2 | CASE REPORT
We report a case of rapidly progressive synovial sarcoma with multiple metastases. A 34-year-old young man complained of radiating pain in the left lower extremity for 1 week. X-ray examination of the hip was performed in another hospital and was misdiagnosed as lumbar disc herniation. Later, in our hospital, the diagnosis was made of soft tissue sarcoma of the left hip with pulmonary metastasis. We performed a biopsy procedure on the patient. The postoperative pathology report was poorly differentiated synovial sarcoma. Intussusception and liver metastases were found 1 week after surgery, and then rapidly deteriorated and died. We performed a high-throughput gene comparison with 2 synovial sarcoma patients of the same age and type with good prognosis. The study found that this patient had a significant genetic mutation compared to patients with a good prognosis.
The patient was previously healthy, denied a history of chronic disease and immune system disease, had no recent renovation of the house, and had no radiation exposure. He denied history of smoking or drinking, but stayed up late frequently. He denied any family history of cancer and sarcoma.
The left hip soft tissue density increased on the X-ray before admission, but it was relatively insidious and there was a significant increase in soft tissue tension in the left hip. Admission laboratory values revealed a anaemia with hemoglobin of 82 g/L and hypoalbuminemia of 23.1 g/L, D-dimer 5.31mg/L. After admission, the patient’s first fecal routine suggested occult blood positive. MRI showed multiple irregular occupying tumor around the left hip with uneven mixed signals and lobulation. CT demonstrated multiple solid nodules in the lungs (Figure 1).
We performed biopsy for the patient. The postoperative pathological results showed that the tumor was poorly differentiated synovial sarcoma. Immunohistochemistry: Vimentin(+++), TLE1(+++), CD99(++), WT-1(++), Bcl- 2(++) , CKpan(-) , CK7(-) ,EMA(-) , S-100(-) , STAT6(-) , CD34(-) , CD31(-) , ERG(-) , SMA(-) , Desmin(-) , CD117(-) , calponin(-) , HBME-1(-) , calretinin(-) , ALK P80(-) , Ki-67(35%+)(Figure 2). One week after the operation, the patient complained of unbearable abdominal pain, and he underwent abdominal CT scan + enhancement. The results showed that the ascending colon was unevenly thickened with intussusception, and there were multiple round lesions in the liver. After consultation with general surgery department, the patient was considered to have surgical indications, and he was transferred to general surgery department for continued treatment. Intestinal obstruction catheter drainage was temporarily administered. After 4 days, the patient’s abdominal pain worsened again. His pulmonary and liver nodules were significantly larger than 4 days ago, the progress was rapid(Figure 3).
The patient’s family refused to undergo palliative bowel surgery, and the patient died three days after the last CT scan, less than a month from admission to death. In order to explore why the synovial sarcoma of this patient progressed so rapidly, we selected two patients with synovial sarcoma of the same age and gender with good prognosis as controls, performed peripheral blood high-throughput genome sequencing, and performed a preliminary comparative analysis of the results. The results showed that this patient had more significant gene mutations than the 2 patients with good prognosis. The Single Nucleotide Polymorphisms(SNP) showed that the mutation types were mainly homozygous mutations, and the number of mutations was significantly up-regulated in each mutation type(Table 1). The visual scatter plot and volcano plot showed that 820 and 822 genes were up-regulated, and 326 and 225 genes were down-regulated, respectively. The patient and the two controls had a significant intersection on the differential mutation catalog. GO and KEGG results suggest that significantly enriched related pathological pathways include tumor immune examination, transcriptional dysregulation, osteoclast activity, antigen presentation, and T cell function (Figure 4).