Krishnan K. Unni

MESENCHYMAL CHONDROSARCOMA OF BONE AND SOFT TISSUE. A REVIEW OF 111 CASES

A series of 111 mesenchymal chondrosarcomas was reviewed. The ages of the patients ranged from 5 to 74 years, and approximately 60% of them were in the second and third decades of life. There was no significant sex predilection. Seventy‐two tumors, including 5 that involved multiple skeletal sites, arose in bone. Thirty‐eight tumors were found in extraskeletal sites. At initial diagnosis, multifocal involvement, both in bone and in soft tissue, was observed in one case. Roentgenographically, the lesions in bone frequently resembled ordinary chondrosarcomas, showing osteolytic and destructive appearances with stippled calcification. Tumors in extraskeletal sites were almost always identified as calcified masses. Histologically, a combination of cellular zones composed of undifferentiated small cells and chondroid zones typically presented a bimorphic appearance that was virtually pathognomonic in most cases. Ablative surgical treatment seemed to be the procedure of choice. The value of irradiation or chemotherapy (or both) was difficult to assess in the current study. Prognosis for patients with mesenchymal chondrosarcoma is usually poor, and long‐term follow‐up is necessary. In a group of 23 patients from the Mayo Clinic, the 5‐year survival rate was 54.6% and the 10‐year survival rate was 27.3%. Cancer 57:2444–2453, 1986.

Malignant lymphoma of bone

A total of 422 patients with malignant lymphoma of bone who were seen at the Mayo Clinic from 1907 through 1982 were placed into four major groups based on stage of disease. There was one group with primary lymphoma of bone, one group with multifocal osseous lymphoma, and two groups with lymphoma of bone and nodal or soft tissue (or both) disease. The last‐mentioned two groups were separated on the basis of time of onset of osseous lymphoma in relation to the nonosseous disease. The stage of disease was the single most important prognostic indicator of overall survival in malignant lymphoma of bone. The 5‐and 10‐year survival rates were, respectively, 58% and 53% for patients with primary bone lymphoma, 22% and 12.5% for patients with bone and nodal or soft tissue (or both) disease, and 42% and 35% for patients with multifocal osseous disease. Features having no significant prognostic value were sex of the patient, histologic grade of the lymphoma (according to the Working Formulation and the Kiel system), and presence of T‐cell features or cleaved cells (or both). This study is not able to adequately address efficacy of treatment. In fact, treatment may be very important in outcome.

Osteosarcoma of the jaw

The records of 66 patients with osteosarcoma of the jaw were reviewed. The ages of the 42 males and 24 females ranged from 12 to 79 years (mean, 34.2 years). Swelling and pain, the most frequent presenting complaints, were noted an average of three months before the patient was seen by a physician. Fifty‐one percent of the lesions involved the maxilla and 49% involved the mandible. The most common sites of involvement were the body of the mandible and the alveolar ridge of the maxilla. Radiologically, most of the lesions in the maxilla were osteoblastic (50%), whereas most of those in the mandible were osteolytic (43%). Chondroblastic osteosarcoma was the most frequent histologic type (48%) and was associated with the best survival rate (47%). Treatment included radical and local surgery with radiotherapy, chemotherapy, or various combinations. The recurrence rate for all treatment modalities was 70%. Patients treated by initial radical surgery had the best survival (80%). Survival decreased to 27% with local surgery. Of the 43 (65%) patients who died, most died with uncontrolled local disease; only four patients had documented distant metastasis, which involved lung, cervical lymph nodes, spinal column, and brain.

Chondrosarcoma arising in osteochondroma

Secondary chondrosarcomas are rare. An analysis of 75 cases of chondrosarcomas secondary to osteochondroma (42 lesions were from the Mayo Clinic files and 33 were from consultation files) revealed that 40 of the patients had single exostosis and 35 had multiple lesions. More males than females were affected, and most of the patients were age 20 to 40 years. The tumors involved various bones. Malignant change was manifested radiologically by fuzzy margins of the cartilage cap and by the presence of lucent zones within the lesion. Grossly, the surface of the thickened cartilage cap was irregular. Microscopically, most of the tumors were well‐differentiated (Grade 1). Treatment was surgical. Simple excision of the tumor resulted in a large recurrence rate. Resection and amputation were generally curative. Only 12 of the patients have died of their tumor. Most patients died of local recurrence. Only two of the 75 patients had definite evidence of metastatic disease.

Metastases from histologically benign giant-cell tumor of bone.

Metastasis from a giant-cell tumor of bone that is histologically benign has become a recognized entity. To date, thirty-one pathologically proved cases have been reported in the world literature. To this, we add eight cases from our experience of more than 400 cases of histologically benign giant-cell tumor of bone. The lungs are the principal site of metastasis, the lesions being pathologically indistinguishable from the primary tumor. The metastatic process is unpredictable as to clinical aggressiveness, and the mortality rate is approximately 25 per cent. We advise aggressive attempts at complete extirpation of metastases.

Ewing's sarcoma of bone. Experience with 140 patients

The records of 140 patients with histologically verified Ewings sarcoma of bone treated between 1969 and 1982 were studied retrospectively. Various factors thought to be relevant to prognosis were analyzed. Three statistically significant factors were found: presence of metastatic disease, elevation of the sedimentation rate, and location of the tumor in the pelvis. In addition, patients who underwent complete surgical excision of the primary lesion had a better survival rate (74% at 5 years) than those who did not (34% at 5 years). It is concluded that patients with surgically accessible lesions should undergo treatment consisting of surgery, chemotherapy, and, in selected cases, radiation.

Osteosarcoma of bone and its important recognizable varieties.

Osteosarcoma of bone is a recognizable entity if the histopathologist designates tumors as such when their malignant cells produce osteoid substance even if only in small foci. Such definition distinguishes this lesion from other sarcomas that arise in bone, especially chondrosarcoma and fibrosarcoma. There is a general tendency to consider that osteosarcomas represent a stereotyped form of disease for which new modalities of treatment can be applied and assessed. The question of whether a given osseous lesion is actually malignant and not a benign neoplasm or even a reactive non-neoplastic condition simulating a malignant tumor may be difficult for the histopathologist. Pathologists without considerable experience in the diagnosis of bone tumors find this question especially vexing. The establishment of a valid diagnosis of osteosarcoma introduces the additional problem that the 11 varieties considered in this paper may pose significant recognizable variations in the clinical capability of the disease. It is apparent that the physician must recognize the known clinicopathologic and prognostic factors of these subtypes in his assessment of the overall problem.

Malignant (fibrous) histiocytoma of bone-fact or fancy?

Malignant (fibrous) histiocytoma is currently defined as a malignant primary bone tumor that contains a mixture of fibrogenic cells and cells that are histologically similar but which appear to be histiocytic. In this type of histiocytoma the nuclei are often indented; cytoplasm is usually abundant and may be slightly foamy; nucleoli are often large; and multinucleated malignant cells are usually a prominent feature. Many dedifferentiated chondrosarcomas, osteosarcomas, and fibrosarcomas of bone contain areas that resemble what we regard as malignant (fibrous) histiocytoma. When the entirety of a malignant tumor of bone fits the outlined histologic pattern, the designation of malignant (fibrous) histiocytoma seems appropriate. From 158 fibrosarcomas of bone and 962 osteosarcomas of bone in our files, 35 tumors were segregated because they appeared to be properly designated as malignant (fibrous) histiocytoma. A wide age range was represented by affected patients, and a large variety of bones harbored these tumors. Approximately one‐third of patients eligible for 5‐year follow‐up were long‐term, symptom‐free survivors. Four deaths occurred from the tumor after more than 5 years, and one patient had radiographic evidence of pulmonary metastasis 7 years after amputation. Radiation therapy has been curative in at least two cases. The correct designation for these tumors in the light of current knowledge is malignant tumor, consistent with malignant (fibrous) histiocytoma.

Clinicopathologic study of sacrococcygeal chordoma

Chordoma involving the sacrum is a rare neoplasm. Between 1952 and 1979, 63 patients underwent surgical treatment at the Mayo Clinic. Most of the patients were treated by en bloc excision by a posterior approach. For the 25 patients who had complete excision of the tumor without contamination of the surgical wound, the recurrence rate was 28%. For the 25 patients whose tumor was entered at surgery, the recurrence rate was 64%. in addition to recurring locally, this tumor may metastasize to distant sites. More aggressive surgery seems indicated.

Parosteal osteogenic sarcoma.

A clinicopathologic study of 79 patients with parosteal osteogenic sarcoma revealed that more females than males were affected and that most of the patients were in the second to the fourth decades of life. Sixty‐eight percent of the patients had involvement of the posterior aspect of the lower femoral shaft. The roentgenogram characteristically showed a large, dense lobulated mass attached by a broad base to the underlying bone but with no involvement of bone itself. Microscopically, the tumor presented as well‐formed bands of osteoid within a hypocellular spindle cell stroma. Seven of the lesions had foci of high‐grade osteogenic sarcoma within an otherwise typical parosteal osteogenic sarcoma. Six of the 79 lesions showed involvement of the medullary cavity at surgery. Thirty‐one patients had excision as their initial treatment; four of the 31 required no further therapy. Ten patients had resection initially; three of the ten had recurrence. Only four of 27 patients who underwent amputation initially developed pulmonary metastasis. The presence of histologically “active” tumor and medullary involvement seemed to affect the prognosis adversely. Our data indicate that complete radical removal of the the tumor is the treatment of choice, with resection when feasible and amputation when necessary.