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

Abstract

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.

The role of DOG1 immunohistochemistry in dermatopathology

“…In testicular tissues, DOG1 immunoreactivity is observed in spermatocytes, spermatids and the luminal borders of the epididymis and rete testis . The various tumor types reported to express DOG1 are presented in Table . In particular, DOG1 immunoexpression in salivary gland tumors has been investigated in detail, and DOG1 has been practically applied as a marker of salivary acinar and intercalated duct differentiation .…”

Gastric synovial sarcoma: a case report and literature review

“…11 A clinical summary of the 36 cases of primary gastric synovial sarcoma, including our case, is shown in the Table. [8][9][10][12][13][14][15][16][17][18][19][20][21][22][23] When a gastric spindle cell tumour is encountered, the differential diagnosis mainly focuses on other gastrointestinal mesenchymal tumours, such as GIST, leiomyoma, leiomyosarcoma, schwannoma and fibromatosis. Appropriate immunohistochemical staining is crucial in order to make a diagnosis of synovial sarcoma.…”

High-risk gastrointestinal stromal tumour (GIST) and synovial sarcoma display similar angiogenic profiles: a nude mice xenograft study

“…Early in tumorigenesis, an angiogenic switch is activated by hypoxia, promoting the expression of pro-angiogenic growth factors, such as the VEGF family, its receptors, and HIF1α among others [7]. Recent publications have highlighted the difficulties in differentiating between GIST and monophasic intra-abdominal SS, where molecular mutations are sometimes the only distinguishing feature [27]. It has been suggested that it would be particularly informative to explore possible relationships between the presence of vasculogenic structures and the response to antiangiogenesis therapy [30, 31].…”

“…The differential diagnosis with a high-grade GIST may be difficult [26, 27]. Both tumour types cause metastasis and display an aggressive behaviour, suggesting that molecular reorganisations such as of SYT–SSX gene translocation and KIT mutations might be similarly essential for the growth of angiogenic factors.…”

“…Both tumour types cause metastasis and display an aggressive behaviour, suggesting that molecular reorganisations such as of SYT–SSX gene translocation and KIT mutations might be similarly essential for the growth of angiogenic factors. A recent publication described an intra-abdominal monophasic spindle cell SS that mimicked the morphology and immunohistochemistry of a high-risk spindle cell GIST [27]. …”