Solitary fibrous tumor of the stomach with high-grade sarcomatous dedifferentiation

Abstract

Solitary fibrous tumors (SFT) are uncommon fibroblastic mesenchymal neoplasms that display a wide range of histologic behaviors. These tumors, which are estimated to account for 2% of all soft tissue neoplasms, typically follow a benign clinical course. However, it is estimated that 10–30% of SFTs are malignant and demonstrate aggressive behavior with local recurrence and metastasis up to several years after surgical resection. We report a case of SFT arising from the stomach, which is an exceptionally rare finding and has been reported only six times in the literature. Our case was complicated by diagnostic dilemma with GIST, highlighting the challenges of diagnosing and characterizing SFTs. Additionally, this tumor was associated with dedifferentiation into undifferentiated pleomorphic sarcoma. To our knowledge, there are no documented cases of a malignant SFT arising from the stomach to demonstrate dedifferentiation into an undifferentiated pleomorphic sarcoma.

Clinicopathological features of gastric inflammatory myofibroblastic tumor: Report of five cases

“…The immunophenotype is positive for CD99, CD34, Bcl-2 and vimentin in tumor cells; in addition, focal weak positive expression of CKpan, EMA, SMA, S-100 and desmin is present. ALK, CD68, CD163, CD21, CD23, β-catenin, CD117 and DOG1 are not expressed (26).…”

Clinicopathological features and differential diagnosis of gastrofibromatosis-like undifferentiated carcinoma

“…Immunophenotypic analysis demonstrated that these tumors were positive for CD34, signal transducer and activator of transcription (STAT)6, CD99, Bcl-2, and vimentin, focally weakly positive for CKpan, epithelial membrane antigen, SMA, S-100, and desmin, and negative for DX2 and villin. 22 , 23 5) Schwannomas are rare in the stomach and occur with a frequency similar to that of gastric leiomyoma. They often occur in the elderly, forming a 2- to 5-cm tumor in the stomach wall.…”

Complex treatment after pathohistological and immunohistochemical analysis in synchronous neoplasms - anorectal achromatic malignant melanoma and gastric extrapleural solitary fibrous tumor

“…Subsequently, it was found that SFT is localized not only in the intrathoracic organs and structures, but also in extrapleural areas, involving soft tissues and parenchymal organs [13]. SFTs make up <2% of all soft tissue tumors [14,15]. Gastric localization of SFTs is a very rare disease, which by 2018 was published in seven patients, one of whom with pronounced pathohistological dedifferentiation [15].…”

“…SFTs make up <2% of all soft tissue tumors [14,15]. Gastric localization of SFTs is a very rare disease, which by 2018 was published in seven patients, one of whom with pronounced pathohistological dedifferentiation [15]. For the first time in the English medical literature, a clinical case with synchronous tumors -rectal achromatic malignant melanoma and gastric solitary fibrous tumor is presented.…”