Gastric Synovial Sarcoma

Primary Gastric Synovial Sarcoma in a Young Male: a Rare Case Report and Review of Literature

We are reporting a rare case of primary gastric synovial sarcoma in a young male. Synovial sarcoma of the stomach is a very rare tumor. The common involved sites of occurrence of synovial sarcomas are upper and lower extremities. In the English literature, only 47 cases of primary synovial sarcoma of stomach have been reported. Spindle-shaped tumor cells are the basic content of synovial sarcomas with varying degrees of epithelial differentiation. The basic classification of synovial sarcoma depends on the histological pattern and the degree of differentiation and it is classified as monophasic, biphasic, and poorly differentiated. Synovial sarcoma presents with classical chromosomal translocation where they form fusion genes of SS18-SSX1, SS18-SSX2, and SS18-SSX4. Fluorescence in situ hybridization (FISH) and reverse transcription polymerase chain reaction (RT-PCR) are the molecular analysis techniques to detect these fusion genes. As the available literature support is limited, the role of adjuvant chemotherapy, radiation therapy, and intra-operative lymphadenectomy is still unclear. However, surgical resection with clear margin is the gold standard treatment.

A minute primary gastric synovial sarcoma with ulcer: a case report

Background

Synovial sarcomas are a rare type of high-grade sarcomas with unknown cell origin. They arise predominantly in the soft tissues but rarely in the stomach. We recently encountered a rare case of minute gastric synovial sarcoma.

Case presentation

A 61-year-old Japanese woman was pointed out edematous erosion at the body of the stomach. Biopsy specimen showed dense proliferation of spindle-shaped tumor cells mixed with smooth muscle fibers of the muscularis mucosae. Although the definite histological diagnosis was undetermined, the patient underwent laparoscopic wedge resection of the stomach. Histological examination of the resected sample revealed that the maximum diameter of the tumor was only 6 mm and that dense proliferation of rather uniform spindle tumor cells were observed mainly in the submucosa. Immunohistochemistry showed that they were positive for pan-keratin, CD99 and TLE1. SS18-SSX fusion-specific antibody gave diffuse positive staining to the tumor cells, and analysis using mRNA extracted from paraffin sections revealed that the tumor had SS18-SSX1 fusion gene. Thus, it was diagnosed as gastric synovial sarcoma, monophasic fibrous type.

Conclusions

Primary synovial sarcoma of the stomach is rare and only 47 cases have been reported in the English literature to date. The maximum diameter of the lesion of our case was 6 mm which is the smallest among them.

Primary gastric synovial sarcoma resected by laparoscopic endoscopic cooperative surgery of the stomach: a case report

Background

Primary gastric synovial sarcoma is extremely rare, only 44 cases have been reported so far, and there have been no reports of laparoscopic endoscopic cooperative surgery for this condition.

Case presentation

A 45-year-old male patient presented with gastric pain. Esophagogastroduodenoscopy was performed that led to the identification of an 8-mm submucosal tumor in the anterior wall of the antrum, and a kit-negative gastrointestinal stromal tumor was suspected following biopsy. On endoscopic ultrasonography, the boundary of the tumor, mainly composed of the second layer, was depicted as a slightly unclear low-echo region, and a pointless no echo region was scattered inside. A boring biopsy revealed synovial sarcoma. Positron emission tomography did not reveal fluorodeoxyglucose (¹⁸F-FDG) accumulation in the stomach or other organs. Thus, the patient was diagnosed with a primary gastric synovial sarcoma, and laparoscopic endoscopic cooperative surgery was performed. The tumor of the antrum could not be confirmed laparoscopically from the serosa, and under intraoperative endoscopy, it had delle on the mucosal surface, which was removed by a method that does not involve releasing the gastric wall. Immunohistochemistry showed that the spindle cells were positive for EMA, BCL-2 protein, TLE-1, and SS18-SSX fusion-specific antibodies but negative for KIT and DOG-1. The final pathological diagnosis was synovial sarcoma of the stomach. The postoperative course was good, and the patient was discharged from the hospital on the 11th postoperative day.

Conclusion

Resection with laparoscopic endoscopic cooperative surgery (LECS), which has not been reported before, was effective for small synovial sarcomas that could not be confirmed laparoscopically. With the combination of laparoscopic and endoscopic approaches to neoplasia with a non-exposure technique (CLEAN-NET) procedure, it was possible to excise the tumor with the minimum excision range of the gastric serosa without opening the stomach.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40792-021-01310-8.

Synovial sarcoma of the stomach: a case report and a systematic review of literature

Worldwide, 5-10% of soft tissue sarcoma cases in adults have been attributed to synovial sarcoma. It is often reported to occur near the joints of the arm, neck, and leg but rarely in the gastrointestinal tract. In this study, we report a case of synovial sarcoma arising in the stomach of a 59-year-old woman. Gastrointestinal endoscopy revealed an ulcerative and hemorrhagic tumor with marginal elevation in the fundus. Histological study showed that the tumor was composed of tightly packed spindle cells in bundles, and one of its component demonstrated significant mitotic activity (> 40/10 high-power fields) in several areas. The diagnosis was confirmed by the evidence of SS18 gene rearrangement, according to immunohistochemistry study, (including a novel SS18-SSX fusion-specific antibody), fluorescent in situ hybridization, and the identification of the SS18-SSX1 and SS18-SSX1/2/4 fusion transcripts using reverse-transcript polymerase chain reaction. No evidence of local recurrence or distant metastasis has been found in the more than 5 years since. Distinguishing synovial sarcoma in the digestive tract from other mesenchymal neoplasms, such as gastrointestinal stromal tumor, may be difficult, especially when spindle-shaped cell proliferation is predominant, as in our patient. Therefore, morphological, immunohistological, and molecular evaluations are important for a comprehensive diagnosis.

Primary rectal monophasic synovial sarcoma

Synovial sarcoma is a rare malignant mesenchymal neoplasm that often occurs in the extremities. Less than 70 cases of primary synovial sarcoma occurring in the digestive system have been reported. We present a case of a 48-year-old woman with a spindle cell tumor in the rectum that stained positive for AE1/3 (focal), vimentin, CD99, BCL2, EMA (focal), and MiB-1 (15%). Ultimately, the lesion was diagnosed as a primary rectal monophasic synovial sarcoma and confirmed by molecular testing for SYT/SSX1 gene fusion. Analysis of previous publications indicated that patients of advanced age or a large tumor size (≥5 cm) have a higher risk of progressing rapidly to death after diagnosis of synovial sarcoma in the digestive system.

Laparoscopic intragastric resection of gastric synovial sarcoma: report of the first ever case with video demonstration

BACKGROUND

Synovial sarcoma (SS) is a rare soft tissue tumor. Among different anatomical locations where it can be found, gastric localization is a very uncommon one. Based on soft tissue sarcoma guidelines, complete tumor excision is considered the main treatment approach. Depending on size and localization of the tumor, both wedge and major gastric resections have been performed in the past for the treatment of this condition.

CASE PRESENTATION

We present the case of a 43-year-old woman who underwent a laparoscopic intragastric excision of a gastric 10-mm SS located nearby the esophagogastric junction. Pathology examination confirmed the presence of a SS. The resected specimen confirmed margin-free excision of a monophasic spindle cell neoplasm invading the submucosa and presenting the rearrangement of SS18 gene at fluorescence in situ hybridization (FISH). No adjuvant treatment was offered, and 18 months after surgery, the patient was alive and disease free.

CONCLUSIONS

This represents the first case reported in literature of a laparoscopic intragastric resection for a gastric SS. This approach allowed to obtain a full thickness radical tumor resection with the advantages of minimally invasive and organ preserving surgery.

Primary Gastric Synovial Sarcoma in a Child: A Case Report and Review of the Literature

Synovial sarcoma is a mesenchymal neoplasm that shows a specific t(X;18) translocation that leads to the formation of SS18-SSX gene fusions and is most commonly seen in soft tissues of the extremity. The gastrointestinal tract is a very rare site of involvement. We report a case of primary gastric synovial sarcoma in a 13-year-old male child. Synovial sarcoma should be included in the differential diagnosis when spindle cell neoplasms are encountered in the stomach. A high degree of suspicion, followed by the necessary immunohistochemistry and molecular studies, is required to make an accurate diagnosis.

Primary gastric synovial sarcoma: A case report and literature review

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Primary synovial sarcoma (SS) of the stomach is a very rare disease.

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To date, only 39 gastric SS cases have been reported in the literature.

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Here is a report of a surgically resected primary gastric SS case and a review of the corresponding literature.

Introduction

Synovial sarcoma (SS) is a mesenchymal neoplasm that is characterized by its unique histological pattern and is most commonly found near the joints of the extremity. Stomach involvement is very rare. This work aimed to present the case of a patient with gastric SS. We also conducted a review of 39 gastric SS cases reported in the literature.

Presentation of case

Here we report a case of primary gastric synovial sarcoma in a 32-year-old male patient revealed by gastric reflux. Partial gastrectomy was performed showing a 35 mm lesion with a high spindle cell component. Immunohistochemistry revealed 18q11.2 translocation expression in most of the cells asserting a diagnosis of SS. No local or distant recurrence occurred at 8 months post-operative follow-up.

Discussion

The majority of SS occurs in the extremities and is most often associated with tendons in the large articulations of young adults. Gastric SS are very scarce and a molecular biology approach to detect the SYT-SSX fusion gene is required for conclusive diagnosis. We carried out a clinical review of the 40 cases of primary gastric SS, including our case. They all underwent an excisional surgery, most of them by partial gastectomy or wedge resection. Recurrences were rare and early when they occurred.

Conclusion

Gastric SS is a very uncommon neoplasia although it is henceforth a described entity. Immunohistochemical detection of a pathognomonic translocation is needed to make the diagnosis of SS. Best therapeutic approach for these tumors remains surgical resection with no specific excisional technique recommended.