Primary gastric synovial sarcoma: molecular diagnosis and prediction of prognosis

Anlotinib as a maintenance treatment for advanced soft tissue sarcoma after first-line chemotherapy (ALTER-S006): a multicentre, open-label, single-arm, phase 2 trial

Background

No standard maintenance treatment has been obtained to prolong the response duration of soft tissue sarcoma (STS) after first-line chemotherapy. In this study, we aimed to evaluate the efficacy and safety of anlotinib as a maintenance treatment after chemotherapy in STS.

Methods

In this multicentre, open-label, single-arm phase 2 trial, patients with advanced STS who achieved partial response or stable disease after first-line anthracycline-based chemotherapy were enrolled between April 2019 and January 2022. All patients received anlotinib as a maintenance treatment. The primary endpoint was progression-free survival (PFS) of anlotinib maintenance treatment. Other endpoints included overall survival (OS), objective response rate (ORR), disease control rate (DCR) and safety. This study is registered with ClinicalTrials.gov, NCT03890068.

Findings

At the data cut-off date (August 8, 2022), 49 patients were enrolled, including 17 with liposarcoma (35%) and 15 with leiomyosarcoma (31%). After a median follow-up of 17.1 months (IQR 9.0-27.2), the median PFS from the beginning of maintenance treatment was 9.1 months (95% CI 5.7-12.5), and the median OS was not reached, and the 1-year OS rate for anlotinib maintenance treatment was 98.0%. The best ORR and DCR were 16% (8/49, 95% CI 7-30) and 94% (46/49, 95% CI 83-99), respectively. Most of the treatment-related adverse events were grade 1-2. Of the grade 3-4 adverse events, the most common were hypertension (10%) and hand-foot syndrome reaction (6%).

Interpretation

Postchemotherapy maintenance treatment with anlotinib exhibits promising efficacy and tolerable toxicity in patients with advanced STS.

Funding

Chia Tai Tianqing Pharmaceutical Group Co., Ltd., the National Key Research and Development Program of China, and the National Natural Science Foundation of China.

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.

Carcinosarcoma and sarcomatoid carcinoma of the stomach: Two case reports

RATIONALE

Carcinosarcoma and sarcomatoid carcinoma of the stomach are rare, malignant, and biphasic tumors with high mortality. The differential diagnosis of these 2 diseases remains challenging. In the present study, we present 2 cases of carcinosarcoma and sarcomatoid carcinoma of the stomach.

PATIENT CONCERNS

A 54-year-old woman was admitted with complaints of epigastric pain for 4 months, but she became serious for 10 days accompanied by melena. A 75-year-old man was admitted with complaints of epigastric pain for 1 month.

DIAGNOSIS

The female had a Borrmann type III irregular ulcerative lesion (5.0 × 4.0 × 1.0 cm) originating from the gastric antrum. The male had Borrmann type I tumor polypoid exophytic (5.0 × 4.0 × 2.0 cm) in the fundus of stomach near the cardia. Both cases were identified as malignant neoplasms by endoscopic biopsy and further confirmed by performing laparoscopic proximal gastrectomy, esophagogastrostomy, and palliative distal subtotal gastrectomy. The postoperative histopathological morphology and immunohistochemistry studies revealed sarcomatoid carcinoma for the female and gastric carcinosarcoma for the male respectively.

INTERVENTIONS

The female patient subsequently underwent laparoscopy-assisted radical distal gastrectomy for gastric cancer followed by systemic chemotherapy with oxaliplatin plus tegafur. The male patient underwent laparoscopic proximal gastrectomy and esophagogastrostomy were performed.

OUTCOMES

The female had a mixture of a little poorly-differentiated adenocarcinoma and abundant sarcomatoid spindle cell elements, and is still alive healthy up to date for 2 and a half years after surgery by phone follow-up. The male patient had both adenocarcinoma and fibrosarcoma in a single tumor, and died 1 month after the operation.

LESSONS

The present study provides insight into the clinical findings, differential diagnosis, and prognosis of carcinosarcomas and sarcomatoid carcinomas of the stomach. More cases are needed for further studies in the future.

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.

Monophasic synovial sarcoma of the greater omentum: case report and review of literature

Synovial sarcoma is a malignant spindle cell neoplasm normally arising from tissues around joints, bursa and tendon sheaths. Several reports involving the gastrointestinal tract, mainly the oesophagus and stomach, have been documented; however, the omentum remains an extremely unusual location. Monophasic type is composed exclusively of spindle cells arranged in fascicles. Establishing the correct diagnosis of these tumours could be challenging because of the similarities with gastrointestinal stromal tumours and other mesenchymal tumours with similar histology.

"Wild type" GIST: Clinicopathological features and clinical practice

Gastrointestinal stromal tumor (GIST) is a mesenchymal tumor of the gastrointestinal tract. Mutation of KIT and PDGFRA genes is implicated in the tumorigenesis. Approximately 10% of GISTs do not harbor mutation of these genes, and they are designated as "wild type" GIST. They are classified into succinate dehydrogenase (SDH)-deficient and non-SDH-deficient groups. SDH-deficient group includes Carney triad and Carney Stratakis syndrome. The patients are young women. Tumors occur in the antrum of the stomach, and tumor cells are epithelioid. Lymph node metastasis is frequent. The non-SDH-deficient group includes neurofibromatosis (NF) type 1 and GISTs with mutations of BRAF, KRAS, and PIK3CA and with the ETV6-NTRK3 fusion gene. GIST in NF occurs in the small intestine, and tumor cells are spindle shaped. GIST with BRAF mutation arises in the small intestine. Attention to the age, gender, family history and other neoplasms may raise the prediction of syndromic disease. Location of the tumor, morphology, and pleomorphism of the tumor cells are further informative. Lymphovascular invasion should be carefully evaluated. The determination of KIT expression is essential for the diagnosis. When wild type GIST is suspected, intensive genetic analysis is required. Further, a careful and long-time observation is recommended.

Abdominal monophasic synovial sarcoma is a morphological and immunohistochemical mimic of gastrointestinal stromal tumour

AIMS

Synovial sarcomas may arise within retroperitoneal or pelvic tissues or, more rarely, within the luminal gastrointestinal tract. This case series aims to demonstrate how such primary abdominal synovial sarcomas may particularly mimic gastrointestinal stromal tumour (GIST) on both morphological and immunohistochemical grounds.

METHODS AND RESULTS

Four cases of primary abdominal synovial sarcoma were reviewed morphologically and with immunohistochemistry, fluorescence in-situ hybridization with an SS18 break-apart probe, and KIT/PDGFRA mutation analysis. The four patients comprised two males and two females, with a median age of 42 years (range: 17-59 years). Two synovial sarcomas arose within the stomach, one within the small-intestine mesentery, and the fourth within the retroperitoneum. All four tumours showed only a monophasic spindle cell component in the tissues available for review. All four tumours showed DOG1 immunopositivity, and three coexpressed CD117. Three tested cases did not show activating KIT or PDGFRA mutations, whereas all four cases showed chromosomal rearrangement of SS18.

CONCLUSIONS

A diagnosis of synovial sarcoma should be considered particularly if an abdominal spindle cell neoplasm shows a haemangiopericytomatous pattern and diffuse CD99 and CD56 immunopositivity. A confident distinction between abdominal synovial sarcoma and GIST requires KIT/PDGFRA mutation analyses and specific molecular testing for synovial sarcoma.