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This article reviews the pathologic features and the behavior of 39 small, round, or oval cell sarcomas occurring in the soft tissues and considered histologically indistinguishable from Ewing's sarcoma of bone. The tumors affected chiefly young adults (median age 20 years) and most commonly involved the soft tissues of the lower extremity and the paravertebral region. Microscopically, they consisted of solidly packed small, round, or ovoid cells of great uniformity, arranged in sheets or lobules separated by strands of fibrous connective tissue. The nucleus of the tumor cells contained finely divided chromatin, a distinct nuclear membrane, and frequently a minute nucleolus. The scanty ill-defined cytoplasm contained varying amounts of glycogen. Sometimes the histologic picture was dominated by a "peritheliomatous" pattern, or by large areas of necrosis or hemorrhage. Followup data ranging from 1 month to 14 years were available in 35 of the 39 cases (93%). Of these, 13 were alive and 22 had died. In the majority of the fatal cases, the clinical course was rapid; metastatic lesions developed within a few months after the primary tumor was excised. The lungs and the skeleton were the two most common sites of metastasis. Cure may be achieved by wide local excision of the tumor at an early stage of the disease, combined with radiation therapy and chemotherapy.

The clinical courses of 60 patients with hemangiopericytoma of the somatic soft tissues are summarized in this retrospective study. The tumors were subjected to a comparative histologic review and classified as benign (12 lesions), borderline malignant (16 lesions), and malignant (32 lesions). Tumors with 1 mitotic figure per 10 high-power field and moderate cellular anaplasia or 1 mitotic figure per 20 high-power fields and moderate cellular anaplasia may be expected to follow a malignant clinical course. Six of the 16 tumors with these microscopic features (borederline lesions) metastasized (37.5%), and 6 exhibited local recurrences after excision. Of the 32 malignant tumors, 25 (78%) metastasized. Twenty-three patients with malignant tumors were followed for more than 5 years or until death from tumor, and only one patient was alive and free of disease. Fifteen of the 23 patients experienced one of more local recurrences. None of the benign tumors metastasized. Surgical ablation of hemangiopericytioma is, in our experience, the only satisfactory method of treatment. Amputation of an extremity need be done only when the location of the lesion precludes a wide local excision. Local recurrent tumor was experienced by 22 patients after an inadequate local excision. Long-term follow-up is recommended because metastasis became apparent in 11% of patients with malignant tumors and 7% with borderline tumors after 5 "disease-free" years.

This is the seventh reported case of soft tissue sarcoma attributed to thorotrast extravasated during the course of an injection for arteriography. An extraskeletal osteosarcoma occurring the cervical region of a 51-year-old man 30 years after a cerebral arteriogram is presented. The other reported cases include a fibrosarcoma, two neurofibrosarcomas, two spindle cell sarcomas, and an extraskeletal chondrosarcoma. The latency period has varied from 5 to 30 years. The thorotrast granules are readily identified in macrophages near or adjacent to the tumor, and the demonstration of alpha tracks on autoradiographs is diagnostic.

Spindle cell lipoma is a specific type of lipoma that is easily mistaken for a liposarcoma. An analysis of 114 cases of this tumor from the files of the Armed Forces Institute of Pathology reveals that is occurs chiefly in male patients between 45 and 70 years of age and affects the regions of the shoulder and posterior neck almost exclusively. Microscopically, it consists of an intricate mixture of lipocytes and uniform spindle cells within a matrix of mucinous material traversed by a varying number of birefringent collagen fibers. Ultrastructural studies in one case support the fibroblastic nature of the spindle cells. Followup information obtained in 63 patients with this lesion revealed a uniformly favorable clinical course, indicating that local excision is the treatment of choice, and that there is no need or reason for radical surgical procedures.

A patient with a clear cell sarcoma of tendons and aponeuroses arising in the left sacral area is reported. The tumor grossly contained two black foci that had pigment with the staining characteristics of melanin on light microscopy. Electron microscopy of these areas showed the pigment to be within melanosomes. This is the second report of a neoplasm diagnosed as clear cell sarcoma in which melanin was demonstrated; the possibility that the tumor represents a soft tissue variant of malignant melanoma is discussed. It is suggested that clear cell sarcoma is a heterogeneous entity, and that a number of different soft tissue neoplasms may present with a clear cell pattern, making diagnosis and classification difficult.

The present investigation endeavors to characterize the mucosubstance content of 170 myxoid and chondromatous tumors and chordomas by histochemical methods. The results obtained using the critical electrolyte concentration (CEC) method as introduced by Scott and co-workers23,24 were compared with those obtained by staining with alcian blue and toluidine blue at different pH's with and without pretreatment with bovine testicular hyaluronidase. Tissues known biochemically to contain different heteroglycans were used as controls: synovial fluid and cock's comb (hyaluronic acid) stained with alcian blue up to a MgCl2 concentration of 0.1 M; fetal cartilage (chondroitin 4- and 6-sulphate) pulposus with notochordal remnants (keratan sulphate) up 10 1.0 M. The staining reaction of intramuscular myxoma and myxoid liposarcoma corresponded to that of synovial fluid and cock's comb (containing hyaluronic acid). Benign chondromatous tumors (osteochondroma, enchondroma, extraskeletal chondroma, chondromatosis in bursae, synovia, and tendon) as well as well-differentiated chondrosarcomas had a similar staining reaction to that of adult cartilage (containing keratan sulphate). However, the intensity of the reaction was lower in these tumors than in the adult cartilage, indicating that the keratan sulphate content of the tumors is lower. Most of the moderately well-differentiated chondrosarcomas, the poorly differentiated chondrosarcomas, and pulmonary metastases of chondrosarcoma, as well as mesenchymal chondrosarcoma and extra-skeletal chondrosarcoma possessed the same staining properties as fetal cartilage, known to contain chondroitin 4- and 6-sulphate but not keratan sulphate. A few of the moderately well-differentiated chondrosarcomas stained up to a MgCl2 concentration of 1.0 M. Three cases of poorly differentiated chondrosarcomas stained with alcian blue up to 0.35-0.45 M in the lowest differentiated areas, indicating the presence of sulphated heteroglycans, as chondroitin 4- and 6-sulphate. Most chordomas possessed the same staining properties as fetal cartilage; however, a few chordomas stained in the same way as notochordal remnants of nucleus pulposus (containing keratan sulphate), which are thought to be the origin of these tumors. The results of staining of the tumors in the present series with the Scott technique corresponds well with toluidine blue and alcian blue at different pH's with and without pretreatment of the sections with testicular hyaluronidase. Since bone and soft tissue tumors may contain varying mucosubstances depending on the tissue of origin and on differentiation, histochemical investigation of the heteroglycan content of these tumors may be a valuable diagnostic aid.

Recent advances in radiation therapy in the clinical management of patients with sarcoma of soft tissue are discussed. Radical dose radiation therapy combined with limited surgery has been shown to be highly effective as treatment of early to moderately advanced sarcomas of the extremities. Desmoid tumors which are nonresectable have been treated with moderate to high radiation doses with regular success. The multimodality treatment of rhadbomysarcoma of childhood has yielded a dramatic improvement in 2-year survival figures. This approach includes radiation therapy, multidrug and multicycle chemotherapy, and surgery. Finally, the dominant importance of the histologic grade of sarcoma to the prognosis is discussed in terms of a proposed clinical staging system.

The dominant factor determining treatment policy, when considering radiotherapy of a neoplastic disorder, is the biologic nature of the tumor process in relation to its spatial configuration. This is also the important factor determining curative tumor dose. With the exception of very small tumors and certain important radiosensitive conditions, it is the effect on normal tissues which defines the limits of irradiation and which effectively determines the prescription of dosage. The relationship between dose and volume is basic to this discussion and is considered with particular reference to the integrity of mesenchyme. When comparing the radiosensitivities of tumor and host tissues, it is important to compare like with like. The ultimate effect on a tumor is measured functionally, in terms of suppressing the only function by which the tumour is recognized--its capacity for indefinite proliferation--and reflected in 5- and 10-year cure rates. The effects on normal tissues should therefore be similarly measured in dynamic terms of the final functional state rather than on any transient structural appearance. These features are considered in relation to three different clinical situations: certain radiosensitive tumors, accessible primary tumors of limited sensitivity, and large tumors situated deeply. It is emphasized that curative treatment requires careful clinical appraisal of all the relevant features in each individual patient. The state of both tumor and host reaction may change significantly during the period of treatment and there is no alternative to continuous clinical observation using all the ancillary aids available.