EWING SARCOMA Figure 5-12 EWING SARCOMA Resection of residual Ewing sarcoma post-therapy shows a partial response to therapy, with fibrous scarring and cystic degeneration, although areas of viable tumor remain. More

PRIMARY SYNOVIAL SARCOMA OF THE PLEURA Figure 5-9 PRIMARY SYNOVIAL SARCOMA OF THE PLEURA Top: A part solid, part cystic mass occupies the pleural space. Bottom: A separate case shows a focally hemorrhagic solid mass filling the pleural space. More

PRIMARY SYNOVIAL SARCOMA OF THE PLEURA Figure 5-10 PRIMARY SYNOVIAL SARCOMA OF THE PLEURA Left: At low power, a cellular hyperchromatic tumor expands the pleural space. There is a fibrous pseudocapsule. Right: At high power, there are sheets of small spindle cells with relatively uniform morphol... More

EWING SARCOMA Figure 5-13 EWING SARCOMA A: The tumor consists of sheets of mitotically active “small round blue cells.” B: Most of the tumor (seen in fig. 5-12 ), has responded to therapy, with cystic change and dense fibrosis containing scattered hemosiderin-laden macrophages. C: CD99 stainin... More

PRIMARY PLEURAL SARCOMA Figure 5-19 PRIMARY PLEURAL SARCOMA A,B: A primary malignant peripheral nerve sheath tumor presents as a nodular mass between two ribs. C: A primary chondrosarcoma arises from a rib and extends to involve the pleural space. If no origin from bone is seen in tumors contain... More

BIPHASIC MESOTHELIOMA Figure 3-121 BIPHASIC MESOTHELIOMA The morphology of this pleural tumor resembles synovial sarcoma. However, it was negative for t(X;18). More

CLEAR CELL SARCOMA OF THE KIDNEY Figure 1-82 CLEAR CELL SARCOMA OF THE KIDNEY Clear cell sarcoma of the kidney characteristically entraps single tubules at its interface with the kidney. More

SYNOVIAL SARCOMA Figure 2-377 SYNOVIAL SARCOMA Synovial sarcoma of the kidney forms a large, mainly solid mass, with scattered small cysts and foci of hemorrhage and necrosis. More

SYNOVIAL SARCOMA Figure 2-378 SYNOVIAL SARCOMA This monophasic spindle cell synovial sarcoma aggressively invades native renal parenchyma, engulfing renal tubules and glomeruli. More

CLEAR CELL SARCOMA OF THE KIDNEY Figure 1-79 CLEAR CELL SARCOMA OF THE KIDNEY Clear cell sarcomas of the kidney are homogeneous, mucoid, and often irregular in contour. The tumor-kidney junction appears sharply defined grossly. More

SYNOVIAL SARCOMA Figure 2-379 SYNOVIAL SARCOMA Most renal synovial sarcomas are monophasic spindle cell neoplasms, composed of short, ill-defined, intersecting fascicles of spindle cells with plump nuclei. More

SYNOVIAL SARCOMA Figure 2-380 SYNOVIAL SARCOMA Many renal synovial sarcomas are extensively cystic, due to dilatation transforming entrapped, non-neoplastic renal tubules into large cysts. More

CLEAR CELL SARCOMA OF THE KIDNEY WITH LYMPH NODE METASTASIS Figure 1-99 CLEAR CELL SARCOMA OF THE KIDNEY WITH LYMPH NODE METASTASIS This subtle metastasis is present in the subcapsular area at the left of the figure. Clear cell sarcoma of the kidney frequently permeates lymphatics and involves ly... More

PRIMARY RENAL SCLEROSING EPITHELIOID FIBROSARCOMA MIMICKING CLEAR CELL SARCOMA OF THE KIDNEY Figure 1-97 PRIMARY RENAL SCLEROSING EPITHELIOID FIBROSARCOMA MIMICKING CLEAR CELL SARCOMA OF THE KIDNEY Left: At low power, the hyalinized fibrotic stroma, clear cytoplasm of the neoplastic cells, and embryonal hyperplasia of single entrapped tubules suggest the diagnosis of clear cell sarcoma of the kidney. Right: At higher power, the nuclear hyperchromasia and extensive ropy collagen are not typical of clear cell sarcoma, and instead support sclerosing epithelioid fibrosarcoma, which demonstrates an EWSR1-CREB3L1 gene fusion. More