Case Reports Extraskeletal Myxoid Chondrosarcoma with "Chordoid" Features (Chordoid Sarcoma) AMIRA R. MEHIO, M.D., AND ALEX FERENCZY, M.D.
THE SO-CALLED "chordoid sarcoma," a rare, morphologically distinctive malignant growth, most commonly occurs in the soft tissue of the extremities. 12 The term "chordoid" is purely descriptive for some 12 and refers to its close histologic resemblance to chordoma. Others, 11 however, have expressed the view that misplaced notochord-like cells in an extramidline location may be the cell of origin for this lesion, and proposed the term "parachordoma." Based on the ultrastructural features of a single case of chordoid sarcoma arising in the flank, Weiss 17 proffered that the tumor bears a close resemblance to extraskeletal, myxoid chondrosarcoma rather than chordoma. In spite of a lack of cartilaginous differentiation in chordoid sarcoma, 12 the neoplastic cells Received July 28, 1977; received revised manuscript September 13, 1977; accepted for publication September 13, 1977. Supported in part by Grant MA 5137 from the Medical Research Council of Canada. Dr. Mehio's present address is Department of Pathology, Berbir Medical Center, P.O. Box 114302, Beirut, Lebonon. Address reprint requests to Dr. Ferenczy: Department of Pathology, Jewish General Hospital, 3755 Cote Ste. Catherine Road, Montreal, P. Q., H3T 1E2 Canada.
Department of Pathology and Obstetrics and Gynecology, McGill University, and Gynecologic Pathology and Cytology Services of the Jewish General Hospital, Montreal, Quebec, Canada
produce an abundant matrix of sulfated acid mucopolysaccharide interspersed with collagen fibers in different stages of maturation. 17 Such an extracellular matrix is considered characteristic of chondroitin sulfate and is elaborated by mesenchymal cells with either the potential for or evidence of cartilaginous differentiation. 2 > 6714 The relative paucity of information concerning the ultramorphologic features of chordoid sarcoma has prompted the authors to report their own electron microscopic observations of another example of this peculiar neoplasm. Report of a Case In November 1976, an 82-year-old white man sought treatment at the Jewish General Hospital for a large upper abdominal mass of four months' duration, associated with a 25-pound weight loss. On x-ray of the abdomen, a large mass was described to occupy the area of the gastrocolic ligament. A skeletal survey and gastrointestinal series were negative. The tumor was sampled by means of fine-needle aspiration technic. Several minute fragments of whitish, mucoid tissue were obtained, and the morphologic diagnosis of a soft-tissue sarcoma with a histologic pattern consistent with "chordoid sarcoma" was made (76-16087). The patient was discharged and given supportive therapy, but was readmitted three months later for partial gastrointestinal obstruction. He died on the day after admission, and an autopsy was performed. At autopsy the tumor was found to be confined to the abdominal cavity. It occupied the gastrocolic area, with extension to the omentum and peritoneum. Extension into the abdominal organs or bones was not demonstrated. The lumen of the transverse colon and left descending colon was segmentally narrowed by tumor masses. On sectioning, the tumor appeared soft, lobulated, whitish-gray, with areas of mucoid appearance and extensive necrosis. The immediate causes of death were considered to be bilateral bronchopneumonia and pulmonary edema. For light microscopic examination, multiple fragments from the omentum and the peritoneum were taken and fixed in 10% buffered
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Mehio, Amira R., and Ferenczy, Alex: Extraskeletal myxoid chondrosarcoma with "chordoid" features (chordoid sarcoma). Am J Clin Pathol 70: 700-705, 1978. The light and electron microscopic features of a so-called chordoid sarcoma arising in the area of the gastrocolic ligament are described and illustrated. Despite the tumor's histologic resemblance to chordoma, the ultrastructural markers are those of chondroid rather than chordoid neoplasms. These are well-developed, vesicular granular endoplasmic reticulum, intracytoplasmic glycogen, lipid bodies, and a collagen-poor extracellular matrix with electron-dense granules, presumably representing chondroitin sulfate. Similar submicroscopic alterations have been observed in extraskeletal myxoid chondrosarcomas. Because of the distinctive morphologic appearance of this peculiar lesion, the term "myxoid chondrosarcoma with chordoid features" is suggested to reconcile histologic and ultrastructural features and histogenesis. (Key words: Myxoid chondrosarcoma; Chordoid sarcoma; Ultrastructure.)
Vol. 70 • No. 4