summary Synovial Sarcoma is a malignant, soft tissue sarcoma caused by a t(X;18) chromosomal translocation mutation most commonly found near joints, but rarely within the joint. The condition usually presents in patients between 15 and 40 years old with a growing mass in proximity to a joint. Diagnosis is made with a biopsy showing a classic biphasic appearance with atypical spindle cells and epithelial cells. Immunostaining is positive for epithelial membrane antigen and vimentin. Treatment is usually wide surgical excision with radiation. Epidemiology Demographics most common sarcoma found in young adults (15-40 years) affects more males than females Anatomic location it is the most common malignant sarcoma of the foot Etiology Mechanism cellular origin of synovial sarcoma is unknown, but it is not the synovial cell or any cell involved in the synovium the name synovial sarcoma is a misnomer. Pathophysiology metastasis synovial sarcoma typically shows high histologic grade metastasis may develop in 30-60% of patients like other sarcomas, the lung is most common site of metastasis synovial sarcoma has been shown to have similar rates of lymph node metastasis compared to other soft tissue sarcomas the sarcomas which can metastasize to lymph nodes include angiosarcoma clear cell sarcoma rhabdomyosarcoma epithelioid sarcoma can stage with lymph node biopsy while lymph node metastasis is a poor prognostic sign, it is not as bad as lung metastasis metastasis is more common with large, deep, and high grade sarcomas Genetics chromosomal translocation t(X;18) is observed in more than 90% of cases translocation forms the SYT-SSX1, 2, or 4 fusion protein SYT-SSX4 is rare SYT-SSX1 vs. SYT-SSX2 SYT-SSX1 SYT-SSX2 Frequency More common (60% of tumors) Less common (40% of tumors) Histology type Biphasic Monophasic Gender M:F = 1:1 M:F = 1:2 Presentation Larger, with metastases Smaller, without metastases Survival Worse Better Presentation Symptoms typically present as a growing mass in proximity to a joint may be painless or painful most commonly occur in periarticular locations knee, shoulder, elbow, foot 60% are found in the lower extremity Physical exam check for regional lymphadenopathy Imaging Radiographs can show soft tissue mineralization (calcification) in these tumors may resemble heterotopic ossification CT can show calcification in the soft tissue mass MRI MRI reveals a heterogenous mass that is typically dark on T1 weighted images and bright on T2 weighted images Histology Characteristic findings classical synovial sarcoma shows a biphasic appearance with two typical cell types spindle cells (fibrous type of cells) relatively small and uniform and found in sheets of malignant appearing cells with minimal cytoplasm and dark atypical nuclei epithelial cells gland, nest, or cyst-like cells rarely, synovial sarcoma can also present with poorly differentiated or monophasic fibrous cell histology, consisting only of sheets of spindle cells cellular origin of synovial sarcoma is unknown, but it is not the synovial cell or any cell involved in the synovium. The name SYNOVIAL sarcoma is a misnomer Immunostaining for synovial sarcoma stains positive for vimentin epithelial membrane antigen sporadic S-100 epithelial cells stain positive for keratin Treatment Operative wide surgical resection with adjuvant radiotherapy indications standard of care in most patients technique radiotherapy may be delivered either pre-surgery or post-surgery chemotherapy data regarding chemotherapy in synovial sarcoma suggests that chemotherapy may improve both local control and overall survival Prognosis Overall prognosis is poor 5 year survival is approximately 50% 10 year survival is approximately 25% SYT-SSX fusion type is most important prognostic factor SYT-SSX2 better survival
QUESTIONS 1 of 21 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 Previous Next (OBQ18.134) A 40-year-old patient presents with a mass in the left great toe that has increased in size over the last several months. The patient denies any fevers or chills. Figure A demonstrates an AP radiograph of the left foot. Figure B is the biopsy of the lesion. Genetic analysis reveals an SYT-SSX1 fusion protein. Which of the following is true of this tumor compared to SYT-SSX2 translocation? QID: 213030 FIGURES: A B Type & Select Correct Answer 1 Smaller with less metastases 4% (76/2036) 2 Monophasic 12% (235/2036) 3 Better prognosis 31% (633/2036) 4 Biphasic 40% (822/2036) 5 Less common 12% (254/2036) L 4 Question Complexity A Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 4 Review Tested Concept Review Full Topic Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK (OBQ15.176) Figures A through E represent histological images (low power, left; high power, right) of primary sarcomas of bone and soft tissue. Which of the following figures is characteristic of a t(X;18) translocation? QID: 5861 FIGURES: A B C D E Type & Select Correct Answer 1 Figure A 7% (125/1812) 2 Figure B 44% (791/1812) 3 Figure C 22% (403/1812) 4 Figure D 15% (280/1812) 5 Figure E 11% (197/1812) L 4 Question Complexity A Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 2 Review Tested Concept Review Full Topic Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK (OBQ13.17) Which of the following tumors associated with the fusion protein SYT-SSX1 can metastasize via the lymph nodes? QID: 4652 Type & Select Correct Answer 1 Alveolar rhabdomyosarcoma 3% (133/4470) 2 Epitheliod sarcoma 4% (180/4470) 3 Clear cell sarcoma 5% (213/4470) 4 Angiosarcoma 2% (110/4470) 5 Synovial sarcoma 85% (3811/4470) L 2 Question Complexity B Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 5 Review Tested Concept Review Full Topic Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK (OBQ11.98) Which of the following fusion proteins is associated with synovial sarcoma? QID: 3521 Type & Select Correct Answer 1 BCR-ABL 1% (33/2660) 2 SYT-SSX 90% (2391/2660) 3 EWS-FLI1 3% (82/2660) 4 FUS-CHOP 2% (58/2660) 5 COL1A1-PDGFB 3% (80/2660) L 1 Question Complexity C Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 2 Review Tested Concept Review Full Topic Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK (OBQ08.236) All of the following statements regarding synovial sarcoma are correct EXCEPT? QID: 622 Type & Select Correct Answer 1 Typically occur around the joints of the upper or lower limb 10% (115/1150) 2 Immunohistochemisty is positive for cytokeratin and epithelial membrane antigen 10% (112/1150) 3 Histology is named because the cell line of origin is the type II synovial cell 63% (722/1150) 4 May show biphasic or monophasic histology 8% (91/1150) 5 Classic age range is the younger adult < 40 years of age 9% (100/1150) L 1 Question Complexity C Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 3 Review Tested Concept Review Full Topic Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK (OBQ08.15) A 22-year-old female has a painful foot mass. Clinical photo, MRI, and histology slide are shown in Figures A through C. What is the most likely diagnosis? QID: 401 FIGURES: A B C Type & Select Correct Answer 1 Osteosarcoma 1% (27/2795) 2 Morton's neuroma 3% (73/2795) 3 Synovial sarcoma 61% (1702/2795) 4 Fibrous dysplasia 5% (142/2795) 5 Desmoid tumor 30% (839/2795) L 2 Question Complexity C Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 3 Review Tested Concept Review Full Topic Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK (OBQ05.72) Which of the following is the most common sarcoma found in the foot? QID: 958 Type & Select Correct Answer 1 Epithelioid Sarcoma 11% (383/3425) 2 Liposarcoma 2% (71/3425) 3 Fibrosarcoma 8% (259/3425) 4 Synovial sarcoma 78% (2661/3425) 5 Adamantinoma 1% (35/3425) L 1 Question Complexity C Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 4 Review Tested Concept Review Full Topic (OBQ05.253) The chromosomal translocation t(X;18)is found in which of the following conditions? QID: 1139 Type & Select Correct Answer 1 Myxoid liposarcoma 4% (95/2130) 2 Synovial Sarcoma 82% (1744/2130) 3 Osteosarcoma 2% (52/2130) 4 Ewing's Sarcoma 7% (149/2130) 5 Clear cell sarcoma 4% (79/2130) L 2 Question Complexity B Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 2 Review Tested Concept Review Full Topic (OBQ05.16) A 33-year-old male presents with a painful mass in his axilla. Radiographs, MRI, and histology are shown in Figures A-C. The tumor stains positive for vimentin and epithelial membrane antigen on immunohistochemistry. What is the most likely diagnosis? QID: 53 FIGURES: A B C Type & Select Correct Answer 1 Synovial sarcoma 64% (988/1533) 2 Liposarcoma 10% (154/1533) 3 Malignant fibrous histiocytoma 22% (339/1533) 4 Osteosarcoma 1% (10/1533) 5 Chondrosarcoma 2% (34/1533) L 2 Question Complexity C Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 1 Review Tested Concept Review Full Topic (OBQ04.172) Which of the following histology images represents a synovial sarcoma? QID: 1277 FIGURES: A B C D E Type & Select Correct Answer 1 Figure A 61% (928/1516) 2 Figure B 3% (41/1516) 3 Figure C 13% (202/1516) 4 Figure D 9% (136/1516) 5 Figure E 13% (202/1516) L 3 Question Complexity D Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 1 Review Tested Concept Review Full Topic
All Videos (0) Podcasts (2) Pathology⎪Synovial Sarcoma Pathology - Synovial Sarcoma Listen Now 12:30 min 10/16/2019 307 plays 5.0 (2) Question Session⎪Synovial Sarcoma & Humeral Shaft Fractures Orthobullets Team Pathology - Synovial Sarcoma Listen Now 23:9 min 11/8/2019 50 plays 0.0 (0)