (2), fibroma (1), chondromyxoid fibroma (1), chondrosarcoma (1), and simple bone cyst (1) were diagnosed initially. Intralesional surgery was associated with recurrence in every case. Radical margins were not associated with local recurrence. Four recurrences were higher grade and 1 was dedifferentiated. Three of 4 patients with metastases died of their disease. Five- and 10-year survival was 90% and 85%, respectively. Histology and radiology are complementary for confirming the diagnosis. Low grade central osteosarcoma seems to be controllable by surgery alone if at least wide margins are used.

Adolescent↗
PubMed1996

Elastofibroma dorsi: radiologic findings in 12 patients.

OBJECTIVE: We report radiologic findings in 12 patients with elastofibroma dorsi to heighten radiologist awareness of the imaging characteristics of these benign, often asymptomatic lesions. Because these lesions can usually be diagnosed on the basis of their imaging characteristics, increased awareness of these characteristics will decrease misdiagnosis of these lesions as malignancies and avoid unnecessary biopsies and surgeries. MATERIALS AND METHODS: We retrospectively reviewed the radiology and pathology of nine patients with surgically excised elastofibromas and the radiology of three patients with radiologically diagnosed elastofibromas. RESULTS: Twenty-one elastofibromas were imaged in 12 patients. Female-to-male ratio was 5:1; mean age was 65 years old. Of the nine patients in whom both sides of the chest wall were imaged, all (100%) had bilateral elastofibromas. Nineteen elastofibromas (90%) had the typical CT and MR appearances described in the literature: a poorly circumscribed, heterogeneous soft-tissue mass, with tissue of attenuation or signal intensity similar to that of skeletal muscle interlaced with strands of fat. One elastofibroma imaged twice over a 4-year period showed interval growth. All elastofibromas were sub- or infrascapular or in both locations. Of the 21 elastofibromas imaged, only four were perceived by the initial interpreting radiologist, and of these, only one was correctly diagnosed. CONCLUSION: Our study shows that many radiologists may not be aware of the diagnosis of elastofibroma, as few of the cases in our series were perceived or correctly diagnosed by the interpreting radiologist. Our cases show many of the classic findings of elastofibromas described in the literature. In addition, our series shows that elastofibromas are commonly bilateral, a feature that has not been strongly emphasized in the literature but one that is helpful in making the radiologic diagnosis. The finding of a similar contralateral lesion, when present, virtually eliminates malignancy from the differential diagnosis and further supports the presumptive diagnosis of elastofibromas. Increased awareness of the characteristic appearance and location of these benign, often asymptomatic lesions will increase radiologic diagnosis, decrease the need for biopsy, and decrease surgical removal of elastofibromas as presumed malignancies.

Aged↗
PubMed1996

Osteoblastoma.

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Adolescent↗
PubMed1995

The importance of bone biopsy in managing renal osteodystrophy.

A case is presented in which bone biopsy results helped to resolve not only difficult issues in the clinical management of the patient's renal osteodystrophy but also disruptive psychosocial problems surrounding her clinical course. The outcome was a satisfactory resolution based on rational medical treatment and directed supportive care. The presentation highlights important principles in the procurement, processing, and interpretation of the bone biopsy, while also addressing the importance of accurate diagnosis in facilitating the overall long-term management by the entire renal team.

Aged↗
PubMed1995

Ewing's sarcoma.

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Antineoplastic Agents↗
PubMed1994

Osteoblastoma: clinicopathologic study of 306 cases.

The clinical, radiologic, and pathologic features of 306 osteoblastomas were analyzed. Seventy-five were Mayo Clinic cases and 231 were from consultation files. Males outnumbered females two to one. The age range was 6 months to 75 years (mean age, 20.4 years). The vertebral column including the sacrum was the most frequent site (32%). Pain was the usual complaint and neurologic findings were associated with vertebral tumors. Although most tumors were well circumscribed, cortical expansion and destruction were common radiographic findings (39%), and 12% had features suggestive of malignancy. Large, epithelioid osteoblasts were seen in 24% and were the predominant cellular element in 10%. A distinctive epithelioid multifocal pattern was recognized. Recurrence rates were 16% (Mayo Clinic cases) and 21% (consultation cases). Tumors involving the central neuraxis were associated with greater morbidity and mortality. Aggressive behavior is within the biologic spectrum of osteoblastomas, and histopathology alone does not appear to be a reliable predictor of aggressiveness. The most important differential diagnosis is osteosarcoma.

Adolescent↗
PubMed1993

Chondroblastoma.

Chondroblastoma of the bone is a benign tumor that has well-characterized radiographic and histologic features. It tends to affect the epiphyseal ends of long bones in men during the second and third decades of life. The tumor is located more frequently at other sites in older patients. The treatment of choice is complete curettage with bone grafting, which in our series provided local control in 82% of patients at 2 years' follow-up. Recurrent tumors usually can be treated in the same manner.

Adolescent↗
PubMed1993

Osteofibrous dysplasia: clinicopathologic study of 80 cases.

A thorough review of the clinical, radiologic, and histologic features of 80 cases of long bone osteofibrous dysplasia is presented. Of the six cases of osteofibrous dysplasia immunostained with a cytokeratin antibody, two were cytokeratin positive; however, the five cases of fibrous dysplasia that were stained were all negative. Follow-up (mean, 5.4 years; range, 1 month to 31 years) data were available for 41 cases (51%). From the consultation series nine of the 18 patients studied had recurrences, regardless of the different treatment regimens. The average recurrence interval in these patients was 2.7 years. Two patients had incomplete excision and six had biopsy only. All eight of these patients had residual tumors. Among the 16 Mayo Clinic patients, one had recurrence 5 years after the initial treatment. In two cases, 7-year-old and 6-year-old boys, histologic maturation to fibrous dysplasia was observed 4 and 10 years later, respectively. Adamantinoma has not developed in any of the 41 cases of osteofibrous dysplasia for which we have follow-up information. It seems clear that osteofibrous dysplasia does not progress to adamantinoma. Our study suggests that osteofibrous dysplasia is probably a variant of fibrous dysplasia, as demonstrated by the maturation of two lesions of osteofibrous dysplasia to fibrous dysplasia. Surgical treatment may be appropriate in cases with an extensive lesion, pseudoarthrosis, and accentuated tibial bowing. The overall prognosis is good, even with recurrence.

Adolescent↗
PubMed1993

Giant-cell tumours of the spine.

Between 1955 and 1989 we treated 24 patients (17 women and seven men) with giant-cell tumours of the spine at the Mayo Clinic. Their mean age was 30 years and the mean follow-up time was 12.4 years. Pain was the presenting symptom in all and half had a neurological deficit. The cervical, thoracic, and lumbar spines were equally involved. The tumours recurred in five of the 14 patients treated by one-stage surgery and in five of the ten treated by two-stage surgery. Seven patients received adjuvant radiotherapy, one for the primary lesion and six for recurrent lesions. Surgical management was by curettage or en bloc excision depending on the location and the extent of the tumour. Because of the risk of sarcomatous transformation, radiation therapy should be reserved for patients with incomplete excision or for those with local recurrence.

Adolescent↗
PubMed1993

Treatment of giant-cell tumor of the pelvis.

Nineteen patients who had a giant-cell tumor of the pelvis were managed from 1944 through 1989. Thirteen of the patients were in the third or fourth decade of life. The ileum was involved in thirteen patients; the pubis, in two; the ischium, in three; and the pubis and ischium, in one. Five patients who had an initial Stage-II (active) lesion were managed with curettage; in one of the five, a local recurrence developed at twelve months, and the other four had no evidence of disease from nine to forty-six years after the curettage. Eight patients who had a Stage-III (aggressive) lesion were managed with resection of most of the lesion followed by curettage of any remaining positive margins; four of the eight also received adjuvant irradiation. None of the eight had a local recurrence; six had no evidence of disease from eight to twenty-seven years after the operation, one died because of a metastatic post-radiation sarcoma thirteen years after the operation, and one was asymptomatic but had pulmonary metastases three years after the operation. Four patients who had a Stage-III recurrent local tumor when they were first seen were managed with hemipelvectomy, wide resection, resection and curettage, and curettage and arthroplasty (one procedure each). Three had no evidence of disease seven to twenty years after the operation and one had died because of a post-radiation metastatic osteosarcoma eight years after the operation. Two patients who had Stage-III disease were managed with external beam radiation alone. One had no evidence of disease twenty-six years later. The other had a recurrence one year later, which was treated with additional irradiation; a second recurrence was treated with curettage and bone-grafting. Twenty-eight years after the initial radiation treatment, this patient had no evidence of disease. External beam irradiation was used for a total of eight patients; a post-radiation sarcoma developed in two.

Adolescent↗